- Cisco WAN Modeling Tools User Guide

5-7
Cisco WAN Modeling Tools Guide
OL-10426-01, Rev. A0
Chapter 5 NMT Execute Commands
Optimize Command
The following tables describe how to troubleshoot problems with Execute commands.
Symptom
IGX Links are using more bandwidth than expected for voice and data
calls.
Probable
Causes
Voice and Data (TS and NTS) connections on the IGX are translated into
fast packets. When these 24 byte packets with 20 bytes of payload are
inserted into cells, the packet header is not removed, and either one or two
packets are inserted into the cell. The static administration load assumes
either one or two packets, based on the combine time-out value for the
particular type of connection.
Solution
Combine time-outs are network global parameters that can be configured
under Configure/Model Settings menu. The parameters are specified in
the units of 0.125 usec.
Set the combine time outs to the largest value possible to optimize
bandwidth usage in the model.
Symptom
Changing the Least Cost Weights does not effect the routes of the
connections.
Probable
Causes
CNF file may have preferred routes, or (if it was a CET extraction) it may
have actual routes. These route fields are checked first. If there is a route in
that field, the model will use it before running AutoRoute.
Solution
Remove the actual route, or the preferred route. This can be done using F6
in that field for each connection. Or you can remove all routes in the
CONFIG/UTILITIES/CLEAR DATA menu.
Also check the setting of Use Preferred Routes in the EXECUTE/SET menu.
If this flag is Y, preferred routes will try to be used first. If it is set to N, then
actual routes will be used first.
Symptom
Links have an unbalanced load when routed with AutoRoute.
Probable
Causes
The site table has a bundle field that routes a specified number of
connections at the same time in a bundle. the default number of connections
per bundle is 24.
Solution
Set the bundle field in the site table to 1.