LANRSPTMR and LANFRMRTY

The LAN response timer (LANRSPTMR) and the LAN frame retry (LANFRMRTY) parameters in your controller description determine how soon and how often the system retransmits a frame.

LANRSPTMR defines how long to wait before retransmitting a frame to the remote station. LANFRMRTY specifies how many times to retransmit a frame. A system retransmits a frame when one of the following occurs:

A frame was lost or damaged.
The remote station does not respond because it is busy.
The remote station is waiting to acknowledge the frame with an information frame of its own. (See LANACKTMR and LANACKFRQ for more information about the acknowledge timer).

After your system retransmits a frame a number of times (based on the number that is indicated by the LANFRMRTY parameter), the system notifies the user that an error occurred and disconnects itself from the remote station.

The default *CALC value for LANRSPTMR is 1 second. The default *CALC value for LANFRMRTY is 10.

Performance considerations:

The default values of the parameters are designed for a single LAN and can cause too many frame retransmissions when accessing a remote station through a remote bridge. The bridge might slow data traffic enough that your retransmit timer expires before the remote station's acknowledgment reaches you. Eventually, your system will automatically disconnect itself because it retransmitted a frame too many times. If this is the case, you should increase the values of LANRSPTMR and LANFRMRTY.

Note: If you make the parameter values too large, your connection failure notices can be delayed.