Nortel DMS-250 - PRI-to-PTS

6-8 PRI interworking
297-2521-106 Standard 23.01 March 2001
PRI-to-PTS
The call scenario in Figure 6-6 illustrates interworking between ISDN and
PTS where the call is routed over a PTS trunk after leaving ISDN.
The progress message, with PI set to “not end-to-end ISDN,” is sent back
upon encountering the PTS trunk. The progress message is mapped into the
Address Complete Message (ACM) with “interworking encountered” bits
set at the called-access switch. The ACM is then mapped to a progress at the
calling-access switch.
Figure 6-6
Interworking between PRI and PTS trunk
—PRI-to-PTS
PBX PBX
DMS-250
SETUP IAM
SETUP
(PRI)
(ISUP)
(PRI)
CALL PROC
ACM
CONN CONNANM
CONN ACK
CONN ACK
Active call
REL
RLC
On–hook
REL COM
PBX
(PTS)
Seizure
Digits
Ringing
Answer
REL
REL
REL COM
CALL PROC
PROG PROG
DISC
On–hook
DMS-250