Dialogic 6.2 - Manual (Page 326)

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