AT&T IP Flexible Reach and AT&T IP Flexible Reach with AT&T Business in a BoxNortel BCM50 Release 3.0 SIP Configuration Guide*Nortel, Nortel Networks, Nortel (Logo), the Globemark, CS1000 are trademarks of Nortel Networks.Issue 1.5 Page 21 of 384.3 SIP Proxy ParametersUnderConfiguration Resources Telephony Resources: Select moduletype “IP Trunks” and click on the “Sip Proxy” tab (see figures below).Figure 13: Selecting IP Trunk ModuleFigure 14: Sip Proxy ParametersFor IP Flexible Reach: Populate the “Domain” as the IP address of the AT&T IPBorder Element.For AT&T IP Flexible Reach with AT&T Business in a Box: The “Domain” will bethe IP address of the local interface of the AT&T Business in a Box router.Contact your local AT&T Customer Care representative for the IP addresses andmore information.