5.3Recommendation I.352

    NETWORK PERFORMANCE OBJECTIVES FOR CONNECTION PROCESSING
                       DELAYS IN AN ISDN


1.     General

1.1    Reference model

       This Recommendation provides network performance  objectives  for
connection  processing  delays.  The   reference   model   provided   in
Recommendation I.34X was used to provide a baseline reference configuration. In 
addition Recommendation Q.709 was taken into account in the determination of 
values.

Note - This Recommendation does not take into account the performance  of  private
networks. In case of private networks connected to the ISDN the recommended values 
refer to the T reference point. The S reference point applies in cases where S and 
T are coincident.

1.2    Measurement

       All parameter values are specified at network boundaries. These values  are
measured at the ISDN S/T reference points using call processing  message  transfer
events (MTEs) (Recommendation Q.931 messages or the corresponding Signalling System 
No. 7 messages), where appropriate.

1.3    Network conditions

       The values for delay given in this Recommendation include an allowance  for
the effects on delay  that  might  be  introduced  during  a  nominal  busy  hour.
Consideration was given to the possibility that individual busy hours might not be 
coincident. The values also include the effects of network component failures. The specified 
values do not apply under conditions of network unavailability. These  delays  are
expressed in terms of mean and 95% probability values.

1.4    User delay

       Values are provided for measurements made at a  single  connection  element
boundary as well as measurements made between two connection element boundaries. This 
allows for calculations that would avoid inclusion of  any  delay  that  might  be
introduced by users or user equipment.

1.5    Allocation

       Overall connection processing delays between S/T reference  points  can  be
divided into sub-values for each connection element  including  the  national  and
international portions.

1.6    Basic connection

       Connection processing delays are only defined for a  basic  connection  and
therefore do not provide for any effects that might be introduced by supplementary 
services. (See Figure 1/I.352).

1.7    Phases

       Connection processing delay values are specified for the connection  set-up











and disconnection phase.

















































                                  FIGURE 1/I.352
                                         
              Procedure for a simple circuit switched call (example)