UPDATE Method

Overview

The UPDATE method allows a UAC to update parameters of a session, such as the SDP and session timers. The UPDATE has no impact on the state of a dialog.  In that sense, it is like a re-INVITE, except that it can be sent before the initial INVITE has been completed. This makes it very useful for updating session parameters within early dialogs. The UPDATE method allows a greater control over a SIP session including, but not limited to, the following parameters:

 

IMG Support

The IMG supports the following for SIP UPDATE:

 

RFC

3311 The Session Initiation Protocol (SIP) UPDATE Method

 

Configuration

The SIP UPDATE method is accepted without user intervention and cannot be configured or disabled.

 

Call Flows

The following calls flows are a few possible transactions. For more call flows refer to RFC 3311 and RFC 3261.

IMG handles a UAS UPDATE transaction while in a UAS INVITE transaction

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IMG initiates a UAC UPDATE transaction while in a UAS INVITE transaction

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IMG handles a UAS UPDATE transaction while in a UAC INVITE transaction

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IMG initiates a UAC UPDATE transaction while in a UAC INVITE transaction

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IMG handles a UAS UPDATE transaction while in answered state

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IMG initiates a UAC UPDATE transaction while in answered state

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