Timing parameters

You can make timing adjustments through the parameters of the Systems Network Architecture (SNA) controller description.

SNA controller descriptions (advanced program-to-program communication (APPC), SNA host, remote workstation, finance, and retail) have parameters that describe the behavior of the station. The parameters can be used with all LAN protocols. The names of these parameters begin with the letters LAN.

The table below shows the LAN parameters and their default values (see the *CALC column). You can view all parameter values with the Display Controller Description (DSPCTLD) command when the controller is varied on. You can find how a parameter affects your connection's performance by clicking on the link that is in the table below.

Note: Reducing a parameter's value gives you quicker error detection, but it also reduces the time for error recovery.

To change these parameters, see Change timing parameters.

Parameter	Description	*CALC value
LANCNNTMR	(LAN connection timer) The time to wait between requests to connect.	7 seconds
LANCNNRTY	(LAN connection retry) The number of times to poll for request to connect.	10
LANRSPTMR	(LAN response timer) The time to wait before retransmitting a frame.	1 second
LANFRMRTY	(LAN frame retry) The number of times to retransmit a frame.	10
LANACKTMR	(LAN acknowledge timer) The time to wait before sending an acknowledgment.	0.1 seconds
LANACKFRQ	(LAN acknowledgment frequency) The number of frames to receive before sending an acknowledgment.	1
LANINACTMR	(LAN inactivity timer) The time to wait before requesting a response from the remote station.	10 seconds
LANMAXOUT	(LAN maximum outstanding) The number of outstanding frames allowed before requesting an acknowledgment from the remote station.	2
LANWDWSTP	(LAN window step) An alternative to LANMAXOUT. Use LANWDWSTP to help alleviate network congestion.	*NONE
LANACCPTY	(LAN access priority) The priority of the station. Stations with higher priority have greater access to the token. (Used for token-ring only.)	0

The LANCNNTMR and LANCNNRTY parameters
Your Systems Network Architecture (SNA) controller description has two parameters: LAN connection timer (LANCNNTMR) and LAN connection retry (LANCNNRTY). They work together to define the frequency and persistence of polling the remote station to establish a connection.
The LANRSPTMR and LANFRMRTY parameters
In your Systems Network Architecture (SNA) controller description, the LAN response timer (LANRSPTMR) and the LAN frame retry (LANFRMRTY) parameters work together to determine how soon and how often the system retransmits a frame.
The LANACKTMR and LANACKFRQ parameters
Your Systems Network Architecture (SNA) controller description includes the LAN acknowledgment timer (LANACKTMR) and the LAN acknowledgment frequency (LANACKFRQ) parameters. They work together to determine how often to send an acknowledgment to the remote station.
The LANINACTMR parameter
The LAN inactivity timer (LANINACTMR) parameter of your Systems Network Architecture (SNA) controller description determines how long your system waits before requesting a response from the remote station. Your system uses the request to test if the remote station is still accessible.
The LANMAXOUT parameter
The Maximum outstanding data frames (LANMAXOUT) parameter of your Systems Network Architecture (SNA) controller description specifies how many frames your system sends before waiting to receive an acknowledgment.
The LANWDWSTP parameter
The LAN window step (LANWDWSTP) parameter of your Systems Network Architecture (SNA) controller description determines whether the number of outstanding frames are reduced during network congestion.
The LANACCPTY parameter
The LAN access priority (LANACCPTY) parameter of your Systems Network Architecture (SNA) controller description determines a token's priority.

Parent topic: Timing