SDP Version Change without SDP Body Change

When an SRTP call is made through the Oracle Communications Session Border Controller and a UE sends a reINVITE, there may be no change in the SDP contents. When the other UE responds, some devices will increment the o= line’s session version, despite no SDP change. Normally the change in SDP version indicates that the SDP has changed, which would otherwise require the Oracle Communications Session Border Controller to modify the media flow set-up. In order to leave the media flows unchanged when session version changes but the rest of the SDP does not, an option is configured in the media-manager-config.

If the Oracle Communications Session Border Controller attempts to modify these media flows when unnecessary, calls could be dropped by the system disrupting media packet sequence number synchronization.

The ignore-reinv-session-ver option is set to handle this situation. When configured, the Oracle Communications Session Border Controller compares the current SDP received from a UE against the previously-received SDP from the same UE. If the SDP in the newer and older messages is the same, the Oracle Communications Session Border Controller ignores any changes to the session-version and will not modify the media flow portion of the call.

Note:

When the SDP change is only a reordering of SDP lines without any other change, the option has no effect.

SDP Version Change Configuration

To configure media over TCP:

In Superuser mode, type configure terminal and press Enter.
```
ORACLE# configure terminal
```
Type media-manager and press Enter to access the media-level configuration elements.
```
ORACLE(configure)# media-manager
ORACLE(media-manager)#
```
Type media-manager and press Enter to begin configuring media over TCP.
```
ORACLE(media-manager)# media-manager
ORACLE(media-manager-config)#
```
options — Set the options parameter by typing options, a Space, the option name ignore-reinv-session-ver with a “plus” sign in front of it, and then press Enter.
```
ORACLE(media-manager-config)# options +ignore-reinv-session-ver
```
If you type the option without the “plus” sign, you will overwrite any previously configured options. In order to append the new options to the realm configuration’s options list, you must prepend the new option with a “plus” sign as shown in the previous example.

Save and activate your configuration.