INFO: SNA Server Does Not Support Full Duplex APPC

SUMMARY

APPC is a peer-oriented program-to-program API where either Transaction Program (TP) can initiate a conversation. However, APPC/LU6.2 traditionally is half-duplex, where after the conversation is established, only one TP has direction to send on a conversation at a time. The state of the conversation, as viewed by a particular TP, governs which APPC verbs can be issued by the TP at a particular time. If the local TP views the conversation as being in a "send" state, then the partner TP would also be in a send state.

IBM now supports "full duplex" APPC where either program can issue both send and receive verbs at the same time, though this is a fairly new implementation of APPC.

The following is the option to set for full duplex functionality: SNA Server does not support option set 112; it only supports half-duplex, although either end can initiate the conversation.