SIP maddr Resolution
Release S-C6.2.0 provides enhanced resolution of addresses found in SIP contact headers, or in the maddr (multicast address) parameter of SIP 3xx REDIRECT messages. Previous releases resolved these addresses as either a host address or as a session agent name. With Release 6.2.0 these addresses can also be resolved as session agent group (SAG) names.
Support for SAG-based resolution is provide by a new sip-config parameter, sag-lookup-on-redirect. By default, SAG lookup is disabled, providing compatibility with prior releases.
The following sample SIP REDIRECT and ACLI configuration fragment illustrate enhanced processing.
Status-Line: SIP/2.0 302 Moved
Message Header
Via: SIP/2.0/UDP
192.168.200.224:5060;branch=z9hG4bKa0fs40009o90sc8oo780.1
From: <sip:1111@192.168.1.222:6000>;tag=1
To: sut <sip:2223@192.168.1.224:5060>;tag=11
Call-ID: 1-28515@192.168.1.222
CSeq: 1 INVITE
Contact: <sip:1111@192.168.1.223;maddr=test.acmepacket.com>
Privacy: user;id;critical;session
P-Preferred-Identity: sipp <sip:sipp@192.168.200.222:5060>
P-Asserted-Identity: abc.com
Subject: abc
Proxy-Require: privacy,prack,abc
Content-Length: 0
session-group
group-name test.acmepacket.com
description
state enabled
app-protocol SIP
strategy Hunt
dest
192.168.200.222
192.168.200.223
...
...
In this case, when the Oracle® Enterprise Session Border Controller receives the 302, it resolves the information from maddr to a SAG name. In the above example, it will resolve to the configured SAG – test.acmepacket.com. The destinations configured in SAG test.acmepacket.com will be used to route the call.
SAG-based address resolution is based on the following set of processing rules.