ISDN Call Processing Overview
November 2009 326
If the call is made using Switched 56 robbed bit signaling (not
ISDN), there is an additional waiting period between sending the
L4L3mCLEAR_REQUEST and receiving the L3L4mCLEAR_
REQUEST indicating the channel is available. This interval is equal
to the value of the guard_interval_timer and is usually 100 ms. Refer
to Chapter , Robbed Bit Signaling on page 264 for more information
on robbed bit signaling timers.
Figure 51. ISDN Call Clearing - Initiated by Network
Network Module Host
RELEASE
DISCONNECT
RELEASE COMPLETE
L3L4mDISCONNECT
L4L3mCLEAR_REQUEST
L3L4mCLEAR_REQUEST