AT&T BCM50 IP Phone User Manual

AT&T IP Flexible Reach Service
Nortel BCM50 Release 3.0 SIP Configuration Guide
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Backup to a secondary AT&T IP Border Elements is supported on the BCM50
using the SIP “OPTIONS” keep-alive approach. The BCM50 will send SIP
“OPTIONS” messages to the AT&T IPBEs listed in the Outbound Proxy Table and
send VoIP calls based on whether or not the BCM50 receives a “200 OK” from
the IPBEs and the Load-balancing Weights values set for each entry.
Figure 15: Outbound Proxy Table for failover to secondary AT&T IPBEs
A Load-balancing weight of 0 means the IPBE is used as last resort. Any non-
zero number value indicates the ratio of calls (the specific IPBE’s load-balancing
weight to sum of all IPBE’s load-balancing weights) the BCM50 will send out to
each IPBE. In this example, the BCM50 will send 1 call for every 1 call made (in
essence, all calls) to the IPBE with IP address and use IPBE as backup.
Additionally, the AT&T IP Flexible Reach service will send incoming calls to the
BCM50 from multiple IP border elements. The BCM50 will accept calls from any
border element without additional configuration.
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