Inbound message buffers are segregated by signaling path. Buffers associated with an inbound signaling path do not receive messages over any other inbound signaling path.

The message buffer space available to inbound messages is specified or defaulted on the MAXMSG parameter of the PATHIN statement. If you implement signaling with CTCs, you can specify the message buffer space for each inbound signaling path. If you implement signaling through list structures, the message buffer space you define for the structure on a system takes effect for all the paths started by that system through that list structure.

When specifying message buffer space for an inbound signaling path, consider the size and frequency of the messages to be received on that path. You want to provide enough message buffer space to allow the inbound signaling path to receive messages without causing messages to back up on the sending system. To determine the message size, note the class length of the sending system's transport class.

If the message buffer space for an inbound signaling path is too small to support a message sent from a remote system, MVS™ exceeds the buffer space limit to receive the message.