SIP REGISTER Forwarding After Call-ID Change

This feature addresses the case when an endpoint reboots and performs a third party registration before its old registration expires. During this reregistration, the contact header is the same as it was pre-reregistration. As a consequence of the reboot, the SIP Call-ID changes. In this situation, the Oracle® Enterprise Session Border Controller does not forward the REGISTER to the registrar, because it believes the endpoint is already registered, based on a previous registration from the same Contact: header URI.

To remedy this problem, the Oracle® Enterprise Session Border Controller now keeps track of the Call-ID in its registration cache. The forward-reg-callid-change option in the global SIP configuration element forces the Oracle® Enterprise Session Border Controller to forward a REGISTER message to the registrar when the Call-ID header changes in a REGISTER message received from a reregistering UAC.

SIP REGISTER Forwarding Configuration

To configure SIP REGISTER forwarding after a Call-ID change:

In Superuser mode, type configure terminal and press Enter.
```
ORACLE# configure terminal
```

Type session-router and press Enter.

ORACLE(configure)# session-router
ORACLE(session-router)#

Type sip-config and press Enter. The system prompt changes to let you know that you can begin configuring individual parameters.
```
ORACLE(session-router)# sip-config
ORACLE(sip-config)#
```
options—Add this feature to a new or an existing SIP configuration:
If you do not currently have a SIP configuration, you can add the option by typing options, a Space, and then forward-reg-callid-change.
```
ORACLE(sip-config)# options forward-reg-callid-change
```
For an existing SIP configuration, select the SIP configuration so that you can add this feature to it. Then, to add this option to a list of options that you have already configured, type options, a Space, the plus sign (+), and the forward-reg-callid-change option.
```
ORACLE(sip-config)# options +forward-reg-callid-change
```
If you type options forward-reg-callid-change without the plus (+) sign, you will remove any previously configured options. In order to append the new option to the options list, you must prepend the new option with a plus sign as shown in the example above.
Save and activate your changes.