Expand Configuration and Management Manual (H06.03+)

Tuning
Expand Configuration and Management Manual—529522-002
19-31
Example 2: Reducing Passthrough Traffic
Example 2: Reducing Passthrough Traffic
It is common for the role of a node in an Expand network to change over a period of
time. Example 19-7 shows a situation in which the routine, simple collection of
Measure SYSTEM entity data helped an operations staff discover that certain nodes in
the network had become switches—that is, their resources were used primarily for
passthrough traffic. Further investigation showed that the simple rerouting of
communications lines would help to recover some processor resources and free
controllers to be used elsewhere, perhaps in more stressed network paths.
Measuring Passthrough Traffic on a Single Node
Example 19-7 shows a summary of Measure SYSTEM entity data on a node called
\JUICE. The data was captured by Measure, placed in a structured file, and then
formatted with Enform.
The SYSTEM data allows you to compare the number of Expand frames transferred
between a node and its neighbors to those that are simply forwarded or passed
through to other nodes. Passthrough traffic is shown in the SENT-FWD and RCVD-
FWD counters. Total passthrough traffic is shown in the TOTAL FORWARD column.
Figure 19-6. Packet Size/Bandwidth Comparison
Bits per
message
0
5000
10000
15000
20000
256 1024 2048
Packet Size
(Bytes)
VST029.vsd