Nortel Networks NN43001-563 - Manual (Page 75)

Fallback to alternate facilities 75
problems, Stepback on Congestion allows a new route to be found for the
call (for instance, the PSTN). The route selected depends on the customer’s
database. If an alternate route is not configured in the route list, the calls
rejected by IP Trunk 3.01 (and later) is routed to some other treatment.
Fallback is optional, based on the configuration of the route list.
Figure 22 "Example of a fallback to alternate facilities situation" (page 75)
shows the fallback to alternate facilities functionality.
Figure 22
Example of a fallback to alternate facilities situation
Fallback in IP Trunk 3.01 (and later)
In QoS monitoring, the local node queries the remote node and gets a
response; the remote node queries the local node and gets a response.
If the remote node cannot query the local node, QoS monitoring is not
available. When an IP Trunk 3.01 (and later) node uses a Gatekeeper to
resolve an address, IP Trunk 3.01 (and later) cannot monitor QoS and
provide fallback. This function resides with the device resolving the address.
As a result, for all calls going to the Gatekeeper, such as in IP Peer
Networking, no fallback can occur. The call either goes through with
possibly a lower QoS, or the call clears instead of falling back. All QoS
control is in the hands of the Gatekeeper.
Nortel Communication Server 1000
IP Trunk Fundamentals
NN43001-563 01.01 Standard
Release 5.0 30 May 2007
Copyright © 2007, Nortel Networks
.