Handling failed connection requests

This topic shows are events are generated and how cleanup occurs when TUPConnectReq connection requests fail in the following situations:

Subscriber busy

If the called number is busy, TUPConnectReq can fail. The following illustration shows how events are generated and how cleanup occurs (before a reconnection is attempted) when a connection fails because the subscriber is busy:

 

Circuit blocked

If the far exchange blocked the circuit, TUPConnectReq can fail. The following illustration shows how events are generated and how cleanup occurs (before a reconnection is attempted) when a connection fails because the circuit is blocked:

 

Circuit reset

If the far end exchange resets the circuit, TUPConnectReq can fail. The following illustration shows how events are generated and how cleanup occurs (before a reconnection is attempted) when a connection fails because the circuit has been reset:

 

Unknown or missing response

If an intelligible answer to the initial address message (IAM) is not received, TUPConnectReq can fail. The following illustration shows how events are generated and how cleanup occurs (before a reconnection is attempted) when a connection fails because there is an unknown or missing response: