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

Subsystem Description
Expand Configuration and Management Manual — 529522-013
17 - 51
Connection Establishment
The Expand-over-NAM or Expand-over-ServerNet line-handler process accesses a
subdevice by sending a bind request to the NAM process. A bind request is roughly
equivalent to an OPEN procedure. The Expand-over-NAM or Expand-over-ServerNet
line-handler process will continue to send bind requests to the NAM process at regular
intervals (default intervals are 60 seconds for Expand-over-ServerNet line-handler
processes and 30 seconds for Expand-over-NAM line-handler processes) until the
request is successful. There is no limit to the number of times the Expand-over-NAM or
Expand-over-ServerNet line-handler process can retry the bind request.
You can control the bind timeout period by setting the Expand SCF TIMERBIND
attribute. (The TIMERBIND attribute does not correspond to an Expand modifier and
can be changed only by using the SCF interface to the Expand subsystem.)
After the Expand-over-NAM or Expand-over-ServerNet line-handler process has
successfully bound to a subdevice, it tries to establish a connection through the NAM
process to a neighbor Expand line-handler process. There are two ways the Expand-
over-NAM or Expand-over-ServerNet line-handler process can attempt to establish a
call: active connect or passive connect.
The default connect method is active connect. You can cause the Expand-over-NAM or
Expand-over-ServerNet line-handler process to use the active connect method by
specifying the CONNECTTYPE_ACTIVEANDPASSIVE modifier.
Active Connect Request
When the Expand-over-NAM or Expand-over-ServerNet line-handler process issues an
active connect request, the NAM process tries to initiate a connection. If the 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 request is not successful within a certain timeout period, the Expand-over-NAM
or Expand-over-ServerNet line-handler process cancels the active connect request and
issues a passive connect request. When the NAM process receives a
passive
connect request
, it waits for an incoming connect request; this waiting period allows
the process to receive a connect request from a remote Expand-over-NAM or Expand-
over-ServerNet line-handler process.
If the passive connect request is not successful within the timeout period, the Expand-
over-NAM or Expand-over-ServerNet line-handler process will issue another active
connect request. The line-handler process will continue to alternately issue active and
passive connect requests until a request is successful.
The default connect timeout period is 60 seconds for Exp
and-over-ServerNet and 30
seconds for Expand-over-NAM line-handler processes. You can control the connect
timeout period by setting 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.)
Specifying the MAXRECONNECTS modifier enables you to limit the number of times
the Exp
and-over-NAM or Expand-over-ServerNet line-handler process will attempt a