Configuring Sip Response Codes For Alternative Routing Reasons - AudioCodes Mediant 4000 SBC User Manual

Name
Match
Source Tag
Action
Destination Type
Destination IP Group
•
Routes calls from the ITSP (identified by the source tag name-value
"Type=ITSP") to the IP PBXs (identified by the specific port assigned to the IP
PBX by the value of the destination tag name "Port"):
General
Index
Name
Match
Source Tag
Action
Destination Type
Routing Tag Name
25.3 Configuring SIP Response Codes for Alternative
Routing Reasons
The Alternative Routing Reasons table lets you configure up to 20 SIP response codes for
call release (termination) reasons. If a call (outgoing SIP dialog-initiating methods, e.g.,
INVITE, OPTIONS, and SUBSCRIBE messages) is released as a result of a configured
SIP code (e.g., SIP 406), the device does alternative routing as follows: If the destination
Proxy Set is configured with multiple IP addresses (see Configuring Proxy Sets on page
363), the device first attempts to route the call to one of these IP addresses, starting with
the first listed address. If unsuccessful, the device then searches for an alternative routing
rule in the IP-to-IP Routing table (see 'Configuring SBC IP-to-IP Routing Rules' on page
499).
Typically, the device performs alternative routing when there is no response at all to an
INVITE message. This is done after a user-defined number of INVITE re-transmissions,
configured by the SIPMaxRtx parameter. In such a scenario, the device issues itself the
SIP response code 408 (Request Timeout). Alternative routing is only done if you have
configured the response code in the Alternative Routing Reasons table.
You can also configure alternative routing for the following proprietary response codes, if
configured in the table, that are issued by the device itself:

805 IP Profile Call Limit: The device generates the response code when Call
Admission Control (CAC) limits (e.g., maximum concurrent calls) are exceeded for an
IP Group (or SRD). The CAC rules are configured in the Admission Control table (see
''Configuring Admission Control'' on page 487). When this occurs, the device sends a
SIP 480 (Temporarily Unavailable) response to the SIP entity. In such a scenario, an
alternative route configured in the IP-to-IP Routing table can be used.
User's Manual
PBX-to-ITSP
Type=PBX
IP Group
ITSP
2
ITSP-to-PBX
Type=ITSP
Destination Tag
Port
516
Mediant 4000 SBC
Document #: LTRT-40203