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

Expand Modifiers
Expand Configuration and Management Manual — 529522-013
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L4CONGCTRL_OFF/L4CONGCTRL_ON
The result of these algorithms is a one-hundredth of a second value.
For more information on the multipacket frame and variable packet size features, see
Section 17, Subsystem Description.
L4CONGCTRL_OFF/L4CONGCTRL_ON
Default: L4CONGCTRL_ON for Expand-over-IP and Expand-over-ATM lines
L4CONGCTRL_OFF for other line types and multi-line paths
Units: Not applicable
Range: ON or OFF
These path modifiers are applicable to all Expand line types. The L4CONGCTRL_ON
modifier enables the congestion control mechanism on the Expand node for sending
packets on a path. Congestion control mechanisms regulate system resources to avoid
network bottleneck and resource contention situations.
L4CONGCTRL is a path parameter and the path profile sets L4CONGCTRL_OFF
because it is shared by all line types. Therefore, multi-line IP paths default to
L4CONGCTRL_OFF and must specify L4CONGCTRL_ON.
The L4CONGCTRL_ON modifier is also recommended for Expand line-handler
processes that are part of a multi-CPU path.
You should read the description of the congestion control feature in Section 17,
Subsystem Description, before using this modifier.
L4CWNDCLAMP n
Default: 32767
Units: Integers
Range: 2000-2147483647
The path modifier is applicable to all Expand line types if the congestion control feature
is enabled (L4CONGCTRL_ON). It specifies the maximum value for the congestion
control transmit window. The packet rate transmitted over the path does not exceed the
L4CWNDCLAMP value. Expand uses a window scale factor of 5, for packet sequencing
and window values. To calculate the L4CWNDCLAMP value, use the following formula:
L4CWNDCLAMP = <Congestion_window_size_in_Bytes> / 32
Where,
<Congestion_window_size_in_Bytes> is size of the congestion window
Note. If you use the Expand subsystem SCF ALTER LINE command to set the L2TIMEOUT
modifier, you must convert the result of this algorithm to a time interval. For example, if the
result was 300 (3 seconds), you would enter this command:
AL
TER LINE $device_name, L2TIMEOUT 3.00.