CA Support Is Optional

Support for APM is optional for both HCAs and TCAs:

• Software may determine whether or not an HCA supports APM by executing the Query HCA verb.

• During the connection establishment communications message exchange, the CM sending the REQ message may supply alternate path information to the remote CA's CM. If the remote CA supports APM, the REP message's 2-bit Failover Accepted field will contain 00b, indicating that the alternate path information was accepted and the remote CA therefore supports APM.

A CA that doesn't support APM may ignore the alternate address information if softwarep supplies it in the QP's or EEC's setup.