### Subscription Update

Use the Subscribe push type to make an asynchronous request to a phone to re-subscribe and update all the values defined in the syntax examples above.

NOTE: See Chapter 3: Creating Push Messages for more details on sending a Subscribe Push Request to the telephone.

An exact string-based comparison is done to match the subscription URIs against the values in the SUBSCRIBELIST. If the subscription server URI does not exactly match the values in the SUBSCRIBELIST, the subscription request is aborted.