You assign outbound or local signaling paths to a transport class using the CLASS keyword of the PATHOUT or LOCALMSG statements or, after IPL, using the SETXCF (START or MODIFY) PATH command. (Inbound signaling paths are not segregated by transport class.) Figure 1 shows the syntax.

[PATHIN                                                  ]
[          {DEVICE(device-number[,device-number]...) }   ]
[          {STRNAME(strname[,strname]...)            }   ]
[          [MAXMSG(max-messages)]                        ]
[          [RETRY(retry-limit)  ]                        ]
[PATHOUT                                                 ]
[          {DEVICE(device-number[,device-number]...) }   ]
[          {STRNAME(strname[,strname]...)            }   ]
[          [MAXMSG(max-messages)]                        ]
[          [RETRY(retry-limit)  ]                        ]
[          [CLASS(class-name)]                           ]
[LOCALMSG                                                ]
[           MAXMSG(max-messages)                         ]
[          [CLASS(class-name)]                           ]

If you implement signaling through a list structure, you use the STRNAME keyword of the PATHIN or PATHOUT statement to specify the name(s) of the list structure(s) you want to use for PATHIN or PATHOUT on that system. If you assign a structure to a transport class, every outbound signaling path that MVS™ starts through that structure to other systems is also assigned to that transport class. (If the list structure is not explicitly assigned to a transport class, it is implicitly assigned to the default transport class.)

If you implement signaling through CTCs, you can assign each CTC to a transport class. Because a CTC connects to a specific system, you have more flexibility to add paths between systems within a class.

Assign signaling paths to a transport class based on the amount of message traffic you expect the class to handle. One signaling path may be sufficient for most transport classes; however, assign two (or more) paths if you want a redundant path available to the transport class or require additional capacity.

An XCF group usually uses only the signaling paths associated with the transport classes to which the group is assigned. However, if there are no paths available to a group in any of its assigned transport classes, messages in the group are routed to other paths.

Failure to assign a signaling path to a transport class can degrade the performance of the signaling service for XCF groups assigned to that class. In this case, the groups compete for the signaling resources of transport classes assigned to other XCF groups.