AudioCodes mediapack MP-500, User Manual

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SIP User's Manual 466 Document #: LTRT-12801
MP-500 MSBG
The SBC application above performs the following SIP message manipulations
(contributing to typical topology hiding):
SIP Manipulation From To
Inbound Source SIP URI User Name 7000 97000 (blue)
Source IP Group Name (SIP URI Host Name) 10.2.2.6 IP_PBX (blue)
Inbound Destination SIP URI User Name 1000 9721000 (red)
Destination IP Group Name (SIP URI Host
Name) 10.2.2.3 ITSP1 (red)
Relevant ini file parameters: IPOutboundManipulation ; IPInboundManipulation .
9.2.4 User Registration and Internal Database
To allow registrations to traverse the SBC, the device must be configured with at least one
IP Group of type USER. USER IP Groups represent a group of user agents that share the
following characteristics:
„
Perform registrations and share the same serving proxy\registrar
„ Possess identical SIP and media behavior
„ Reside on the same Layer-3 network and are associated with the same SRD
Typically, the device is configured as the user agent's outbound proxy and the device is
configured (using the IP2IP Routing table) to route requests received from this IP Group to
the serving proxy and vice versa. Survivability can be achieved using the alternative
routing feature.
9.2.4.1 Initial Registration Request Processing
Registration requests have different processing policies than other SIP methods:
1. Determining source and destination URL's:
•
The source URL is obtained from the To header
•
The destination URL is obtained from the Request URI
2. Classification: The REGISTER classification process is the same as the general
classification process (described in previous sections). The source IP Group must be
of type USER. If classification fails or the source IP Group is not of type USER, the
registration is rejected.
3. Routing: The REGISTER routing is performed using the IP2IP Routing table:
•
The destination type can only be an IP Group (i.e., no specific address\Request
URI).
•
If the IP Group is of type SERVER, the REGISTER is routed to the IP Group's
Proxy Set.
•
If the IP Group is of type USER, then the device replies with a 200 OK response
(used for Survivability) and the REGISTER is not forwarded.
4. The expiry time (SIP Expires header) in the outgoing REGISTER is obtained from the
parameter SBCRegistrationTime.