.rs .\" Troff code generated by TPS Convert from ITU Original Files .\" Not Copyright ( c) 1991 .\" .\" Assumes tbl, eqn, MS macros, and lots of luck. .TA 1c 2c 3c 4c 5c 6c 7c 8c .ds CH .ds CF .EQ delim @@ .EN .nr LL 40.5P .nr ll 40.5P .nr HM 3P .nr FM 6P .nr PO 4P .nr PD 9p .po 4P .rs \v | 5i' .sp 2P .LP \fBRecommendation\ I.431\fR .RT .sp 2P .sp 1P .ce 1000 \fBPRIMARY\ RATE\ USER\(hyNETWORK\ INTERFACE\ \(em\ LAYER\ 1\ SPECIFICATION\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.431'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.431 %' .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .LP \fB1\fR \fBIntroduction\fR .sp 1P .RT .PP This Recommendation is concerned with the layer 1 electrical, format and channel usage characteristics of the primary rate user\(hynetwork interface at the S and T reference points. In this Recommendation, the term \*QNT\*U is used to indicate network terminating layer\ 1 aspects of NT1 and NT2 functional groups, and the term \*QTE\*U is used to indicate terminal terminating layer\ 1 aspects of TE1, TA and NT2 functional groups, unless otherwise indicated. The terminology used in this Recommendation is very specific and not contained in the relevant terminology Recommendations. Therefore, Annex\ E to Recommendation\ I.430 provides terms and definitions used in this Recommendation. Interfaces for the 1544\ kbit/s primary rate and for the 2048\ kbit/s primary rate are described. It has been an objective that differences between the interface specifications for the two rates be kept to a minimum. .RT .sp 1P .LP 1.1 \fIScope and field of application\fR .sp 9p .RT .PP This specification is applicable to user\(hynetwork interfaces at 1544\ kbit/s and 2048\ kbit/s primary rates for ISDN channel arrangements as defined in Recommendation\ I.412. .RT .sp 2P .LP \fB2\fR \fBType of configuration\fR .sp 1P .RT .PP The type of configuration applies only to the layer 1 characteristics of the interface and does not imply any constraints on modes of operation at higher layers. .RT .sp 1P .LP 2.1 \fIPoint\(hyto\(hypoint\fR .sp 9p .RT .PP The primary rate access will support only the point\(hyto\(hypoint configuration. .PP Point\(hyto\(hypoint configuration at layer 1 implies that for each direction only one source (transmitter) and one sink (receiver) are connected to the interface. The maximum reach of the interface in the point\(hyto\(hypoint configuration is limited by the specification for the electrical characteristics of transmitted and received pulses and the type of interconnecting cable. Some of these characteristics are defined in Recommendation\ G.703. .RT .sp 1P .LP 2.2 \fILocation of interfaces\fR .sp 9p .RT .PP The electrical characteristics for both the 1544\ kbit/s case (\(sc\ 4.1) and the 2048\ kbit/s case (\(sc\ 5.1) apply at the interfaces\ I\da\uand\ I\db\udefined in Figure\ 1/I.431. .PP Examples of functional groups corresponding to TE and NT as used here are given in Recommendation\ I.411, \(sc\ 4.3. .RT .LP .rs .sp 12P .ad r \fBFigure 1/I.431, (N), p.\fR .sp 1P .RT .ad b .RT .LP .bp .sp 2P .LP \fB3\fR \fBFunctional characteristics\fR .sp 1P .RT .sp 1P .LP 3.1 \fISummary of functions (Layer 1)\fR | (see Figure 2/I.431) .sp 9p .RT .LP .sp 2 .ce \fBH.T. [T1.431]\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(90p) . .TE .nr PS 9 .RT .ad r \fBFigure 2/I.431 (comme tableau) [T1.431], p.\fR .sp 1P .RT .ad b .RT .LP .sp 2 .sp 1P .LP \fIB\(hychannel\fR .sp 9p .RT .PP This function provides for the bidirectional transmission of independent B\(hychannel signals each having a bit rate of 64\ kbit/s as defined in Recommendation\ I.412. .RT .sp 1P .LP \fIH\fR .sp 9p .RT .EF '% \fI0\(emchannel'' .OF '''\fI0\(emchannel %' .PP This function provides for the bidirectional transmission of independent H\d0\u\(hychannel signals each having a bit rate of 384\ kbit/s as defined in Recommendation\ I.412. .RT .sp 1P .LP \fIH\fR .sp 9p .RT .EF '% \fI1\(emchannels'' .OF '''\fI1\(emchannels %' .PP This function provides for the bidirectional transmission of an H\d1\u\(hychannel signal having a bit rate of 1536\ (H\d1\\d1\u) or 1920\ (H\d1\\d2\u)\ kbit/s as defined in Recommendation\ I.412. .RT .sp 1P .LP \fID\(hychannel\fR .sp 9p .RT .PP This function provides for the bidirectional transmission of one D\(hychannel signal at a bit rate of 64\ kbit/s as defined in Recommendation\ I.412. .bp .RT .sp 1P .LP \fIBit timing\fR .sp 9p .RT .PP This function provides bit (signal element) timing to enable the TE or NT to recover information from the aggregate bit stream. .RT .sp 1P .LP \fIOctet timing\fR .sp 9p .RT .PP This function provides 8\ kHz timing towards TE or NT for the purpose of supporting an octet structure for voice coders and for other timing purposes as required. .RT .sp 1P .LP \fIFrame alignment\fR .sp 9p .RT .PP This function provides information to enable the TE or NT to recover the time\(hydivision multiplexed channels. .RT .sp 1P .LP \fIPower feeding\fR .sp 9p .RT .PP This function provides for the capability to transfer power across the interface towards the NT1. .RT .sp 1P .LP \fIMaintenance\fR .sp 9p .RT .PP This function provides information concerning operational or failure conditions of the interface. The network reference configuration for maintenance activities on primary rate subscriber access is given in Recommendation\ I.604. .RT .sp 1P .LP \fICRC procedure\fR .sp 9p .RT .PP This function provides for the protection against false framing and may provide for error performance monitoring of the interface. .RT .sp 1P .LP 3.2 \fIInterchange circuits\fR .sp 9p .RT .PP Two interchange circuits, one for each direction, are used for the transmission of digital signals. All the functions listed above, with the exception of power feeding and possibly maintenance, are combined into two composite digital signals, one for each direction of transmission. .PP If power feeding via the interface is provided, an additional interchange circuit is used for power feeding. .PP The two wires of the pairs carrying the digital signal may be reversed if symmetrical wiring is provided. .RT .sp 1P .LP 3.3 \fIActivation/deactivation\fR .sp 9p .RT .PP The interfaces for the primary rate user\(hynetwork interface will be active at all times. No activation/deactivation procedures will be applied at the interface. However, to indicate the layer\ 1 transport capability to layer\ 2, the same primitive set is used as defined in Recommendation\ I.430. This provides for a unique application of the layer\ 1/layer\ 2 interface The primitives PH\(hyAR, MPH\(hyDR, MPH\(hyDI and MPH\(hyII are not required for this application and, therefore, they are not used in this Recommendation. .RT .sp 1P .LP 3.4 \fIOperational functions\fR .sp 9p .RT .PP In this section the term network is used to indicate either: .RT .LP \(em NT1, LT and ET functional groups in case of an interface at the T\ reference point; or .LP \(em relevant parts of the NT2 functional group in case of an interface at the S\ reference point. .PP The term TE (or \*Quser side\*U) is used to indicate terminal terminating layer\ 1 aspects of TE1, TA and NT2 functional groups. .sp 1P .LP 3.4.1 \fIDefinition of \fR \fIsignals at the interface\fR .sp 9p .RT .PP Signals exchanged between the network and user sides under normal and fault conditions are listed in Table\ 1/I.431. Further information on these signals is given in \(sc\ 4.7.3 and \(sc\ 5.9.1. .bp .RT .ce \fBH.T. [T2.431]\fR .ce TABLE\ 1/I.431 .ce \fBSignals between the network and user sides under normal\fR .ce .ce \fBand fault conditions\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(72p) | cw(120p) . Name List of the signals _ .T& lw(72p) | lw(120p) . Normal operational frame { Operational frame with: \(em active associated CRC bits \(em CRC error information (see Recommendation\ G.704) \(em no defect indication } _ .T& lw(72p) | lw(120p) . RAI { Operational frame with: \(em active associated CRC bits \(em CRC error information (Note) \(em with remote alarm indication, see Table\ 4a/G.704 (2048\ kbit/s systems only) } _ .T& lw(72p) | lw(120p) . LOS { No received incoming signal (Loss of signal) } _ .T& lw(72p) | lw(120p) . AIS { Continuous stream of ONEs (Recommendation\ M.20) } _ .T& lw(72p) | lw(120p) . CRC error information { E bit according to Recommendation\ G.704, Table\ 4b, set to \*QZERO\*U if CRC block is received with error (2048\ kbit/s systems only) } .TE .LP AIS Alarm indication signal .LP CRC Cyclic redundancy check .LP LOS Loss of signal .LP RAI Remote alarm indication .LP \fINote\fR \ \(em\ The 1544 kbit/s systems RAI and CRC\(hyderived error performance information cannot be sent simultaneously. Failure conditions may be sectionalized across the interface by obtaining additional information by means that are for further study. .nr PS 9 .RT .ad r \fBTableau 1/I.430 [T2.431], p.\fR .sp 1P .RT .ad b .RT .LP .sp 1 .sp 1P .LP 3.4.2 \fIDefinitions of state tables at network and user sides\fR .sp 9p .RT .PP The user side and network side of the interface have to inform each other on the layer\ 1 states in relation to the different defects that could be detected. .PP For that purpose, two state tables are defined, one at the user side and one at the network side. States at the user side (F\ states) are defined in \(sc\ 3.4.3 and states at the network side (G\ states) are defined in \(sc\ 3.4.4. The state tables are defined in \(sc\ 3.4.6. .PP Fault conditions FC1 to FC4 that could occur at the network side or between the network side and user side are defined in Figure\ 3/I.431. These fault conditions directly affect the F and G\ states. Information on these fault conditions are exchanged between the user and network sides in the form of signals defined in Table\ 1/I.431. .PP \fINote\ 1\fR \ \(em\ Only stable states needed for operation and maintenance of the user and the network side of the interface (system reactions, user and network relevant information) are defined. The transient states relative to the detections of the CRC error information are not taken into account. .PP \fINote\ 2\fR \ \(em\ The user does not need to know where a failure is located in the network. The user must be informed on the availability and the continuity of the layer\ 1 service. .PP \fINote\ 3\fR \ \(em\ The user has all information relative to the CRC associated with each direction of its adjacent CRC\ section. The supervision of the quality of this section is the user's responsibility. .bp .RT .LP .rs .sp 15P .ad r \fBFigure 3/I.431, (N), p.\fR .sp 1P .RT .ad b .RT .sp 1P .LP 3.4.3 \fILayer 1 states on the user side of the interface\fR .sp 9p .RT .PP \fIF0 state | Loss of power on the user side\fR .RT .LP \(em In general, the TE can neither transmit nor receive signals. .LP \fIF1 state | Operational state\fR .LP \(em Network timing and layer 1 service is available. .LP \(em The user side transmits and receives operational frames with associated CRC bits and with temporary CRC error information (Note\ 1). .LP \(em The user side checks the received frames and the associated CRC bits, and transmits to the network side operational frames containing the CRC error information, if a CRC error is detected. .LP \fIF2 state | Fault condition No. 1\fR .LP \(em This fault state corresponds to the fault condition FC1. .LP \(em Network timing is available at the user side. .LP \(em The user side receives operational frames with associated CRC bits and with temporary CRC error information (Note\ 1). .LP \(em The received frames contain RAI. .LP \(em The user side transmits operational frames with associated CRC\ bits. .LP \(em The user side checks the received frames and the associated CRC bits and transmits to the network side operational frames containing the CRC error information, if a CRC error is detected. .LP \fIF3 state | Fault condition No. 2\fR .LP \(em This fault state corresponds to the fault condition FC2. .LP \(em Network timing is not available at the user side. .LP \(em The user side detects loss of incoming signal (this will involve loss of frame alignment). .LP \(em The user side transmits operational frames with associated CRC\ bits and RAI (Note\ 2). .LP \fIF4 state | Fault condition No. 3\fR .LP \(em This fault state corresponds to fault condition FC3. .LP \(em Network timing is not available at the user side. .LP \(em The user side detects AIS. .LP \(em The user side transmits to the network side operational frames with associated CRC\ bits and RAI (Note\ 2). .bp .LP \fIF5 state | Fault condition No.\ 4\fR .LP \(em This fault state corresponds to the fault condition FC4. .LP \(em Network timing is available at the user side. .LP \(em The user side receives operational frames with continuous CRC error information (optional) (Note\ 3). .LP \(em The received frames contain RAI. .LP \(em The user side transmits operational frames with associated CRC\ bits. .LP \(em The user side checks the received frames and the associated CRC\ bits. It may transmit to the network side operational frames containing the CRC error information, if a CRC error is detected. .LP \fIF6 state | Power on state\fR .LP \(em This is a transient state and the user side may change the state after detection of the signal received. .LP \fINote\ 1\fR \ \(em\ The interpretation of the CRC error information depends on the option used in the network (see \(sc\ 5.9.2 and Recommendation\ I.604). .LP \fINote\ 2\fR \ \(em\ In 1544\ kbit/s systems, RAI and CRC\(hyderived error performance information cannot be sent simultaneously. Failure conditions may be sectionalized across the interface by obtaining additional information by means that are for further study. .LP \fINote\ 3\fR \ \(em\ Only in options\ 2 and 3 of Recommendation\ I.604, Annex\ A. The condition of \*Qcontinuous CRC error information\*U corresponds to loss of incoming signal or loss of frame alignment on the network side. .sp 1P .LP 3.4.4 \fILayer 1 states at the network side of the interface\fR .sp 9p .RT .PP \fIG0 state | Loss of power in the NT1\fR .RT .LP \(em In general, the NT1 can neither transmit nor receive any signal. .LP \fIG1 state | Operational state\fR .LP \(em The network timing and layer 1 service is available. .LP \(em The network side transmits and receives operational frames with associated CRC\ bits and temporary CRC error information. .LP \(em The network side checks the received frames and the associated CRC\ bits and transmits to the user side the CRC error information if a CRC error is detected. .LP \fIG2 state | Fault condition No.\ 1\fR .LP \(em This fault state corresponds to the fault condition FC1. .LP \(em Network timing is provided to the user side. .LP \(em The network side receives operational frames with associated CRC\ bits. .LP \(em The network side transmits to the user side operational frames with associated CRC\ bits and RAI. The operational frames may contain CRC error information (Note\ 1). .LP \fIG3 state | Fault condition No.\ 2\fR .LP \(em This fault state corresponds to the fault condition FC2. .LP \(em Network timing is not provided to the user side. .LP \(em The network side transmits to the user side operational frames with associated CRC\ bits. .LP \(em The network side receives operational frames with associated CRC\ bits and RAI (Note\ 2). .LP \fIG4 state | Fault condition No.\ 3\fR .LP \(em This fault state corresponds to the fault condition FC3. .LP \(em Network timing is not provided to the user side. .LP \(em The network side transmits AIS. .LP \(em The network side receives operational frames with associated CRC\ bits and RAI (Note\ 2). .LP \fIG5 state | Fault condition No.\ 4\fR .LP \(em This fault states corresponds to the fault condition FC4. .LP \(em Network timing is provided to the user side. .LP \(em The network side detects loss of incoming signal or loss of frame alignment. .LP \(em The network side transmits to the user side operational frames with associated CRC\ bits and RAI and continuous CRC error information (Notes\ 2 and 3). .bp .LP \fIG6 state | Power on state\fR .LP \(em This is a transient state and the network side may change the state after detection of the signal received. .LP \fINote\ 1\fR \ \(em\ The interpretation of the CRC error information depends on the option used in the network (see \(sc\ 5.9.2 and Recommendation\ I.604). .LP \fINote\ 2\fR \ \(em\ In 1544\ kbit/s systems, RAI and CRC\(hyderived error performance information cannot be sent simultaneously. Failure conditions may be sectionalized across the interface by obtaining additional information by means that are for further study. .LP \fINote\ 3\fR \ \(em\ Only in options\ 2 and 3 of Recommendation I.604, Annex\ A. .sp 1P .LP 3.4.5 \fIDefinition of primitive\fR .sp 9p .RT .PP The following primitives should be used between layers 1 and 2 (primitives PH) or between layer\ 1 and the management entity (primitives MPH). .RT .LP PH\(hyAI PH ACTIVATE INDICATION .LP PH\(hyDI PH DEACTIVATE INDICATION .LP MPH\(hyAI MPH ACTIVATE INDICATION (is used as error recovery and initialization information) .LP MPH\(hyEIn MPH ERROR INDICATION with parameter .LP n Parameter which defines the failure condition relevant to the reported error .sp 1P .LP 3.4.6 \fIState tables\fR .sp 9p .RT .PP Operational functions are defined in Table 2/I.431 for the layer\ 1 states at the user side of the interface and in Table\ 3/I.431 for the network side. The exact reaction in case of double faults may depend on the type of double fault condition and the sequence in which they occur. .RT .LP \fB4\fR \fBInterface at 1544 kbit/s\fR .sp 1P .RT .sp 2P .LP 4.1 \fIElectrical characteristics\fR .sp 1P .RT .sp 1P .LP 4.1.1 \fIBit rate\fR .sp 9p .RT .PP The signal shall have a bit rate of 1544\ kbit/s \(+- | 0 parts per million\ (ppm). .RT .sp 1P .LP 4.1.2 \fIInterchange circuit support\fR .sp 9p .RT .PP One symmetric metallic pair shall be used for each direction of transmission. .RT .sp 1P .LP 4.1.3 \fICode\fR .sp 9p .RT .PP The B8ZS code is recommended (see Note\ 1 under Table\ 4/I.431 for definition of B8ZS code). .RT .sp 2P .LP 4.1.4 \fISpecifications at the output ports\fR .sp 1P .RT .sp 1P .LP 4.1.4.1 \fITest load\fR .sp 9p .RT .PP Test load impedance shall be 100 ohms, resistive. .RT .sp 1P .LP 4.1.4.2 \fIPulse mask\fR .sp 9p .RT .PP An isolated pulse measured at interfaces I\da\uor \db\udefined in Figure\ 1/I.431 shall have an amplitude between 2.4 and 3.6\ volts measured at the centre of the pulse. .PP A possible normalized pulse mask is shown in Figure\ I\(hy1/I.431. This pulse mask is for further study. .PP An isolated pulse shall satisfy the requirements set out in Table\ 4/I.431. .bp .RT .ce \fBH.T. [1T3.431]\fR .ce TABLE\ 2/I.431 .ce \fBPrimary rate layer 1 state matrix at user side of the\fR .ce \fBinterface\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(24p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) . Initial state F0 F1 F2 | ub\d\u)\d F3 F4 F5 | ub\d\u)\d F6 _ .T& lw(24p) | lw(36p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) , ^ | l | l | l | l | l | l | l | l. Definition of the states { Operational condition or failure condition } Power off at user side Operational FC1 FC2\fR FC3 FC4 Power on at user side { Signal transmitted towards interface } No signal Normal operational frames Normal operational frames Frames with RAI Frames with RAI Normal operational frames No signal _ .T& lw(24p) | lw(36p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) , ^ | l | c | c | c | c | c | c | c ^ | l | c | c | c | c | c | c | c ^ | l | c | c | c | c | c | c | c ^ | l | c | c | c | c | c | c | c ^ | l | c | c | c | c | c | c | c ^ | l | c | c | c | c | c | c | c. { New event, detected at the receiving side } Loss of TE power / PH\(hyDI MPH\(hyEI0 F0 MPH\(hyEI0 F0 MPH\(hyEI0 F0 MPH\(hyEI0 F0 MPH\(hyEI0 F0 MPH\(hyEI0 F0 Return of TE power F6 / / / / / / { Normal operational frames from network side } / \(em PH\(hyAI MPH\(hyAI F1 PH\(hyAI MPH\(hyAI F1 PH\(hyAI MPH\(hyAI F1 PH\(hyAI MPH\(hyAI F1 / { Reception of RAI | ua\d\u)\d } / PH\(hyDI MPH\(hyEI1 F2 \(em MPH\(hyEI1 F2 MPH\(hyEI1 F2 MPH\(hyEI1 F2 MPH\(hyEI1 F2 { Loss of signal or frame alignment } / PH\(hyDI MPH\(hyEI2 F3 MPH\(hyEI2 F3 \(em MPH\(hyEI2 F3 MPH\(hyEI2 F3 MPH\(hyEI2 F3 Reception of AIS / PH\(hyDI MPH\(hyEI3 F4 MPH\(hyEI3 F4 MPH\(hyEI3 F4 \(em MPH\(hyEI3 F4 MPH\(hyEI3 F4 { Reception of RAI and continuous CRC error report | ua\d\u)\d } / PH\(hyDI MPH\(hyEI4 F5 MPH\(hyEI4 F5 MPH\(hyEI4 F5 MPH\(hyEI4 F5 \(em MPH\(hyEI4 F5 _ .T& lw(228p) . Single fault conditions .T& cw(12p) . . .T& cw(12p) | lw(216p) . \(em No state change .T& lw(12p) . .T& cw(12p) . . .T& cw(12p) | lw(216p) . / Impossible situation .T& lw(12p) . .T& cw(18p) . . .T& cw(18p) | lw(210p) . PH\(hyx MPH\(hyy Fz { Issue primitive x Issue management primitive y Go to state Fz } .T& lw(18p) . .TE .nr PS 9 .RT .ad r \fBTableau 2/I.431 [1T3.431], p. 5\fR .sp 1P .RT .ad b .RT .LP .bp .ce \fBH.T. [2T3.431]\fR .LP PH\(hyAI =\ PH ACTIVATE INDICATION .LP PH\(hyDI =\ PH DEACTIVATE INDICATION .LP MPH\(hyEIn =\ MPH ERROR INDICATION with parameter n (n = 0 to 4) .LP \ua\d\u)\d This event covers different network options. The network options 2 and 3 (see Recommendation\ I.604) of the 2048\ kbit/s system (which include CRC processing in the digital transmission link) provide CRC error information which allows the user\(hyside equipment to localize a fault, indicated by means of RAI, to either: .LP i) the network side (FC1), if frames without continuous CRC error reports are received; or .LP ii) the user side (FC4), if frames with continuous CRC error reports are received. .LP If network options oth er than 2 and 3 of the 2048 kbit/s system apply, the faults FC1 and FC4 are indicated identically at the interface, therefore, the signal \*QRAI with continuous CRC error report\*U does not occur. .LP \ub\d\u)\d This state covers two user options: .LP i) if a TE adopting the option to distinguish between F2 and F5 (given by options\ 2 and\ 3 of 2048\ kbit/s interfaces only) is used, but the network does not provide the distinction (see Note\ 1), then signal \*QRAI with continuous CRC error report\*U will not occur and the TE always enters state F2 on receipt of RAI; .LP ii) the user option of not processing CRC error information when accompanied with RAI, even if provided, merges states F2 and F5. .LP \fBH.T. [1T4.431]\fR TABLE\ 3/I.431 .ce \fBPrimary rate layer 1 state matrix at network side of .ce the interface\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(24p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) . Initial state G0 G1 G2 G3 G4 G5 | ua\d\u)\d G6 _ .T& lw(24p) | lw(36p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) , ^ | l | l | l | l | l | l | l | l. Definition of the states { Operational condition or failure condition as seen from the interface } Power off at NT Operational FC1 FC2\fR FC3 FC4 Power on at NT { Signal transmitted towards interface } No signal Normal operational frames RAI | ub\d\u)\d Normal operational frames AIS \ub\d\u)\d No signal _ .T& lw(24p) | lw(36p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) , ^ | l | c | c | c | c | c | c | c ^ | l | c | c | c | c | c | c | c ^ | l | c | c | c | c | c | c | ^ , ^ | ^ | ^ | ^ | ^ | c | c | c | c ^ | l | c | c | c | ^ | ^ | ^ | ^ , ^ | ^ | ^ | ^ | c | c | c | c | ^ , ^ | ^ | ^ | ^ | ^ | ^ | c | l | c ^ | c | c | c | c | c | ^ | ^ | ^ , ^ | ^ | ^ | ^ | c | c | c | c | ^ , ^ | ^ | ^ | ^ | ^ | ^ | ^ | l | c ^ | c | c | c | c | c | c | ^ | ^ , ^ | ^ | ^ | ^ | c | l | l | l | l. { New event detected at the receiving side } Loss of NT power / MPH\(hyEI0 PH\(hyDI G0 MPH\(hyEI0 G0 MPH\(hyEI0 G0 MPH\(hyEI0 G0 MPH\(hyEI0 G0 MPH\(hyEI0 G0 Return NT power G6 / / / / / / { Normal operational frames, no internal network failure } / \(em PH\(hyAI MPH\(hyAI G1 PH\(hyAI MPH\(hyAI G1 PH\(hyAI MPH\(hyAI G1 PH\(hyAI MPH\(hyAI G1 / Internal network failure FC1 / PH\(hyDI MPH\(hyEI1 G2 \(em MPH\(hyEI1 | uc\d\u)\d G2 MPH\(hyEI1 | uc\d\u)\d \(em MPH\(hyEI1 | uc\d\u)\d \(em . G2 G2 MPH\(hyEI1 G2 Reception of RAI FC2 / PH\(hyDI MPH\(hyEI2 G3 { MPH\(hyEI2 | uc\d\u)\d \(em } G3 { \(em MPH\(hyEI2 | uc\d\u)\d \(em MPH\(hyEI2 | uc\d\u)\d \(em } G3 G3 MPH\(hyEI2 G3 { Internal network failure FC3 } / PH\(hyDI MPH\(hyEI3 G4 MPH\(hyEI3 | uc\d\u)\d G4 MPH\(hyEI3 | uc\d\u)\d G4 . . \(em MPH\(hyEI3 | uc\d\u)\d G4 . MPH\(hyEI3 G4 { Loss of operational frames FC4 } / { PH\(hyDI MPH\(hyEI4 G5 MPH\(hyEI4 | uc\d\u)\d G5 MPH\(hyEI4 | uc\d\u)\d G5 } MPH\(hyEI4 | uc\d\u)\d G5 . . G5 \(em MPH\(hyEI4 G5 _ .TE .nr PS 9 .RT .ad r \fBTableau 2/I.431 [2T3.431], p. 6\fR .sp 1P .RT .ad b .RT .LP .rs .sp 33P .ad r Blanc .ad b .RT .LP .bp .ce \fBH.T. [1T4.431]\fR .ce TABLE\ 3/I.431 .ce \fBPrimary rate layer 1 state matrix at network side of .ce the interface\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(24p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) . Initial state G0 G1 G2 G3 G4 G5 | ua\d\u)\d G6 _ .T& lw(24p) | lw(36p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) | lw(24p) , ^ | l | l | l | l | l | l | l | l. Definition of the states { Operational condition or failure condition as seen from the interface } Power off at NT Operational FC1 FC2\fR FC3 FC4 Power on at NT { Signal transmitted towards interface } No signal Normal operational frames RAI | ub\d\u)\d Normal operational frames AIS \ub\d\u)\d No signal _ .T& lw(24p) | lw(36p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) , ^ | l | c | c | c | c | c | c | c ^ | l | c | c | c | c | c | c | c ^ | l | c | c | c | c | c | c | ^ , ^ | ^ | ^ | ^ | ^ | c | c | c | c ^ | l | c | c | c | ^ | ^ | ^ | ^ , ^ | ^ | ^ | ^ | c | c | c | c | ^ , ^ | ^ | ^ | ^ | ^ | ^ | c | l | c ^ | c | c | c | c | c | ^ | ^ | ^ , ^ | ^ | ^ | ^ | c | c | c | c | ^ , ^ | ^ | ^ | ^ | ^ | ^ | ^ | l | c ^ | c | c | c | c | c | c | ^ | ^ , ^ | ^ | ^ | ^ | c | l | l | l | l. { New event detected at the receiving side } Loss of NT power / MPH\(hyEI0 PH\(hyDI G0 MPH\(hyEI0 G0 MPH\(hyEI0 G0 MPH\(hyEI0 G0 MPH\(hyEI0 G0 MPH\(hyEI0 G0 Return NT power G6 / / / / / / { Normal operational frames, no internal network failure } / \(em PH\(hyAI MPH\(hyAI G1 PH\(hyAI MPH\(hyAI G1 PH\(hyAI MPH\(hyAI G1 PH\(hyAI MPH\(hyAI G1 / Internal network failure FC1 / PH\(hyDI MPH\(hyEI1 G2 \(em MPH\(hyEI1 | uc\d\u)\d G2 MPH\(hyEI1 | uc\d\u)\d \(em MPH\(hyEI1 | uc\d\u)\d \(em . G2 G2 MPH\(hyEI1 G2 Reception of RAI FC2 / PH\(hyDI MPH\(hyEI2 G3 { MPH\(hyEI2 | uc\d\u)\d \(em } G3 { \(em MPH\(hyEI2 | uc\d\u)\d \(em MPH\(hyEI2 | uc\d\u)\d \(em } G3 G3 MPH\(hyEI2 G3 { Internal network failure FC3 } / PH\(hyDI MPH\(hyEI3 G4 MPH\(hyEI3 | uc\d\u)\d G4 MPH\(hyEI3 | uc\d\u)\d G4 . . \(em MPH\(hyEI3 | uc\d\u)\d G4 . MPH\(hyEI3 G4 { Loss of operational frames FC4 } / { PH\(hyDI MPH\(hyEI4 G5 MPH\(hyEI4 | uc\d\u)\d G5 MPH\(hyEI4 | uc\d\u)\d G5 } MPH\(hyEI4 | uc\d\u)\d G5 . . G5 \(em MPH\(hyEI4 G5 _ .TE .nr PS 9 .RT .ad r \fBTableau 3/I.431 [1T4.431], p. 7\fR .sp 1P .RT .ad b .RT .LP .rs .sp 8P .ad r Blanc .ad b .RT .LP .bp .ce \fBH.T. [2T4.431]\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(228p) . Single fault conditions .T& cw(12p) . . .T& cw(12p) | lw(216p) . \(em No state change .T& lw(12p) . .T& cw(12p) . . .T& cw(12p) | lw(216p) . / Impossible situation .T& lw(12p) . .T& cw(18p) . . .T& cw(18p) | lw(210p) . PH\(hyx MPH\(hyy Gz { Issue primitive x Issue management primitive y Go to state Gz } .T& lw(18p) . .T& lw(228p) . Double fault conditions .T& cw(24p) . . .T& cw(24p) | lw(204p) . MPH\(hyy | uc\d\u)\d Gz { Second fault is dominant. Action to be taken when second fault occurs. } .T& lw(24p) . .T& cw(24p) . . .T& cw(24p) | lw(204p) . . { The disappearance of the first fault is not visible at the interface since the second fault is dominant and the state has changed already to Gz. } .T& lw(24p) . .T& cw(24p) . . .T& cw(24p) | lw(204p) . MPH\(hyy | uc\d\u)\d \(em { First fault is dominant, therefore the state will not change when the second fault occurs but the error indication may be given to the management if possible. } .T& lw(24p) . .T& cw(24p) . . .T& cw(24p) | lw(204p) . Gz { Action to be taken when first (dominant) fault disappears. } .T& lw(24p) . .T& lw(228p) . .TE .nr PS 9 .RT .ad r \fBTableau 3/I.431 [2T4.431], p. 8\fR .sp 1P .RT .ad b .RT .LP .rs .sp 2P .ad r Blanc .ad b .RT .LP .bp .ce \fBH.T. [T5.431]\fR .ce TABLE\ 4/I.431 .ce \fBDigital interface at 1544 kbit/s\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(96p) | lw(90p) . Bit rate 1544 kbit/s _ .T& lw(96p) | lw(90p) . { Pair(s) in each direction of transmission } One symmetric pair _ .T& lw(96p) | lw(90p) . Code B8ZS (Note\ 1) _ .T& lw(96p) | lw(90p) . Test load impedance 100 ohms resistive _ .T& lw(96p) | lw(90p) . Nominal pulse shape See pulse mask _ .T& lw(48p) | lw(48p) | lw(90p) , ^ | l | l. Signal level (Note 2) Power at 772 kHz +12 dBm to +19 dBm Power at 1544 kHz { At least 25 dB below the power at 772\ kHz } .TE .LP \fINote\ 1\fR \ \(em\ B8ZS is modified AMI code in which eight consecutive zeros are replaced with 000 | | (em | | (em | if the preceding pulse was positive (+) and with 000 | (em | | | | (em if the preceding pulse was negative (\(em). .LP \fINote\ 2\fR \ \(em\ The signal level is the power level measured in a 3\ kHz bandwidth at the output port for an all 1s pattern transmitted. .nr PS 9 .RT .ad r \fBTableau 4/I.431 [T5.431], p. 9\fR .sp 1P .RT .ad b .RT .sp 1P .LP 4.1.4.3 \fIVoltage of zero\fR .sp 9p .RT .PP The voltage within a time slot containing a zero (space) shall be no greater than either the value produced in that time slot by other pulses (marks) within the mask of Figure\ I\(hy1/I.431 or \(+- | % of the zero\(hyto\(hypeak pulse (mark) amplitude, whichever is greater in magnitude. .RT .sp 1P .LP 4.1.5 \fISpecifications at the input ports\fR .sp 9p .RT .PP The digital signal presented at the input port shall be as defined above but modified by the characteristic of the interconnecting pair. The attenuation of this pair shall be assumed to follow @ sqrt { fIf\fR } @ law and the loss at a frequency of 772\ kHz shall be in the range\ 0 to 6\ dB. .RT .sp 2P .LP 4.2 \fIFrame structure\fR .sp 1P .RT .PP 4.2.1 The frame structure is based on Recommendation G.704, \(sc\(sc\ 3.1.1 and 3.1.2 and is shown in Figure\ 4/I.431. .sp 9p .RT .LP .rs .sp 9P .ad r \fBFigure 4/I.431, (N), p.\fR .sp 1P .RT .ad b .RT .LP .bp .PP 4.2.2 Each frame is 193\ bits long and consists of an F\(hybit followed by 24 consecutive time slots, numbered\ 1 to 24. .sp 9p .RT .PP 4.2.3 Each time slot consists of eight consecutive bits, numbered 1 to\ 8. .sp 9p .RT .PP 4.2.4 The frame repetition rate is 8000 frame/s. .sp 9p .RT .PP 4.2.5 The multi\(hyframe structure is shown in Table\ 5/I.431. Each multi\(hyframe is 24 frames long and is defined by the multi\(hyframe alignment signal (FAS) which is formed by every fourth F\(hybit and has the binary pattern (\ | | | | \ 001011. | | ). .sp 9p .RT .PP 4.2.6 The bits e\d1\uto \d6\uin Table 5/I.431 are used for error checking, as described in \(sc\ 2.1.3.1.2 of Recommendation\ G.704. A valid error check by the receiver is an indication of transmission quality and of the absence of false frame alignment (see \(sc\ 4.6.3 of this Recommendation). .sp 9p .RT .LP .sp 1 .ce \fBH.T. [T6.431]\fR .ce TABLE\ 5/I.431 .ce \fBMulti\(hyframe structure\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(42p) | cw(36p) sw(24p) sw(24p) sw(24p) , ^ | c | c s s ^ | ^ | c | c | c. Multi\(hyframe frame number F\(hyBits Multi\(hyframe bit number Assignments FAS See Note See \(sc\ 4.2.6 _ .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . \ 1 \ \ \ 1 \(em m n .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . \ 2 \ 194 \(em \(em e 1 .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . \ 3 \ 387 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . \ 4 \ 580 0 \(em \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . \ 5 \ 773 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . \ 6 \ 966 \(em \(em e 2 .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . \ 7 1159 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . \ 8 1352 0 \(em \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . \ 9 1545 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 10 1738 \(em \(em e 3 .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 11 1931 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 12 2124 1 \(em \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 13 2317 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 14 2510 \(em \(em e 4 .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 15 2703 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 16 2896 0 \(em \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 17 3089 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 18 3282 \(em \(em e 5 .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 19 3475 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 20 3668 1 \(em \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 21 3861 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 22 4054 \(em \(em e 6 .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 23 4247 \(em m \(em .T& cw(42p) | cw(36p) | cw(24p) | cw(24p) | cw(24p) . 24 4440 1 \(em \(em .TE .LP \fINote\fR \ \(em\ With the exception of \(sc 4.7.3, the use of the m bit is for further study (for example, for maintenance and operational information). .nr PS 9 .RT .ad r \fBTableau 5/I.431 [T6.431], p.\fR .sp 1P .RT .ad b .RT .LP .bp .sp 1P .LP 4.3 \fITiming considerations\fR .sp 9p .RT .PP This section describes the hierarchical synchronization method selected for synchronizing ISDNs. It is based upon consideration of satisfactory customer service, ease of maintenance, administration and minimizing cost. .PP The NT derives its timing from the network clock. The TE synchronizes its timing (bit, octet, framing) from the signal received from the NT and synchronizes accordingly its transmitted signal. .RT .sp 2P .LP 4.4 \fITime slot assignment\fR .sp 1P .RT .sp 1P .LP 4.4.1 \fID\(hychannel\fR .sp 9p .RT .PP Time slot\ 24 is assigned to the D\(hychannel when this channel is present. .RT .sp 1P .LP 4.4.2 \fIB\(hy channel and H\(hychannels\fR .sp 9p .RT .PP A channel occupies an integer number of time slots and the same time slot positions in every frame. A B\(hychannel may be assigned any time slot in the frame, an H\d0\u\(hychannel may be assigned any six slots in the frame, in numerical order (not necessarily consecutive), and an H\d1\\d1\u\(hychannel may be assigned slots\ 1 to 24 in a frame. The assignment may vary on a call by call basis (see Note). Mechanisms for the assignment of these slots for a call are specified in Recommendation\ I.451. .PP \fINote\fR \ \(em\ For an interim period, a fixed time slot allocation to form channels may be required. An example of a fixed assignment of slots for the case where only H\d0\u\(hychannels are present at the interface is given in Annex\ A. .RT .sp 2P .LP 4.5 \fIJitter\fR .sp 1P .RT .sp 1P .LP 4.5.1 \fITiming jitter\fR .sp 9p .RT .PP Timing jitter is specified as follows: .RT .sp 1P .LP 4.5.1.1 \fITolerable jitter at TE input\fR .sp 9p .RT .PP A TE shall tolerate a sinusoidal input jitter according to the amplitude\(hyfrequency characteristic of Figure\ 5/I.431 without producing bit\ errors or losing frame alignment. .RT .LP .rs .sp 19P .ad r \fBFigure 5/I.431, (N), p.\fR .sp 1P .RT .ad b .RT .LP .bp .sp 1P .LP 4.5.1.2 \fITE output jitter\fR .sp 9p .RT .PP With no jitter on the TE input signal that provides timing, jitter at the TE output shall not exceed the following two limitations simultaneously: .RT .LP i) Band\ 1 (10\ Hz\(hy40\ kHz) : 0.5 UI (Unit Interval) peak\(hyto\(hypeak .LP ii) Band\ 2 (8\ kHz\(hy40\ kHz) : 0.07 UI peak\(hyto\(hypeak. .sp 1P .LP 4.5.2 \fIWander\fR .sp 9p .RT .PP Wander is specified for frequencies below 10\ Hz. .RT .sp 1P .LP 4.5.2.1 \fISignal from the network side\fR .sp 9p .RT .PP Wander shall not exceed 5 UI peak\(hyto\(hypeak in any 15 minute interval and shall not exceed 28\ UI peak\(hyto\(hypeak within a period of 24\ hours. .RT .sp 1P .LP 4.5.2.2 \fISignal from the user side\fR .sp 9p .RT .PP Wander shall not exceed 5 UI peak\(hyto\(hypeak in any 15 minute interval and shall not exceed 28\ UI peak\(hyto\(hypeak within a period of 24\ hours. .RT .sp 2P .LP 4.6 \fIInterface procedures\fR .sp 1P .RT .sp 1P .LP 4.6.1 \fICodes for idle channels and idle slots\fR .sp 9p .RT .PP A pattern including at least three binary ONEs in an octet must be transmitted in every time slot that is not assigned to a channel (e.g.\ time slots awaiting channel assignment on a per\(hycall basis, residual slots on an interface that is not fully provisioned,\ etc.), and in every time slot of a channel that is not allocated to a call in both directions. .RT .sp 1P .LP 4.6.2 \fIInterframe (layer 2) time fill\fR .sp 9p .RT .PP Contiguous HDLC flags shall be transmitted on the D\(hychannel when its layer\ 2 has no frames to send. .RT .sp 1P .LP 4.6.3 \fIFrame alignment and CRC\(hy6 procedure\fR .sp 9p .RT .PP The frame alignment and CRC\(hy6 procedures shall be in accordance with Recommendation\ G.706, \(sc\ 2. .RT .sp 2P .LP 4.7 \fIMaintenance\fR .sp 1P .RT .sp 1P .LP 4.7.1 \fIGeneral introduction\fR .sp 9p .RT .PP Recommendation\ I.604 specifies an overall approach to be employed in maintaining ISDN primary rate access. However, since the required maintenance functions may influence the design of terminating pieces of equipment, a brief description of primary rate access maintenance is presented in this Recommendation. .RT .sp 1P .LP 4.7.2 \fIMaintenance functions\fR .sp 9p .RT .PP The interface divides maintenance responsibility between network and user sides. .PP Specified maintenance functions are as follows: .RT .LP a) Supervision of layer\ 1 capability and reporting across the interface, which includes, on the user side, reporting loss of incoming signal or loss of frame alignment from the network side. .LP On the network side, reporting loss of layer\ 1 capability and the incoming signal or frame alignment from the user side, are included. .LP b) CRC performance monitoring and reporting across the interface (this function is specified in \(sc\ 4.7.4.). .LP c) Other maintenance functions are for further study. .bp .sp 1P .LP 4.7.3 \fIDefinition of \fR \fImaintenance signals at the interface\fR .sp 9p .RT .PP The RAI (Remote Alarm Indication) signal indicates loss of layer\ 1 capability at the user\(hynetwork interface. RAI propagates towards the network if layer\ 1 capability is lost in the direction of the user, and RAI propagates toward the user if layer\ 1 capability is lost in the direction of the network. RAI is coded as continuously repeated 16\(hybit sequences of eight\ binary ONEs and eight\ binary ZEROs (1111111100000000) in the m\ bit. [\fINote\fR \ \(em\ HDLC flag patterns (01111110) are transmitted in the m\ bits when no information signal is to be sent.] .PP The AIS (Alarm Indication Signal) is used to indicate loss of layer\ 1 capability in the ET\(hyto\(hyTE direction on the network side of the user\(hynetwork interface. A characteristic of AIS is that its presence indicates that the timing provided to the TE may not be the network clock. AIS is coded as a binary all ONEs, 1544\ kbit/s bit stream. .PP In leased line circuit applications with no D\(hychannel, some channel\(hyassociated layer maintenance messages may need to be transferred across the interface. These maintenance messages would be transported in the m\ bit. Further characteristics of these messages are for further study. .RT .sp 1P .LP 4.7.4 \fICRC\(hy6 in\(hyservice performance monitoring and reporting\fR .sp 9p .RT .PP Messages in the m\ bit that exercise CRC\(hy6 performance monitoring capabilities can be used to sectionalize troubles in the primary rate access. This sectionalization could be accomplished from either the NT or the TE. Characteristics of these maintenance messages are for further study. .RT .sp 2P .LP \fB5\fR \fBInterface at 2048 kbit/s\fR .sp 1P .RT .sp 1P .LP 5.1 \fIElectrical characteristics\fR .sp 9p .RT .PP This interface should conform to Recommendation\ G.703, \(sc\ 6, which recommends the basic electrical characteristics. .PP \fINote\fR \ \(em\ The use of the unbalanced 75\ ohm (coaxial) interface is required by some Administrations in the short\(hyterm. However, the balanced 120\ ohm (symmetric pair) interface is preferred for the ISDN primary rate application. .RT .sp 2P .LP 5.2 \fIFrame structure\fR .sp 1P .RT .sp 1P .LP 5.2.1 \fINumber of bits per time slot\fR .sp 9p .RT .PP Eight, numbered from 1 to 8. .RT .sp 1P .LP 5.2.2 \fINumber of time slots per frame\fR .sp 9p .RT .PP Thirty\(hytwo, numbered from 0 to 31. The number of bits per frame is 256 and the frame repetition rate is 8000\ frame/s. .RT .sp 1P .LP 5.2.3 \fIAssignment of bits in time slot 0\fR .sp 9p .RT .PP The bits of time slot\ 0 are in accordance with Recommendation\ G.704, \(sc\ 2.3.2. The E\ bits are assigned to the CRC error information procedures. .PP S\da\ubits with bit position 4 and 8 are reserved for international standardization and shall be ignored by the TE for the time being. S\da\u\ bits with position\ 5, 6, 7: are reserved for national use. The terminals not making use of these bits shall ignore any received pattern. .RT .sp 2P .LP 5.2.4 \fITime slot assignment\fR .sp 1P .RT .sp 1P .LP 5.2.4.1 \fIFrame alignment signal\fR .sp 9p .RT .PP Time slot\ 0 provides for frame alignment in accordance with \(sc\ 5.2.3. .RT .sp 1P .LP 5.2.4.2 \fID\(hychannel\fR .sp 9p .RT .PP Time slot\ 16 is assigned to the D\(hychannel when this channel is present. The assignment of time slot\ 16 when not used for a D\(hychannel is for further study. .bp .RT .sp 1P .LP 5.2.4.3 \fIB\(hychannel and H\(hychannels\fR .sp 9p .RT .PP A channel occupies an integer number of time slots and the same time slot positions in every frame. .PP A B\(hychannel may be assigned any time slot in the frame and an H\d0\u\(hychannel may be assigned any six slots, in numerical order, not necessarily consecutive (Note\ 1). .PP The assignment may vary on a call\(hyby\(hycall basis (Note 2). Mechanisms for the assignment of these slots for a call are specified in Recommendation\ I.451. .PP An \d1\\d2\u\(hychannel shall be assigned time slots 1 to 15 and 17 to 31 in a frame and an H\d1\\d1\u\(hychannel may be assigned time slots as in the example given in Annex\ B. .PP \fINote 1\fR \ \(em\ In any case, time slot\ 16 should be kept free for D\(hychannel utilization. .PP \fINote 2\fR \ \(em\ For an interim period, a fixed time slot allocation to form channels may be required. Examples of a fixed assignment of slots for the case where only H\d0\u\(hychannels are present at the interface are given in Annex\ A. .RT .sp 1P .LP 5.2.4.4 \fIBit sequence independence\fR .sp 9p .RT .PP Time slots\ 1 to 31 provide bit sequence independent transmission. .RT .sp 1P .LP 5.3 \fITiming considerations\fR .sp 9p .RT .PP The NT derives its timing from the network clock. The TE synchronizes its timing (bit, octet, framing) from the signal received from the NT and synchronizes accordingly the transmitted signal. .PP In an unsynchronized condition (e.g. when the access that normally provides network timing is unavailable) the frequency deviation of the free\(hyrunning clock shall not exceed\ \(+- | 0\ ppm. .RT .sp 2P .LP 5.4 \fIJitter\fR .sp 1P .RT .sp 1P .LP 5.4.1 \fIGeneral considerations\fR .sp 9p .RT .PP The jitter specifications take into account subscriber configurations with only one access and configurations with multiple accesses. .PP In the case of one access only, this may be to a network with transmission systems of either high\ Q or low\ Q clock recovery circuits . .PP In the case of multiple accesses, all access transmission systems may be of the same kind (either low\ Q or high\ Q clock recovery circuits) or they may be of different kinds (some with high Q and some with low Q\ clock recovery circuit). .PP Examples of single and multiple accesses are given in Figure\ 6/I.431. .PP The reference signal for the jitter measurement is derived from the network clock. The nominal value for one\ UI is 488\ ns. .RT .LP .rs .sp 12P .ad r \fBFigure 6/I.431, (N), p.\fR .sp 1P .RT .ad b .RT .LP .bp .sp 1P .LP 5.4.2 \fIMinimum tolerance to jitter and wander at TE inputs\fR .sp 9p .RT .PP The 2048\ kbit/s inputs of a TE shall tolerate sinusoidal input jitter/wander in accordance with Figure\ 7/I.431 without producing bit errors or losing frame alignment. .RT .LP .sp 1 .ce \fBH.T. [T7.431]\fR .ce \fBMONTAGE:\fR .ce \ Figure\ 7/I.431 \*`a coller .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(33p) | cw(27p) | cw(27p) | cw(27p) | cw(33p) | cw(27p) | cw(27p) | cw(27p) . A 0 A 1 A 2 f 0 f 1 f 2 f 3 f 4 _ .T& cw(33p) | cw(27p) | cw(27p) | cw(27p) | cw(33p) | cw(27p) | cw(27p) | cw(27p) . 20.5 UI (Note 1) 1.0 UI (Note 2) 0.2 UI 12\(mu10\uD\dlF261\u6\d Hz 20 Hz 3.6 kHz 18 kHz 100 kHz .TE .LP \fINote\ 1\fR \ \(em\ A 0 represents Maximum Relative Time Interval Error (MRTIE) as defined in Recommendation\ G.812, i.e. a phase difference between the synchronizing input and the input being considered. .LP \fINote\ 2\fR \ \(em\ With TEs for multiple access (e.g. when an access is connected to a long leased circuit leading to a distant PABX), a jitter tolerance of 1.5\ UI (with a corresponding f 2 at 2.4\ kHz) may be required. .LP FIGURE\ 7/I.431 \fBMinimum tolerable jitter and wander at the TE input\fR .RT .ad r \fBFigure 7/I.431 (avec une partie comme tableau) [T7.431], p.\fR .sp 1P .RT .ad b .RT .LP .sp 1 .sp 1P .LP 5.4.3 \fITE and NT2 output jitter\fR .sp 9p .RT .PP Two cases must be considered: .RT .sp 1P .LP 5.4.3.1 \fITE and NT2 with only one user\(hynetwork interface\fR .sp 9p .RT .PP a) With no jitter at the input supplying timing or in the free\(hyrunning mode, the TE output jitter shall be in accordance with Table\ 6/I.431. .RT .LP b) With jitter present at the input supplying timing, the output jitter is the sum of the intrinsic jitter of the TE plus the input jitter multiplied by the jitter transfer characteristics. .bp .LP The jitter transfer characteristics shall conform to Figure\ 8/I.431. .ce \fBH.T. [T8.431]\fR .ce TABLE\ 6/I.431 .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(48p) sw(48p) | cw(48p) , c | c | ^ . Measurement filter bandwidth { Output jitter: (UI peak\(hyto\(hypeak) } Lower cutoff Upper cutoff _ .T& cw(48p) | cw(48p) | cw(48p) . \ 20 Hz 100 kHz \(= 0.125 .T& cw(48p) | cw(48p) | cw(48p) . 700 Hz 100 Hz\fBk\fR \(= 0.12\ _ .TE .nr PS 9 .RT .ad r \fBTableau 6/I.431 [T8.431], p.\fR .sp 1P .RT .ad b .RT .ce \fBH.T. [T9.431]\fR .ce \fBMONTAGE:\fR .ce \ Figure\ 8/I.431 \*`a coller .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) . Y X f a f b f c f d _ .T& cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) | cw(24p) . \(em19.5 dB 0.5 dB 10 Hz 40 Hz 400 Hz { 100 kHz FIGURE\ 8/I.431 \fBJitter transfer characteristics\fR } _ .TE .nr PS 9 .RT .ad r \fBFigure 8/I.431 (avec une partie comme tableau) [T9.431], p.\fR .sp 1P .RT .ad b .RT .sp 1P .LP 5.4.3.2 \fITE with more than one user\(hynetwork interface to the same\fR \fInetwork\fR .sp 9p .RT .PP a) With no jitter at the input (or inputs) supplying timing or in the free running mode see \(sc\ 5.4.3.1\ a). .RT .LP b) In the multiple access case the output jitter depends on: .LP \(em the input jitter of each access; .LP \(em the transfer characteristic; .LP \(em the timing extraction and distribution concept; .bp .LP \(em the future growth of the TE. Since the timing extraction and distribution concept of the TE is outside of the scope of this Recommendation, the output jitter at each individual individual access can be controlled only by the definition of the appropriate jitter transfer characteristic in the TE. .LP In order to restrict the output jitter to tolerable values and to simplify testing, the jitter transfer characteristic between any receiver and its associated transmitter shall be tested to the transfer characteristic given in Figure\ 8/I.431 and the following parameters: .LP .sp 1 .ce \fBH.T. [T10.431]\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) . Y X f a f b f c f d _ .T& cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) . \(em19.8 dB 0.2 dB not to be defined 0.1 Hz 1 Hz 100 Hz _ .TE .nr PS 9 .RT .ad r \fBTable de la fin du point 5.4.3.2 [T10.431], p.\fR .sp 1P .RT .ad b .RT .LP .sp 1 .sp 1P .LP 5.5 \fITolerable \fR \fIlongitudinal voltage\fR .sp 9p .RT .PP For minimum tolerance to longitudinal voltage at input ports, the receiver shall operate without errors with any valid input signal in the presence of a longitudinal voltage\ \fIV\fR\d\fIL\fR\u. .PP \fIV\fR\d\fIL\fR\u= 2 Vrms over the frequency range 10\ Hz to 30\ MHz. .PP The test configuration is given in Figure 9/I.431. .RT .LP .rs .sp 25P .ad r \fBFigure 9/I.431, (N), p.\fR .sp 1P .RT .ad b .RT .LP .bp .sp 1P .LP 5.6 \fIOutput signal balance\fR .sp 9p .RT .PP Output signal balance, which is measured in accordance with Recommendation\ O.9, \(sc\ 2.7, shall meet the following requirements: .RT .LP a) \fIf\fR \ =\ 1\ MHz:\ \(>="\ 40\ dB .LP \fI\fR b) 1\ MHz\ <\ \fIf\fR \ \(=\ 30\ MHz: minimum value decreasing from 40\ dB at 20\ dB/decade. .sp 1P .LP 5.7 \fIImpedance towards ground\fR .sp 9p .RT .PP The impedance towards ground of both the receiver input and the transmitter output shall meet the following requirements: \v'6p' .RT .sp 1P .ce 1000 10\ Hz\ <\ \fIf\fR \ \(=\ 1\ MHz:\ >\ 1000\ ohm .ce 0 .sp 1P .PP .sp 1 This requirement is met if the test according to Figure\ 10/I.431 results in a voltage\ \fIV\fR \dTest \u\ \(=\ 20\ mV\ rms. .LP .rs .sp 18P .ad r \fBFigure 10/I.431, (N), p.\fR .sp 1P .RT .ad b .RT .sp 2P .LP 5.8 \fIInterface procedures\fR .sp 1P .RT .sp 1P .LP 5.8.1 \fICodes for idle channels and idle slots\fR .sp 9p .RT .PP A pattern including at least three binary ONEs in an octet must be transmitted in every time slot that is not assigned to a channel (e.g. time slots awaiting channel assignment on a per\(hycall basis, residual slots on an interface that is not fully provisioned,\ etc.), and in every time slot of a channel that is not allocated to a call in both directions. .RT .sp 1P .LP 5.8.2 \fIInterframe (layer 2) time fill\fR .sp 9p .RT .PP Contiguous HDLC flags will be transmitted on the D\(hychannel when its layer\ 2 has no frames to send. .RT .sp 1P .LP 5.8.3 \fIFrame alignment and CRC\(hy4 procedures\fR .sp 9p .RT .PP The frame alignment and CRC procedures shall be in accordance with Recommendation\ G.706, \(sc\ 4. .bp .RT .sp 1P .LP 5.9 \fIMaintenance at the interface\fR .sp 9p .RT .PP The network reference configuration for the maintenance activities on primary rate subscriber access is given in Recommendation\ I.604. .PP The associated maintenance procedure, which is described there, needs a continuous supervision procedure on layer\ 1 for the automatic fault detection, automatic failure confirmation and information. .PP \fINote\fR \ \(em\ The terms \fIanomaly\fR , \fIdefect\fR , \fIfault\fR | and \fIfailure\fR | are defined in Recommendation\ M.20. .RT .sp 1P .LP 5.9.1 \fIDefinitions of maintenance signals\fR .sp 9p .RT .PP The RAI (Remote Alarm Indication) signal indicates loss of layer\ 1 capability at the user\(hynetwork interface. RAI propagates towards the network if layer\ 1 capability is lost in the direction of the user, and RAI propagates toward the user if layer\ 1 capability is lost in the direction of the network. RAI is coded in bit\ A , i.e. bit\ 3 of time slot\ 0 of the operational frame which does not contain the frame alignment signal (see Table 4b/G.704): .PP RAI present: A\(hybit set to 1 .PP RAI not present: A\(hybit set to 0. .PP The AIS (Alarm Indication Signal) is used to indicate loss of layer\ 1 capability in the ET\(hyto\(hyTE direction on the network side of the user\(hynetwork interface. A characteristic of AIS is that its presence indicates that the timing provided to the TE may not be the network clock. AIS is coded as a binary all ONEs, 2048\ kbit/s bit stream. .PP CRC error report: E\ bit (see Table 4b/G.704) in operational frames. .RT .sp 2P .LP 5.9.2 \fIUse of CRC procedure\fR .sp 1P .RT .sp 1P .LP 5.9.2.1 \fIIntroduction\fR .sp 9p .RT .PP At the user\(hynetwork interface the CRC procedure according to Recommendations\ G.704 and G.706 is applied to gain security in frame alignment and detect block errors. The CRC error information uses the E\ bits as defined in Table\ 4b/G.704. The coding is E\ =\ \*Q0\*U for a block with failure and E\ =\ \*Q1\*U for a block without failure. With respect to CRC error information to the other side of the interface and processing of this information, two different options exist, one has CRC processing in the transmission link and the other not. .PP The use of the CRC procedure at the user\(hynetwork interface implies: .RT .LP i) that the user side shall generate towards the interface a 2048\ kbit/s frame with associated CRC bits; .LP ii) that the network side shall generate towards the interface a 2048\ kbit/s frame with associated CRC bits; .LP iii) that the user side shall monitor the CRC bits associated with the received frames (CRC codes calculation and comparison with received CRC codes); .LP iv) that the user side shall detect the CRC blocks received with error; .LP v) that the user side shall generate the CRC error information according to the CRC procedure; .LP vi) that the network side shall monitor the CRC bits associated with the received frames; .LP vii) that the network side shall detect the CRC blocks received with error; .LP viii) that the network side shall generate the CRC error information according to the CRC procedure; .LP ix) that the network side shall detect the CRC error information and process all the received information in accordance with Recommendation\ I.604. .sp 2P .LP 5.9.2.2 \fILocalization of the CRC functions in the subscriber access\fR \fIfrom the user point of view\fR .sp 1P .RT .sp 1P .LP 5.9.2.2.1 \fINo CRC processing in the transmission link\fR .sp 9p .RT .PP Figure\ 11/I.431 gives the locations of the CRC function processes in a subscriber access when there is no CRC processing in the transmission link. .bp .RT .LP .rs .sp 21P .ad r \fBFigure 11/I.431, (N), p.\fR .sp 1P .RT .ad b .RT .sp 1P .LP 5.9.2.2.2 \fICRC processing in the digital transmission link\fR .sp 9p .RT .PP Figure\ 12/I.431 gives the locations of CRC function processes in a subscriber access, with CRC processing in the NT. .RT .LP .rs .sp 23P .ad r \fBFigure 12/I.431, (N), p.\fR .sp 1P .RT .ad b .RT .LP .bp .sp 2P .LP 5.9.3 \fIMaintenance functions\fR .sp 1P .RT .sp 1P .LP 5.9.3.1 \fIGeneral requirements\fR .sp 9p .RT .PP The equipments located on the user side and on the network side of the interface shall: .RT .LP \(em detect the anomalies; .LP \(em detect the defects; .LP \(em take actions for reporting the detected anomalies and defects (defect indication signals AIS, RAI); .LP \fR \(em detect the received defect indication signals. .sp 2P .LP 5.9.3.2 \fIMaintenance functions on the user side\fR .sp 1P .RT .sp 1P .LP 5.9.3.2.1 \fIAnomalies and defect detection\fR .sp 9p .RT .PP The user side shall detect the following defects or anomalies: .RT .LP \(em loss of power on the user side; .LP \(em loss of incoming signal at interface (see Note); .LP \(em loss of frame alignment (see Recommendation\ G.706); .LP \(em CRC error. .PP \fINote\fR \ \(em\ The detection of this defect is required only when it has not the effect of a loss of frame alignment indication. .sp 1P .LP 5.9.3.2.2 \fIDetection of defect indication signals\fR .sp 9p .RT .PP The following defect indications received at interface shall be detected by the user side: .RT .LP \(em remote alarm indication (RAI) (Note); .LP \(em alarm indication signal (AIS). .PP \fINote\fR \ \(em\ The RAI signal is used to indicate loss of layer\ 1 capability. It may be used to indicate: .LP \(em loss of signal or loss of framing; .LP \(em excessive CRC errors (optional); .LP \(em loopbacks applied in the network. .PP The conditions of excessive CRC errors are outside the scope of this Recommendation. .sp 1P .LP 5.9.3.2.3 \fIConsequent actions\fR .sp 9p .RT .PP Table\ 7/I.431 gives the actions that the user side (TE function) has to take after the detection of a defect or of a defect indication signal. .PP \fINote\ 1\fR \ \(em\ When the defect conditions have disappeared or when the defect indication signals are no longer received, the defect indications AIS and RAI must disappear as soon as possible. .PP \fINote\ 2\fR \ \(em\ The following points are required to ensure that an equipment is not removed from service due to short breaks in transmission: .RT .LP i) The persistence of an RAI or of an AIS shall be verified for at least 100\ ms before action is taken; .LP ii) When an RAI or an AIS disappears, action shall be taken immediately. .sp 2P .LP 5.9.3.3 \fIMaintenance functions on the network side\fR .sp 1P .RT .sp 1P .LP 5.9.3.3.1 \fIDefect detection\fR .sp 9p .RT .PP All the following defect conditions shall be detected by the network side of the T\ interface (NT1, LT, ET functions) (see Note\ 2): .RT .LP \(em loss of power on the network side; .LP \(em loss of incoming signal; .LP \(em loss of frame alignment (see Recommendation\ G.706); .LP \fR \(em CRC error. .bp .PP \fINote\ 1\fR \ \(em\ The equipment of the primary rate digital link (NT1, LT,\ etc.) have to detect loss of incoming signal and then to generate downstream towards the interface the fault indication signal AIS. .PP \fINote\ 2\fR \ \(em\ Some equipment in the network may detect only part of the defects or fault conditions listed above. .RT .LP .sp 2 .ce \fBH.T. [T11.431]\fR .ce TABLE\ 7/I.431 .ce \fBDefect conditions and defect indication signals detected\fR .ce \fBby the user side and consequent actions\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(60p) | cw(48p) sw(48p) , ^ | c s ^ | c | c. { Defect conditions and defect indication signals detected by the user side } Consequent actions { Defect indications at the interface } Generation of RAI { Generation of CRC error information (see Note 4) } _ .T& lw(60p) | cw(48p) | cw(48p) . Loss of power on user side Not applicable Not applicable _ .T& lw(60p) | cw(48p) | cw(48p) . Loss of signal Yes Yes (Note 1) _ .T& lw(60p) | cw(48p) | cw(48p) . Loss of frame alignment Yes No (Note 2) _ .T& lw(60p) | cw(48p) | cw(48p) . Reception of RAI No No _ .T& lw(60p) | cw(48p) | cw(48p) . Reception of AIS Yes No (Note 3) _ .T& lw(60p) | cw(48p) | cw(48p) . { Detection by NT2 of CRC errors } No Yes .TE .LP \fINote\ 1\fR \ \(em\ Only when loss of frame alignment has not yet occurred. .LP \fINote\ 2\fR \ \(em\ The loss of frame alignment inhibits the process associated with the CRC procedure. .LP \fINote\ 3\fR \ \(em\ The AIS signal is detected only after the fault \*Qloss of frame alignment\*U, thus the process associated with the CRC procedure is inhibited. .LP \fINote\ 4\fR \ \(em\ If CRC errors are detected in frames carrying the RAI signal, then CRC error reports should be generated. .nr PS 9 .RT .ad r \fBTableau 7/I.431 [T11.431], p. 22\fR .sp 1P .RT .ad b .RT .sp 1P .LP .sp 2 5.9.3.3.2 \fIDetection of defect indication signals\fR .sp 9p .RT .PP The following defect indications received at interface shall be detected by the network side: .RT .LP \(em remote alarm indication (RAI); .LP \(em CRC error information. .bp .sp 1P .LP 5.9.3.3.3 \fIConsequent actions\fR .sp 9p .RT .PP Table\ 8/I.431 gives the actions that the network side (NT1, ET functions) has to take after defect detection or defect indication detection. .PP \fINote\ 1\fR \ \(em\ When the defect conditions have disappeared or the defect indication signals are no longer received, the defect indication signals AIS and RAI should disappear as soon as possible. .PP \fINote\ 2\fR \ \(em\ The following points are required to ensure that an equipment is not removed from service due to short breaks in transmission: .RT .LP i) the persistence of an RAI or of an AIS shall be verified for at least 100\ ms before action is taken; .LP ii) when an RAI or an AIS disappears, action shall be taken immediately. .LP .sp 1 .ce \fBH.T. [T12.431]\fR .ce TABLE\ 8/I.431 .ce \fBDefect conditions and defect indication signals detected by\fR .ce .ce \fBthe network side of interface, and consequent actions\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(72p) | cw(48p) sw(48p) sw(48p) , ^ | c s s ^ | c | c | c. { Defect conditions and defect signal indications detected by network side } Consequent actions { Defect indications at interface } Generation of RAI Generation of AIS { Generation of CRC error information } _ .T& lw(72p) | cw(48p) | cw(48p) | cw(48p) . Loss of power on network side Not applicable Yes, if possible Not applicable _ .T& lw(72p) | cw(48p) | cw(48p) | cw(48p) . Loss of signal Yes No Yes (Note 1) _ .T& lw(72p) | cw(48p) | cw(48p) | cw(48p) . Loss of frame alignment Yes No { Option 1: No Option 2: Yes (Note 3) } _ .T& lw(72p) | cw(48p) | cw(48p) | cw(48p) . { Detection of defect in the network\(hyto\(hyuser direction } No Yes No _ .T& lw(72p) | cw(48p) | cw(48p) | cw(48p) . Reception of RAI No No No (Note 2) _ .T& lw(72p) | cw(48p) | cw(48p) | cw(48p) . { Detection of defect in the user\(hyto\(hynetwork direction up to ET } Yes No No _ .T& lw(72p) | cw(48p) | cw(48p) | cw(48p) . Detection of CRC errors No No Yes _ .T& lw(72p) | cw(48p) | cw(48p) | cw(48p) . { Reception of CRC error information } No No No _ .T& lw(72p) | cw(48p) | cw(48p) | cw(48p) . Excessive CRC error ratio Yes (Optional) No Not applicable .TE .LP \fINote\ 1\fR \ \(em\ Only when loss of frame alignment has not yet occurred. .LP \fINote\ 2\fR \ \(em\ If CRC errors are detected in frames carrying the RAI signal, then CRC error reports shall be generated. .LP \fINote\ 3\fR \ \(em\ See CCITT Recommandation I.604. .nr PS 9 .RT .ad r \fBTableau 8/I.431 [T12.431], p.\fR .sp 1P .RT .ad b .RT .LP .bp .sp 2P .LP \fB6\fR \fBConnector\fR .sp 1P .RT .PP Interface connectors and contact assignments are the subject of ISO and IEC standards. However, permanent wiring connections of TEs to NTs are also permitted. .RT .sp 2P .LP \fB7\fR \fBInterface wiring\fR .sp 1P .RT .PP In case of symmetrical wiring, the magnitude of the characteristic impedance of the interface cables shall be 120\ ohm \(+- 20% in a frequency range 200\ kHz to 1\ MHz and 120\ ohm \(+- | 0% at 1\ MHz. .PP For coaxial interfaces, the magnitude of the characteristic impedance of the interface cables shall be 75\ ohm (\(+- | % at 1024\ kHz). .RT .sp 2P .LP \fB8\fR \fBPower feeding\fR .sp 1P .RT .sp 1P .LP 8.1 \fIProvision of power\fR .sp 9p .RT .PP The provision of power to the NT via the user network interface using a separate pair of wires from those used for transmission, is optional. .RT .sp 1P .LP 8.2 \fIPower available at the NT\fR .sp 9p .RT .PP The power available at the NT via the user\(hynetwork interface, when provided, shall be at least 7\ watts. .RT .sp 1P .LP 8.3 \fIFeeding voltage\fR .sp 9p .RT .PP The feeding voltage for the NT shall be in the range of \(em32 to \(em57\ volts. .PP The polarity of the voltage towards ground shall be negative. .RT .sp 1P .LP 8.4 \fISafety requirements\fR .sp 9p .RT .PP In principle, safety requirements are outside the scope of this Recommendation. However, in order to harmonize power source requirements the following information is provided: .RT .LP i) the voltage source and the feeding interface should be protected against short circuit or overload. The specific requirements are for further study; .LP ii) the power input of NT1 shall not be damaged by an interchange of wires. .PP With respect to the feeding interface of the power source, which is regarded as a touchable part in the sense of IEC\ Publication\ 950, the protection methods against electric shock specified in IEC\ Publication\ 950 may be applied. .ce 1000 ANNEX\ A .ce 0 .ce 1000 (to Recommendation I.431) .sp 9p .RT .ce 0 .ce 1000 \fBTime slot assignment for interfaces \fBhaving only H\fR\(da\fB0\(hychannels\fR .sp 1P .RT .ce 0 .PP The following are examples of fixed assignment of time slots when only H\d0\u\(hychannels are present at the interface. .sp 1P .RT .sp 1P .LP A.1 \fI1544\ kbit/s interface\fR .sp 9p .RT .ce \fBH.T. [T13.431]\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(60p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) . H 0\(hychannel a b c d _ .T& lw(60p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) . Time slots used 1 to 6 7 to 12 13 to 18 19 to 24 | ua\d\u)\d .TE .LP \ua\d\u)\d This fourth H 0\(hychannel is available if time slot 24 is not used for a D\(hychannel. .nr PS 9 .RT .ad r \fBTableau [T13.431], p.\fR .sp 1P .RT .ad b .RT .LP .bp .sp 1P .LP A.2 \fI2048 kbit/s interface\fR .sp 9p .RT .ce \fBH.T. [T14.431]\fR .ce \fIExample 1\fR .ce .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(60p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) . H 0\(hychannel a b c d e _ .T& lw(60p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) . Time slots used 1\(hy2\(hy3 17\(hy18\(hy19 4\(hy5\(hy6 20\(hy21\(hy22 7\(hy8\(hy9 23\(hy24\(hy25 { 10\(hy11\(hy12 26\(hy27\(hy28 } { 13\(hy14\(hy15 29\(hy30\(hy31 } _ .TE .nr PS 9 .RT .ad r \fBTableau [T14.431], p.\fR .sp 1P .RT .ad b .RT .LP .sp 3 .ce 1000 ANNEX\ B .ce 0 .ce 1000 (to Recommendation\ I.431) .sp 9p .RT .ce 0 .ce 1000 \fBTime slot assignment for 2048 kbit/s interfaces having an H\fR\(da\fB1\fR\(da\fB1\(hychannel\fR .sp 1P .RT .ce 0 .PP The following is an example of fixed assignment of times slots when an H\d1\\d1\u\(hychannel is present at the interface. .sp 1P .RT .LP .sp 3 .ce \fBH.T. [T15.431]\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(60p) | cw(30p) | cw(30p) . H 1 1\(hychannel 1\(hy15 16\(hy24 _ .T& lw(60p) | cw(30p) | cw(30p) . Time slots used 1\(hy15 17\(hy25 .TE .LP \fINote\fR \ \(em\ Time slot 16 is to be assigned to the D\(hychannel, when this channel is present. Time slots 26 to 31 may be used for an H 0\(hychannel or six B\(hychannels. .nr PS 9 .RT .ad r \fBTableau [T15.431], p.\fR .sp 1P .RT .ad b .RT .LP .bp .ce 1000 APPENDIX\ I .ce 0 .ce 1000 (to Recommendation I.431) .sp 9p .RT .ce 0 .ce 1000 \fBPulse mask for interface at 1544 kbit/s\fR .sp 1P .RT .ce 0 .PP An isolated pulse, when scaled by a constant factor, shall fit the pulse mask shown in Figure\ I\(hy1/I.431. .sp 1P .RT .ce \fBH.T. [T16.431]\fR .ce \fBMONTAGE:\ \fR .ce FIGURE\ I\(hy1/I.431 \*`a coller .ce Corner points for upper curve .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; rw(36p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) . ns \(em500 \(em250 \(em175 \(em175 \(em75 0,0 175 225 600 750 .T& lw(36p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) . Time .T& rw(36p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) . UI \(em0.77 \(em0.39 \(em0.27 \(em0.27 \(em0.12 0.0 0.27 0.35 0.93 1.16 _ .T& lw(36p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) | rw(14p) | rw(14p) | rw(20p) . Amplitude 0.05 0.05 0.80 1.15 1.15 1.05 1.05 \(em0.07 0.05 0.05 _ .TE .nr PS 9 .RT .ad r \fBFigure I\(hy1/I.431 (avec une partie comme tableau) [T16.431], p. 27\fR .sp 1P .RT .ad b .RT .LP .bp .LP \fBMONTAGE : PAGE 270 = PAGE BLANCHE\fR .sp 1P .RT .LP .bp .sp 1P .ce 1000 \v'3P' SECTION\ 4 .ce 0 .sp 1P .ce 1000 \fBISDN\ USER\(hyNETWORK\ INTERFACES:\fR .ce 0 .sp 1P .ce 1000 \fBLAYER\ 2\ RECOMMENDATIONS\fR .ce 0 .sp 1P .sp 2P .LP \fBRecommendation\ I.440\fR .RT .sp 2P .sp 1P .ce 1000 \fBISDN\ USER\(hyNETWORK\ INTERFACE\ DATA\ LINK\ LAYER\ \(em | GENERAL\ ASPECTS\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.440'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.440 %' .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP See Recommendation Q.920, Volume VI, Fascicle VI.10. .sp 1P .RT .sp 2P .LP \fBRecommendation\ I.441\fR .RT .sp 2P .sp 1P .ce 1000 \fBISDN\ USER\(hyNETWORK\ INTERFACE,\ DATA\ LINK\ LAYER\ SPECIFICATION\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.441'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.441 %' .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP See Recommendation Q.921, Volume VI, Fascicle VI.10. .sp 1P .RT .LP .rs .sp 17P .ad r Blanc .ad b .RT .LP .bp .LP \fBMONTAGE : PAGE 272 = PAGE BLANCHE\fR .sp 1P .RT .LP .bp .sp 1P .ce 1000 \v'3P' SECTION\ 5 .ce 0 .sp 1P .ce 1000 \fBISDN\ USER\(hyNETWORK\ INTERFACES:\fR .ce 0 .sp 1P .ce 1000 \fBLAYER\ 3\ RECOMMENDATIONS\fR .ce 0 .sp 1P .sp 2P .LP \fBRecommendation\ I.450\fR .RT .sp 2P .sp 1P .ce 1000 \fBISDN\ USER\(hyNETWORK\ INTERFACE\ LAYER\ 3\ \(em\ GENERAL\ ASPECTS\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.450'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.450 %' .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP See Recommendation Q.930, Volume VI, Fascicle VI.11. \v'1P' .sp 1P .RT .sp 2P .LP \fBRecommendation\ I.451\fR .RT .sp 2P .sp 1P .ce 1000 \fBISDN\ USER\(hyNETWORK\ INTERFACE\ LAYER\ 3\ SPECIFICATION | FOR\ BASIC\ CALL\ CONTROL\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.451'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.451 %' .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP See Recommendation Q.931, Volume VI, Fascicle VI.11. \v'1P' .sp 1P .RT .sp 2P .LP \fBRecommendation\ I.452\fR .RT .sp 2P .sp 1P .ce 1000 \fBGENERIC\ PROCEDURES\ FOR\ THE\ CONTROL\ OF\ ISDN\ SUPPLEMENTARY\ SERVICES\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.452'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.452 %' .ce 0 .sp 1P .ce 1000 \fI(Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP See Recommendation Q.932, Volume VI, Fascicle VI.11. .sp 1P .RT .LP .bp .LP \fBMONTAGE : PAGE 274 = PAGE BLANCHE\fR .sp 1P .RT .LP .bp .sp 1P .ce 1000 \v'3P' SECTION\ 6 .ce 0 .sp 1P .ce 1000 \fBMULTIPLEXING,\ RATE\ ADAPTION\ AND\ SUPPORT\ OF | EXISTING\ INTERFACES\fR .ce 0 .sp 1P .sp 2P .LP \fBRecommendation\ I.460\fR .RT .sp 2P .sp 1P .ce 1000 \fBMULTIPLEXING,\ RATE\ ADAPTION\ AND\ SUPPORT\ OF | EXISTING\ INTERFACES\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.460'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.460 %' .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP This Recommendation describes procedures to be used to: .sp 1P .RT .LP a) adapt the rate of one stream, of rate lower than 64\ kbit/s, into a 64\ kbit/s B\(hychannel; .LP b) multiplex several streams, of rates lower than 64\ kbit/s, into a 64\ kbit/s B\(hychannel. .PP The rates lower than 64\ kbit/s are of two types: .LP 1) binary rates of\ 8, 16 and\ 32\ kbit/s; and .LP 2) other rates including those associated with DTEs conforming to the X\ and V\ series Recommendations. .PP The detailed procedures for support of X\(hySeries circuit mode DTEs, X\(hySeries packet mode DTEs, and V\(hySeries DTEs are given in Recommendations\ I.461 (X.30), I.462 (X.31), I.463 (V.110) and I.465 (V.120), respectively. .PP Rate adaption, multiplexing and support of existing interfaces for restricted 64\ kbit/s transfer capability is covered in Recommendation\ I.464. .RT .sp 2P .LP \fB1\fR \fBRate adaption to a 64 kbit/s channel\fR .sp 1P .RT .sp 1P .LP 1.1 \fIRate adaption of 8, 16 and 32 kbit/s streams\fR .sp 9p .RT .PP The procedure in this section will be used to adapt the rate of a \fIsingle\fR | tream at 8, 16 or 32\ kbit/s into a 64\ kbit/s B\(hychannel. In this Recommendation, bit positions in the B\(hychannel octet are assumed to be numbered from\ 1 to\ 8 with bit position\ 1 being the first transmitted. .PP The procedure requires that: .RT .LP i) the 8 kbit/s stream occupies bit position 1; .LP the 16 kbit/s stream occupies bit positions (1, 2); .LP the 32 kbit/s stream occupies bit positions (1, 2, 3, 4); .LP ii) the order of transmission of the bits of the subrate stream is identical before and after rate adaption; and .LP iii) all unused bit positions be set to binary \*Q1\*U. .sp 1P .LP 1.2 \fIRate adaption of streams other than 8, 16 and 32 kbit/s\fR .sp 9p .RT .PP Information streams at bit rates less than 64\ kbit/s need to be rate adapted to be carried on the B\(hychannel. The approaches in this section are for adapting \fIsingle\fR | nformation streams. .bp .RT .PP 1.2.1 The rate adaption of bit rates up to 32\ kbit/s uses a multi\(hystage approach. One stage is described in Recommendations\ I.461 (X.30), I.462 (X.31), I.463 (V.110). For example, user rates of 4.8\ kbit/s and below are mapped to 8\ kbit/s, 9.6\ kbit/s is mapped to 16\ kbit/s, and 19.2\ kbit/s is mapped to 32\ kbit/s. .sp 9p .RT .PP Another stage of rate adaption is from 8\ kbit/s, 16\ kbit/s, or 32\ kbit/s to 64\ kbit/s and is described in\ \(sc\ 1.1. .PP A third stage for asynchronous data is described in Recommendation\ I.463 (V.110). .RT .PP 1.2.2 Rate adaption of bit rates higher than 32\ kbit/s uses a single stage approach as described in Recommendations\ I.461 (X.30) and I.463 (V.110). That is, 48\ kbit/s and 56\ kbit/s rates are adapted to 64\ kbit/s in one stage. .sp 9p .RT .PP 1.2.3 Rate adaption for packet mode operation may be performed in two ways as described in Recommendation\ I.462 (X.31): .sp 9p .RT .LP a) the preferred method: in using HDLC flag stuffing between HDLC frames; or .LP b) using the two stage approach. .PP 1.2.4 Rate adaption of bit rates up to 48 kbit/s on a B\(hychannel may be performed by insertion of HDLC frames as described in Recommendation\ I.465 (V.120). .sp 9p .RT .sp 2P .LP \fB2\fR \fBMultiplexing into a 64\ kbit/s channel\fR .sp 1P .RT .sp 1P .LP 2.1 \fITime division multiplexing of 8, 16 and 32 kbit/s\fR .sp 9p .RT .PP Multiplexing of 8, 16 and 32\ kbit/s streams is done by interleaving the subrate streams within each B\(hychannel octet. .PP Using the procedures described in \(sc\ 2.1.2, any number of 8, 16 and 32\ kbit/s streams may be combined up to the limit of 64\ kbit/s aggregate bit\(hyrate in one B\(hychannel. .PP Using the procedure described in \(sc\ 2.1.1 can lead to situations where the full 64\ kbit/s capacity cannot be utilized; however, this will not occur if the mixture of substreams is known in advance. The procedures in \(sc\ 2.1.2 are recommended when the mixture will change during the duration of the 64\ kbit/s connection. .RT .sp 1P .LP 2.1.1 \fIFixed format multiplexing\fR .sp 9p .RT .PP This procedure will multiplex any combination of 8, 16 and 32\ kbit/s streams by allocating bit positions in each B\ channel octet to each subrate stream. The fixed format procedure requires that: .RT .LP i) an 8 kbit/s stream be allowed to occupy any bit position; a 16\ kbit/s stream occupies bit positions (1,\ 2) or (3,\ 4) or (5,\ 6) or (7,\ 8); a 32\ kbit/s stream occupies bit positions (1,\ 2,\ 3,\ 4) or (5,\ 6,\ 7,\ 8); .LP ii) a subrate stream occupies the same bit position(s) in each successive B\(hychannel octet; .LP iii) the order of transmission of the bits at each subrate stream is identical before and after multiplexing; and .LP iv) all unused bit positions be set to binary \*Q1\*U. .sp 1P .LP 2.1.2 \fIFlexible format multiplexing\fR .sp 9p .RT .PP This procedure will multiplex any combination of 8, 16 and 32\ kbit/s streams by allocating bits in each B\(hychannel octet to each subrate stream. This procedure always allows subrate streams to be multiplexed up to the 64\ kbit/s limit of the B\(hychannel. This procedure first attempts to accommodate the subrate streams by using the fixed format procedure of \(sc\ 2.1.1. Although there may be a sufficient number of available bits in the B\(hychannel octet, the attempt may fail because rule\ i) of \(sc\ 2.1.1 cannot be satisfied. If this attempt does fail, then flexible format procedure requires that: .RT .LP i) a subrate stream occupy the same bit position(s) in each successive B\(hychannel octet; .LP ii) the new subrate stream be added to the existing multiplex by inserting each successive bit of the new subrate stream into the earliest (lowest numbered) available bit position in the B\(hychannel octet; and .LP iii) all unused bit positions be set to binary \*Q1\*U. .bp .sp 1P .LP 2.2 \fIMultiplexing of rates other than 8, 16 and 32 kbit/s\fR .sp 9p .RT .PP Two technical approaches for multiplexing lower bit rate information streams (e.g.\ Recommendation X.1 rates) can be used: .RT .LP i) \fITime division multiplexing\fR .LP In this case, the two stage approach (rate adaption up to 8, 16 or 32\ kbit/s followed by multiplexing to 64\ kbit/s) as defined in \(sc\(sc\ 1.2 and 2.1 should be used. .LP \fINote\fR \ \(em\ Multiplexing schemes according to X\(hySeries Recommendations (e.g.\ X.50) may be used only in the context of 64\ kbit/s access through the ISDN to existing dedicated networks. .LP ii) \fIStatistical multiplexing\fR .LP a) for supporting packet mode terminals using either the D\(hychannel ro Recommendation\ X.25 protocols; .LP b) for circuit mode terminals or terminal adaptors on the B\(hychannel, see Recommendation\ V.120. \v'1P' .sp 2P .LP \fBRecommendation\ I.461\fR .RT .sp 2P .ce 1000 \fBSUPPORT\ OF\ X.21,\ X.21 | fIbis\fR \fB\ AND\ X.20 | fIbis\fR \fB\ BASED\ DATA | fR \fBTERMINAL\ EQUIPMENTS\ (DTEs)\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.461'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.461 %' .ce 0 .sp 1P .ce 1000 \fBBY\ AN\ INTEGRATED\ SERVICES\ DIGITAL\ NETWORK\ (ISDN)\fR .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984)\fR .sp 9p .RT .ce 0 .sp 1P .PP See Recommendation X.30, Volume VIII, Fascicle VIII.2. \v'1P' .sp 1P .RT .sp 2P .LP \fBRecommendation\ I.462\fR .RT .sp 2P .sp 1P .ce 1000 \fBSUPPORT\ OF\ PACKET\ MODE\ TERMINAL\ EQUIPMENT\ BY\ AN\ ISDN\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.462'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.462 %' .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP See Recommendation X.31, Volume VIII, Fascicle VIII.2. \v'1P' .sp 1P .RT .sp 2P .LP \fBRecommendation\ I.463\fR .RT .sp 2P .ce 1000 \fBSUPPORT\ OF\ DATA\ TERMINAL\ EQUIPMENTS\ (DTEs)\ WITH\ V\(hySERIES\ TYPE\fR | \fBINTERFACES\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.463'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.463 %' .ce 0 .sp 1P .ce 1000 \fBBY\ AN\ INTEGRATED\ SERVICES\ DIGITAL\ NETWORK\ (ISDN)\fR .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP See Recommendation V.110, Volume VIII, Fascicle VIII.1. .bp .sp 1P .RT .sp 2P .LP \fBRecommendation\ I.464\fR .RT .sp 2P .ce 1000 \fBMULTIPLEXING,\ RATE\ ADAPTION\ AND\ SUPPORT\ OF\ EXISTING\ INTERFACES\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.464'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.464 %' .ce 0 .sp 1P .ce 1000 \fBFOR\ RESTRICTED\ 64\ kbit/s\ TRANSFER\ CAPABILITY\fR .ce 0 .sp 1P .ce 1000 \fI(Malaga\(hyTorremolinos, 1984; amended at Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP Restricted 64 kbit/s transfer capability is defined as \*Q64 kbit/s octet\(hystructured capability with the restriction that an all\(hyzero octet is not permitted\*U. .sp 1P .RT .PP The procedures given in Recommendations I.460, I.461 (X.30), I.462 (X.31), I.463 (V.110) and I.465 (V.120) for rate adaption, multiplexing and support of existing interfaces for 64\ kbit/s, are fully compatible with the restricted 64\ kbit/s transfer capability except for the following limitations: .LP i) For time division multiplexing, the 8th bit of each octet of the 64\ kbit/s stream will be set to binary\ 1. This procedure is the same as that used for time division multiplexing into an unrestricted 64\ kbit/s channel where the full 64\ kbit/s is not utilized. .LP ii) Rate adapting an X.25 DTE, as contained in Recommendation\ I.462 (X.31) and rate adapting DTEs for circuit mode as described in Recommendation\ I.465 (V.120), for use with the restricted 64\ kbit/s transfer capability, is a matter for urgent further study. .PP The procedures in Recommendation I.462 (X.31) apply only to synchronous terminals. .PP The procedures in Recommendations I.460, I.461 (X.30), I.463 (V.110) and I.465 (V.120) apply to both synchronous and asynchronous terminals. \v'1P' .RT .sp 2P .LP \fBRecommendation\ I.465\fR .RT .sp 2P .ce 1000 \fBSUPPORT\ BY\ AN\ ISDN\ OF\ DATA\ TERMINAL\ EQUIPMENT\ WITH\ V\(hySERIES\ TYPE\fR | \fBINTERFACES\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.465'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.465 %' .ce 0 .sp 1P .ce 1000 \fBWITH\ PROVISION\ FOR\ STATISTICAL\ MULTIPLEXING\fR .ce 0 .sp 1P .ce 1000 \fI(Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .PP See Recommendation V.120, Volume VIII, Fascicle VIII.1. .sp 1P .RT .LP .rs .sp 15P .ad r Blanc .ad b .RT .LP .bp .sp 1P .ce 1000 \v'3P' SECTION\ 7 .ce 0 .sp 1P .ce 1000 \fBASPECTS\ OF\ ISDN\ AFFECTING\ TERMINAL\ REQUIREMENTS\fR .ce 0 .sp 1P .sp 2P .LP \fBRecommendation\ I.470\fR .RT .sp 2P .sp 1P .ce 1000 \fBRELATIONSHIP\ OF\ TERMINAL\ FUNCTIONS\ TO\ ISDN\fR .EF '% Fascicle\ III.8\ \(em\ Rec.\ I.470'' .OF '''Fascicle\ III.8\ \(em\ Rec.\ I.470 %' .ce 0 .sp 1P .ce 1000 \fI(Melbourne, 1988)\fR .sp 9p .RT .ce 0 .sp 1P .LP \fB1\fR \fBGeneral\fR .sp 1P .RT .PP 1.1 An ISDN is intended to support a wide range of new and existing terminals (TE1, TE2 +\ TA,\ NT2) of various capabilities and designed for different access interfaces. This is necessary to permit a full application of the\ ISDN service potential. .sp 9p .RT .PP 1.2 The purpose of this Recommendation is to provide direction to the potential functional requirements which may be called upon for any specific terminal. The terminal functions used are more specific examples of the general functions described in Recommendation\ I.310. In this issue of the Recommendation, it is primarily directed at the\ TE1 and\ TA devices operating at the basic rate. .sp 9p .RT .sp 2P .LP \fB2\fR \fBRelationship between terminals and services in the ISDN\fR .sp 1P .RT .PP 2.1 A terminal device can be described by the list of its functional and physical characteristics. This Recommendation is concerned with only those functional characteristics which the terminal requires in order to be compatible with the network to which the terminal is to be connected, i.e.\ the\ ISDN. .sp 9p .RT .PP 2.2 Figure\ 1/I.470 displays the functional relationship between user, terminal and network. The terminal functions may be those necessary to interface with the user or the network and also those necessary to provide the required network dependent services. .sp 9p .RT .LP .rs .sp 12P .ad r \fBFigure 1/I.470, (N), p.\fR .sp 1P .RT .ad b .RT .LP .bp .PP 2.3 The terminal being considered may be an individual element (e.g.\ a\ TE1) or a composite element (e.g. a\ TE2 +\ TA or\ TE1 +\ NT2). Figure\ 2/I.470 shows these arrangements. .sp 9p .RT .LP .rs .sp 15P .ad r \fBFigure 2/I.470, (N), p.\fR .sp 1P .RT .ad b .RT .PP A TE1 is generally considered as an ISDN interface compatible terminal, intended for use by an individual and connecting directly to the network at a\ T reference point or via an\ NT2 at a\ S reference point. .PP A TA provides the functions to adopt a non\(hyISDN compatible terminal to the network at either an\ S or\ T reference point. It normally provides the\ TE2 with compatibility to the network interface. The\ TE2 interconnects to the\ TA via a\ R reference point which may be real or virtual. .PP An NT2 is a multiple user device providing connection to a number of TE1s and/or\ TE2 +\ TAs (as for\ PBX). It provides\ S interfaces for these associated terminal devices and connects to the network via a\ T interface. .RT .PP 2.4 Certain common functions, in particular, concerning the signalling on the D\(hychannel will be found in all terminals connecting to the same type of interface. These functions are essential for interworking with the network and may be therefore considered mandatory. Individual terminals will also have a selected set of service related functions necessary for the services to which they are to be applied. .sp 9p .RT .PP 2.5 Each terminal will have an interface to the user. These interfaces are not a function of the\ ISDN and are not discussed in this Recommendation. .sp 9p .RT .PP 2.6 A terminal may in addition supply other services to the user, which are independent of the network. The functions are not part of this Recommendation. .sp 9p .RT .sp 2P .LP \fB3\fR \fBList of network related functions\fR .sp 1P .RT .PP 3.1 The following list of functions represent an initial view. Additional functions may be required, both in the terminal and the network as new services are identified. .sp 9p .RT .PP 3.2 The mandatory functions for basic rate terminals are given below in the following three Tables\ 1/I.470, 2/I.470 and\ 3/I.470 for the physical, link and network layers respectively. .bp .sp 9p .RT .ce \fBH.T. [T1.470]\fR .ce TABLE\ 1/I.470 .ce \fBMandatory physical layer functions\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(60p) | cw(90p) | cw(60p) . Functions Description Reference, Rec. I.430 _ .T& lw(60p) | lw(90p) | cw(60p) . Wiring configuration { Interconnection of one TE with one NT } \(sc 4 _ .T& lw(60p) | lw(90p) | cw(60p) . Line code Inverse of AMI \(sc 5.5 _ .T& lw(60p) | lw(90p) | cw(60p) . Frame structure { Alignment of bit, octet and frame } \(sc 6.3 _ .T& lw(60p) | lw(90p) | cw(60p) . { D\(hychannel contention control } { To control access to D\(hychannel } \(sc 6.1 _ .T& lw(60p) | lw(90p) | cw(60p) . Channel identification { To identify B\(hy, D\(hychannels } Rec. I.412 (Definition) _ .T& lw(60p) | lw(90p) | cw(60p) . Maintenance { Activities in support of maintaining network subscriber access and installations } \(sc 7 _ .T& lw(60p) | lw(90p) | cw(60p) . Electrical characteristics { Interfacing in passive bus interconnections } \(sc 8 _ .T& lw(60p) | lw(90p) | cw(60p) . Physical characteristics { Interface connector and contact assignments } \(sc 10 _ .TE .nr PS 9 .RT .ad r \fBTableau 1/I.470 [T1.470], p. 30\fR .ad b .RT .ce \fBH.T. [T2.470]\fR .ce TABLE\ 2/I.470 .ce \fBMandatory LAPD functions\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(60p) | cw(90p) | cw(60p) . Functions Description Reference, Rec. I.441 (Q921) _ .T& lw(60p) | lw(90p) | cw(60p) . Zero suppression Transparency transfer \(sc 2.6 _ .T& lw(60p) | lw(90p) | cw(60p) . Frame identification { To recognize and validate all frames } \(sc 2, 3 _ .T& lw(60p) | lw(90p) | cw(60p) . Establish transfer mode { Terminal transmits message to network for initiation } \(sc 5.3 _ .T& lw(60p) | lw(90p) | cw(60p) . Sequential control { Sequence integrity of frame transfer/reception on one connection } \(sc 3.5.2 _ .T& lw(60p) | lw(90p) | cw(60p) . Error detection { Detection of errors in transfer; format errors and operation errors } \(sc 5.8 _ .T& lw(60p) | lw(90p) | cw(60p) . Recovery { Recovery from detected errors and information outputs to management entity for unrecoverable errors } \(sc 5.8 _ .T& lw(60p) | lw(90p) | cw(60p) . Flow control { Flow control by modulo and acknowledgement } \(sc 3.6 _ .T& lw(60p) | lw(90p) | cw(60p) . Broadcast capability { Provision of broadcast data links that are identifiable by global TEI } \(sc 3.3.4.1 _ .TE .nr PS 9 .RT .ad r \fBTableau 2/I.470 [T2.470], p. 31\fR .ad b .RT .LP .bp .ce \fBH.T. [T3.470]\fR .ce TABLE\ 3/I.470 .ce \fBMandatory network layer functions\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(60p) | cw(90p) | cw(60p) . Functions Description Reference, Rec. I.451 (Q.931) _ .T& lw(60p) | lw(90p) | cw(60p) . { Identify message and process message } { To recognize and validate the message formats } \(sc 4 _ .T& lw(60p) | lw(90p) | cw(60p) . Call reference { To identify the call request at the local user\(hynetwork interface } \(sc 4.3 _ .T& lw(60p) | lw(90p) | cw(60p) . Support messages { A set of mandatory messages for basic call control procedures } \(sc 3 _ .T& lw(60p) | lw(90p) | cw(60p) . Support information elements { Specification of the message types } \(sc 4.4 _ .TE .nr PS 9 .RT .ad r \fBTableau 3/I.470 [T3.470], p. 32\fR .sp 1P .RT .ad b .RT .LP .sp 2 .PP 3.3 A list of service related functions is given below. Not all have yet been identified as related to a specific\ ISDN service. .sp 9p .RT .LP a) \fIOther terminal functions\fR .LP Terminal equipment may include some of the following service dependent functions: .LP \(em analogue\(hydigital conversion .LP \(em teleservice identification/selection .LP \(em supplementary service identification/selection .LP \(em stimulus to functional signalling conversion .LP \(em storage/memory .LP \(em code/rate translation .LP \(em encryption\(hydecryption .LP \(em speech pattern recognition .LP \(em speech synthesis .LP \(em authorization checking .LP \(em charge data recording .LP \(em network maintenance data recording .LP \(em network control capability service/maintenance .LP \(em echo control .LP \(em dialled number identification .LP \(em bearer service identification/selection. .LP b) \fIPower\fR .LP \(em local power supply .LP \(em power feeding .LP \(em terminal energizing control .LP \(em activation/deactivation. .LP .rs .sp 1P .ad r \fBBlanc\fR .ad b .RT .LP .bp