Nortel DMS 100 Series Maintenance Manual page 107

Figure 4-9 Call release sequence DC5A to DC5A (originator release)
t
i
m
e
*
Start T1' and T5
*
Stop T1' and T5
Call release sequencing from a DC5A line to a DC5A line (originator release).
1. AMC to originating exchange When a calling subscriber goes on-hook,
2. Originating exchange to terminating exchange During the release
3. Terminating exchange to AMC When the terminating exchange receives
4. Terminating exchange to originating exchange The terminating exchange
5. AMC to terminating exchange When the terminator goes on-hook, the
DMS-100 Family Remote Switching Center Multi-Access Maintenance Manual XPM11 and up
DC5A/DC5ADD
clear forward
idle
the AMC node sends a clear forward signal to the originating exchange.
The originating exchange sends back an idle signal to the AMC node.
sequence the originating exchange sends a REL message to the
terminating exchange and starts the T1' and T5 timers.
the REL message the exchange starts the release sequence. To start the
release sequence the terminating exchange sends a clear forward message
to the AMC node.
sends a RLC message to the originating exchange. The RLC message
releases the outgoing trunk in the previous exchange, and stops the T1' and
T5 timers.
AMC node sends an idle signal to the terminating exchange. The idle
signal releases the outgoing trunk and establishes an idle condition.
RSC-M Signaling and Communications 4-17
originating
office
BTUP
speech
REL
*
RLC
*
idle
terminating
office
DC5A/DC5ADD
clear forward
idle