Locations Links on CUCM 9.x

[Johnny Nkunda Kabundi]

Hi there,

I have a client who has an Head Office and two branches (BR1 and BR2). These sites connect to each other using MPLS. Head Office has 512 Kbps link into the MPLS Cloud and BR1 has 128 Kbps into the MPLS Cloud and BR2 has 128 Kbps into the MPLS Cloud.

When HQ means calls to BR1 or BR2, the amount of bandwidth using G.729 codec should be deducted from the 512 Kbps, so is the same for BR1/BR2 when they make calls over the WAN. The bandwidth should be deducted from the 128 Kbps.

On CUCM 9.x, when I setup locations Links between HQ and BR1 = 512 Kbps and HQ and BR2 = 512 Kbps. When I make a call from HQ to BR1, I can see that there is 24 Kbps deducted from the 512 Kbps that HQ has but I can still see that there is 512 Kbps available when I check the location topology between HQ and BR2.

I would like to set up the locations links in such a way that when HQ makes calls to either BR1 or BR2, the amount of BW should be deducted from the total of 512 Kbps. How can I achieve that on CUCM 9.x?

This used to be easy in CUCM 8.x where you simply setup a Location and allocate the amount of Audio BW.

Warm regards,

Johnny Kabundi.

[Jaime Valencia]

You simply can't do that, the system is working as expected, what you're actually telling the system with your config is that you have a whole 512 kbps to EACH SITE, and the BW deduction is done PER site.

If you configured a hub and spoke, and set HQ as hub, when you call from BR1 to BR2, the config would deduct from both links as you're using them both.

But there is no way to deduct from BR2 if you call from HW to BR1

[Jonathan Schulenberg · Accepted solution]

If I'm reading the description correctly you just need to change where you build the links:

Link 1: HQ to Hub_None = 512kbps

Link 2: BR1 to Hub_None = 128kbps

Link 3: BR2 to Hub_None = 128kbps

if Hub_None doesn't exist, just create a site and name it Hub_None, or whatever you want really. The name has no special significance anymore as the links define the logical topology.

Lastly, remember that CUCM ELCAC only counts packet size down to layer three, not including the layer two overhead. Example: CUCM would deduct 80kbps for a G.711 call but it would actually consume 95.2 if the layer two frame is Ethernet. Make sure this distinction is accurately reflected between CUCM and your IOS policy-maps.

[Johnny Nkunda Kabundi]

Hi Jonathan,

I would like to thank you so much for your post. 5 STARS !!!

You have saved my life !!! I have done exactly what you said in my lab and everything is working perfectly.

Hub_None does the magic. I do now finally have a solution for all my clients that connect their sites using a single connection into the MPLS or Metro Ethernet Cloud.

Problem resolved :) !!!

Johnny Kabundi.