Envoy ACP/XF Configuration and Management Manual

WAN Subsystem Profiles and Modifiers for
EnvoyACP/XF
EnvoyACP/XF Configuration and Management Manual—429232-003
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Optional Modifier Descriptions
The default value of the RNRTIMER is zero. When the value is zero, EnvoyACP/XF
allows the RNR state to persist (no error condition is reported). A zero value has the
same effect on both the local RNR state (caused by local buffer depletion) and the
remote RNR state (receipt of an RNR from a remote station).
When the value is not equal to zero, a timer is started using the value specified. If the
RNR state clears before the timer expires, the station resumes normal operation and
remains in Information Transfer State (ITS).
If the RNR state does not clear prior to the expiration of the timer, the station takes a
series of actions. The actions vary somewhat depending on whether the condition is a
remote RNR state or a local RNR state, as described below.
Remote RNR State
When RNR is received from a remote station and the RNR state does not clear before
the RNRTIMER expires, the following actions occur:
1. All pending application WRITE requests for the station complete with Guardian file-
system error 163 (RNR received).
2. Further WRITE requests for the transmission of numbered frames received from
the application for the station are completed with Guardian file-system error 164
(Disconnected).
3. EnvoyACP/XF takes the actions necessary to disconnect the station and prepares
the station to enter LDS.
4. The station enters LDS.
Local RNR State
When the RNR state is caused by local buffer depletion and the RNR state does not
clears before the RNRTIMER expires, the following actions occur:
1. All pending application WRITE requests for the station are completed with
Guardian file-system error 163 (RNR sent).
2. Further WRITE requests for the transmission of numbered frames received from
the application for the station are completed with Guardian file-system error 164
(Disconnected).
Note. The RNRTIMER value is specified on a line basis. However, the effect of the timer varies
depending on whether the condition has been caused by buffer depletion (local RNR state) or
by the receipt of RNR from the remote station (remote RNR state). When a local buffer
depletion condition occurs, the timer is applied to the line (all stations). When RNR is received
from a remote station, the timer is applied only to the station that sent the RNR.