Question 18/II - Grade of service during and after a total failure of
network components or traffic peak conditions
(new Question)

Considering

(a) that due to accumulated demands during a period of a failure (see
Recommendation 550, section 3.1, points a) and b)), the network
components will experience a heavy traffic load during and after a
failure condition;

(b) that depending on daily traffic profile such heavy traffic load may
also occur after having removed severe overload condition;

(c) that Recommendation E.550 concerning the Grade of Service and
new performance criteria only under failure conditions does not cover
the period of time immediately after a failure condition or heavy
traffic
peak have been removed;

(d) that in case of lack of facilities for re-routing in the network the
whole traffic offered has to be processed,

1. What parameters should be proposed for evaluation of Grade of
Service of network components during and after a failure condition or
severe overload traffic condition?

2. What is the way of calculating and measuring these parameters?

3. What standards should be proposed for these parameters?

Note - Liaison needs to be established with Study Group XI (Working
Party XI/4, Digital Switching) with the objective to define techniques
for
recognizing the condition and regulating the operation of an exchange
during excessive traffic peaks.