The procedure is initiated by the user, who shall send a SUSPEND message containing the current call reference; start timerT319 and enter the Suspend Request state. The user may optionally include in this message a bit sequence (e.g. IA5 characters) to be known by the application or human user, and by the network, as the call identity for subsequent reconnection. Where no call identity information is included by the user, (e.g. the Call identity information element is absent or empty) the network shall store this fact so that resumption is possible only by a procedure conveying no call identity information.
Note - If the Call identity information element is present with a null length, the message shall be handled as if it was absent.
The default maximum length of the call identity value within the Call identity information element is eight octets. If the network receives a call identity value longer than the maximum length supported, the network shall truncate the call identity value to the maximum length; take the action specified in 5.8.7 and continue processing.