Network management is the process of planning, organizing, monitoring, and controlling a communication-oriented data processing or information system. The architecture provided to assist in network management of SNA systems is called management services and is implemented as a set of functions and services designed to capture and use the information needed for effective management.

VTAM® can exchange management services information with other systems that provide management services transport, or multiple-domain support, such as AS/400®, Communication Manager/2, or other VTAM systems. This type of information flows between architected transaction programs in the respective systems over SNA sessions. The network management sessions that carry this exchange use either the CPSVCMG or SNASVCMG mode names. For further information about management services concepts and architecture, see Systems Network Architecture Management Services Reference.

The limited resource function is also available on some control point sessions used for network management flows, though for these sessions, it differs from the way it operates for noncontrol point sessions. For network management flows using the CP SNASVCMG session, a session is deactivated only when there are not any management services (MS) transport transactions outstanding, in addition to the session being inactive.

By coding the LIMINTCP start option, you specify the interval to retain a free CP SNASVCMG session for a resource that is defined as limited (with the LIMRES operand). The CP SNASVCMG session is used for some network management flows.

To define limited resource management for network management flows, perform the following steps:

1. Determine which network connections you want to define as limited. These are the lines whose costs are determined by the length of connect time.
2. Define the network connections to VTAM by coding LIMRES=YES on the GROUP, LINE, or PU definition statement. LIMRES is valid only for PU type 2.1.

   You can specify a line, a group of lines, or a PU as a limited resource for the following major nodes:

   • External communication adapter
   • Local SNA (PU only)
   • MODEL (PU only)
   • NCP
   • Switched (PU only)
3. Determine the interval for VTAM to search the queue.

   As a starting point, the interval should be at least 1 second less than half the shortest line time cost interval. For example, if the shortest time cost interval is 1 minute, the interval should be 29 seconds.

   Specify the interval to VTAM with the LIMINTCP start option. If you do not code LIMINTCP, the limited resource function will not be supported for network management flows. See z/OS Communications Server: SNA Resource Definition Reference for information about how to specify the LIMINTCP start option.