AT&T NORTEL BCM50 User Manual

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AT&T IP Flexible Reach Service 
Nortel BCM50 Release 3.0 SIP Configuration Guide 
 
 
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logo and all other AT&T marks contained herein are trademarks of AT&T 
Intellectual Property and/or AT&T affiliated companies.  All other 
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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 135.25.29.135 and use 
135.25.29.79 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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