CONNECT, or RELEASE_COMPLETE message from Q.93B (all other messages are ignored by Q.93B). After you receive the CONNECT message, you can use the virtual channel.
Respond to a SETUP message from Q.93B with a CALL_PROCEEDING, ALERTING, CONNECT, or RELEASE_COMPLETE message to Q.93B. After you receive the CONNECT_ACK message, you can use the virtual channel.
Release Procedure
To clear an active call or a call in progress, send a RELEASE message down to Q.93B and wait for a RELEASE_COMPLETE from Q.93B. Any time you receive a RELEASE_COMPLETE message from Q.93B, release the virtual channel if the call is active or in progress.
Q.93B never sends a RELEASE message to the end user; it will always send a RELEASE_COMPLETE. Only send the RELEASE_COMPLETE message when rejecting a call in response to a SETUP message from Q.93B. At any other time, to reject or tear down a call, send a RELEASE message to Q.93B.
Exception Conditions
If for any reason Q.93B cannot process a SETUP message received from an end user, the SETUP_ACK is returned with an error value set, and call setup is not continued. The error value will be one of the cause codes specified in the ATM Forum UNI standard.
94 SunATM 3U CompactPCI Adapter Installation and User’s Guide • February 2001
