Expand Configuration and Management Manual (H06.21+, J06.10+)

Subsystem Description
Expand Configuration and Management Manual — 529522-013
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Sending and Receiving Data
connect request. If you specify the MAXRECCONNECTS modifier, you can also
control what happens after the reconnect limit has been reached by specifying the
AFTERMAXRETRIES_PASSIVE or AFTERMAXRETRIES_DOWN modifier.
Passive Connect Request
When the Expand-over-NAM or Expand-over-ServerNet line-handler process issues a
passive connect request, the NAM waits for an incoming connect request. You can
cause the line-handler process to use the passive connect method by specifying the
CONNECTTYPE_PASSIVE modifier.
The passive connect request is successful when the NAM process receives a connect
request within a certain timeout period. After the passive connect request is successful,
the Expand-over-NAM or Expand-over-ServerNet line-handler process can begin
sending and receiving data over the connection.
If the connection request is not successful within the timeout period, the Expand-over-
NAM or Expand-over-ServerNet line-handler process will continue to issue passive
connect requests at regular intervals until a connect request is received.
The default connect timeout period is 60 seconds for Expand-over-ServerNet and 30
seconds for Expand-over-NAM line-handler processes. You can control the connect
timeout period with the Expand SCF TIMERRECONNECT attribute. (The
TIMERRECONNECT attribute does not correspond to an Expand modifier and can be
changed only by using the SCF interface to the Expand subsystem.)
You can limit the number of times the Expand-over-NAM or Expand-over-ServerNet
line-handler process will attempt a connect request by specifying the
MAXRECONNECTS modifier. If you specify MAXRECONNECTS, you can also control
what happens after the reconnect limit is reached by specifying the
AFTERMAXRETRIES_PASSIVE or AFTERMAXRETRIES_DOWN modifier.
Sending and Receiving Data
Specifying the TXWINDOW modifier enables you to control how many packets the
Expand-over-NAM or Expand-over-ServerNet line-handler process can send before
receiving acknowledgment from the NAM process. You can also control how many
packets the NAM process can send to the Expand-over-NAM or Expand-over-
ServerNet line-handler process before requiring acknowledgment by specifying the
RXWINDOW modifier.
After a connection is established, the Expand-over-NAM or Expand-over-ServerNet
line-handler process periodically probes the subdevice to which it is bound to ensure
that the line is still operational. If the line-handler process does not receive a response
to its probe within a certain timeout period, it will retry the probe a specified number of
times. If the retry limit is reached before a response is received, the line-handler
process will declare the connection inoperable.
You can set the probe frequency rate, timeout period, and retry limit using the Expand
SCF attributes TIMERINACTIVITY, TIMERPROBE, and RETRYPROBE.