In order to let the phone generate short compact SIP headers this option should be enabled. Otherwise the old usual style of SIP headers will be generated.
Advanced - SIP/RTP (Tab) - SIP(Section)__Use SIP Compact Headers
N/A
| Parameter | Valid value |
|---|---|
| <short_form perm="PERMISSIONFLAGS">VALIDVALUE</short_form> | <on>, <off> |