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Least cost routing with multiple route groups

Hi all

I have set up a solution of least cost routing using multiple route groups in a route list and a route filter pointing to that list. It works ok but I am wondering something about call failure on the WAN.

Using callmanager 6.1 and h323 gateways, the call will route as follows

1. route call out remote gateway

2. route call out local gateway

I am wondering what circumstances will cause 1 above to fail and let the call route by option 2.

The CallManager SRND states

Route Lists

A typical use of a route list is to specify two paths for a remote destination, where the first-choice path is across the IP WAN and the second-choice path is through the local PSTN gateways.

• Multiple route patterns may point to the same route list.

• A route list is a prioritized list of route groups that function as alternate paths to a given destination. For example, you can use a route list to provide least-cost routing, where the primary route group in the list offers a lower cost per call and the secondary route group is used only if the primary is unavailable due to an "all trunks busy" condition or insufficient IP WAN resources.

I'm wondering does "unsufficient IP WAN resources" mean the WAN is out of bandwidth? And will the method then work the same as AAR in the sense of CAC?

I hope my rambling makes some bit of sense!




Re: Least cost routing with multiple route groups

CUCM is not aware about bandwidth unless you add some sort of CAC. It can be location based returning "unsufficient IP WAN resources" use AAR if configured or another path - local gw. Another CAC option can be GK and with GK configured you don't have AAR available, so you can use local gw as another path.

Re: Least cost routing with multiple route groups

I was trying to come up with some similar. All my CUCM remote sites are routing out of CUCM to an H323 gateway. I tried to configure a Route Group with the h323 gateway in it, and it failed. If i use just the h323 gateway on the route pattern it worked fine.

I also tried to do a re-route through CSS/PT. So I had a Route Pattern 55-4000 that hit the H323 gateway. Then I create a Translation pattern in a different PT/CSS and ordered it lower in the calling search space. The translation pattern was 55-4000, but transformed the number to PSTN. No luck.

Find a work around or?