NET/MASTER Management Services (MS) Operator's Guide

INMC Link Failures
Communicating With Remote Systems
8–10 106379 Tandem Computers Incorporated
INMC Link Failures An INMC link is made up of objects called session types and units:
Session types are the communication access methods used by the INMC link.
Units are the logical paths between remote peer systems. Each unit is a
subdivision of a session type and has a device associated with it. For an X.25,
SNAX/XF, or SNAX/CDF session type, the unit is a line. For a PTP (process-to-
process) session, the unit is a file name.
Each INMC link can have many different session types, each with many active units at
one time. Message traffic is distributed evenly over the available communications
paths so that no units are idle or overloaded in comparison to other units.
Link failure occurs when all units (or logical paths) to a remote peer have failed. All
data currently being sent is lost.
If a link fails, all NRD messages that originated from the remote system are
automatically deleted.
Units will try to reestablish communication with their remote peers. If the value of the
SESSMSG system parameter is YES, then every time an attempt to establish a
connection fails, another message is issued to all monitor-class operators. When one
unit receives an acknowledgment, the session is reestablished, and the status of the
link changes to ACTIVE.
If you were signed on to the remote system when the link failed, an automatic
SIGNON is issued on your behalf when the link recovers.