Legacy Data System Reference - Comtech EF Data

12.2 HDLC and PASSTHRU Ports
12.2.1 Fallback speed
SE/PORT Configuration Parameters
Console SNMP Text-based Config
Fallback speed ifwanFallBackSpeed-bps,
ifwanFallBackSpeed-
Enable
[ifwan#] FallBackSpeedbps,
FallBackSpeed
Enable
For all user protocols except ASYNC and PASSTHRU.
Fallback speed for the transmitter. This parameter determines whether the port speed will
be reduced if congestion occurs on the WAN links.
Fallback is applied only if the port is set for DCE Internal clocking. For any other clocking
mode, the Fallback Speed setting is ignored.
Caution: If you disable fallback on a unit set for DCE Internal clocking, make
sure the transmission start level is properly set. Otherwise, data transmission
problems could occur. Refer to the description of the Transmission start level
parameter in SE/PORT/#/PVCR Configuration Parameters in the WAN/
Leased Lines module of this document series.
For NetPerformer models covered in this document series:
Set the Fallback Speed to ENABLE (the default value) to allow the NetPerformer to
automatically reduce the port speed when required. Set Fallback Speed to DISABLE to
prevent fallback on the port.
NOTE: The Dual Serial interface card for the SDM-9360, SDM-9380 and SDM-9585
does not support Fallback.
For legacy NetPerformer models:
Select a bit rate that is lower than the value of the Port Speed parameter. As a rule of
thumb, the fallback speed should be one half of the sum of the speeds of all links to the
destination unit. Set this parameter to 0 to disable fallback.
The range of values given below represents the minimum and maximum fallback speeds
possible. Some protocols cannot run at the maximum speeds. For these, you must select an
appropriate lower value.
For NetPerformer models covered in Values: DISABLE, ENABLE
this manual:
Default: ENABLE
For legacy NetPerformer models: Values: 0 - 2000000
Default: 2400
Memotec Inc. 12-5