Local Handling Of Sip 3Xx - AudioCodes Mediant 4000 SBC User Manual

User's Manual
5. The prefix is removed before the resultant INVITE is sent to the destination.
The process of this feature is described using an example:
1. The device receives the Redirect server's SIP 3xx response (e.g., Contact:
<sip:User@IPPBX:5060;transport=tcp;param=a>;q=0.5).
2. The device replaces the Contact header value with the special prefix and database
key value as user part, and with the device's URL as host part (e.g., Contact:
<sip:Prefix_Key_User@SBC:5070;transport=udp>;q=0.5).
3. The device sends this manipulated SIP 3xx response to the Far-End User (FEU).
4. The FEU sends a new request with the Request-URI set to the value of the received
3xx
sip:Prefix_Key_User@SBC:5070;transport=udp).
5. Upon receipt of the new request from the FEU, the device replaces the Request-URI
with
sip:Prefix_User@IPPBX:5070;transport=tcp;param=a).
6. The device removes the user prefix from the Request-URI, and then sends this
Request-URI
sip:User@IPPBX:5070;transport=tcp;param=a).

20.9.1.2 Local Handling of SIP 3xx

The device can handle SIP 3xx responses on behalf of the dialog-initiating UA and retry the
request (e.g., INVITE) using one or more alternative URIs included in the 3xx response.
The new request includes SIP headers from the initial request such as Diversion, History-
Info, P-Asserted-Id, and Priority. The source and destination URIs can be manipulated
using the regular manipulation mechanism.
The device sends the new request to the alternative destination according to the IP-to-IP
Routing table rules. (where the 'Call Trigger' field is set to 3xx). It is also possible to specify
the IP Group that sent the 3xx request as matching criteria for the re-routing rule in this
table ('ReRoute IP Group ID' field).
Version 7.2
Figure 20-7: SIP 3xx Response Handling
response's Contact
the new destination
to the
header
address
new destination
439
20. SBC Overview
(e.g., RequestURI:
(e.g., RequestURI:
(e.g., RequestURI:
Mediant 4000 SBC