I think Weizhong means implmentation of GSIAPI like one from Globus which does have
own communication protocol incompatible with TLS.

I don't believe there are any protocol changes between the secure-communication in GSI-API (GSI-OpenSSL) and TLS.

As Weizhong mentions, there are additional validation steps in the event that GSI detects the presence of a proxy-extension within a certficate during handshake. But nothing that affects wire protocol.

-Duane