Introduction

The SIP UPDATE method allows a client to update parameters of a session (such as the set of media streams and their codecs) but has no impact on the state of a dialog. In that sense, it is like a re-INVITE, but unlike re-INVITE, it can be sent before
the initial INVITE has been completed. This makes it very useful for updating session parameters within early dialogs.

SIP UPDATE messages are send for different reasons.

• CLIP update
• Check if device is still present (keep alive)
• Update other session parameters

Keep alive

Some platforms send a SIP UPDATE message to check if the client is still present, if the device does not answer or send the wrong response, the call is disconnected by the platform.

Error reported by the customer: Call is disconnected after ... minutes.

How to change the SIP UPDATE support

There are 2 Methods to enable/disable SIP update.

1. Provisioning
2. Web-interface (Software 241 or higher.)

Provisioning

Web-interface

From software 241 or higher, the SIP UPDATE can be enabled/disabled via the web-interface.

• Open the web-interface
• Go to: Settings - Telephony - Advanced VoIP Settings - SIP UPDATE

Allow-header

Option disabled: Allow: INVITE, ACK, CANCEL, BYE, OPTIONS, INFO, SUBSCRIBE, NOTIFY, REFER

Option enabled: Allow: INVITE, ACK, CANCEL, BYE, OPTIONS, INFO, SUBSCRIBE, NOTIFY, REFER, UPDATE