Nortel DMS-250 Reference Manual page 9

Notification Indicator 4-6
Original Called Number 4-6
Progress Indicator 4-6
Redirecting Number 4-6
Redirection Number 4-6
Restart Indicator 4-7
Transit Network Selection 4-7
User-to-User 4-7
Locking shift to codesets 4-7
Message functions 4-7
Q.931 message descriptions 4-8
Q.931 message information elements 4-14
Q.932 message descriptions 4-21
Q.932 message information elements 4-22
Congestion and Network Flow Control 4-23
User Congestion 4-23
Network Flow Control 4-23
User Congestion and Network Flow Control Interaction 4-23
Call control procedures
Introduction 5-1
DMS-250 switch functions and services 5-1
Switch network parameter 5-1
Call establishment at the originating exchange 5-3
User call request 5-3
Call types supported 5-4
Network control system 5-4
Call authorization 5-4
Call translation 5-5
Translation example 5-5
B-channel allocation and negotiation 5-8
Call proceeding and termination 5-9
Call establishment at the terminating exchange 5-10
Network call request with SETUP message 5-10
Selection of PRI B-channel for termination 5-10
Terminations and user responses 5-11
Terminating to a PRI 5-11
Termination to a PBX 5-13
Termination to a non-ISDN trunk 5-13
Termination to Enhanced Voice Services ARU 5-16
Reseller switch setup and release 5-22
Suppcode collection 5-22
Call takedown for normal call clearing 5-24
User-initiated normal call clearing 5-24
Network-initiated normal call clearing 5-25
Disconnection of an EVS call 5-26
Cause and treatment handling 5-29
Standard cause and treatment handling 5-30
Enhanced cause and treatment handling 5-31
Q.931 cause values 5-32
Location codes 5-32
Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
Contents vii
5-1