Multiple PRI configuration - Two PRI inbound one PRI outbound

[bberry]

Hello all,

I am trying to find a configuration guide or something to assist with setting up a new location on Cisco UC as part of their relocation utilizing multiple PRIs. We are in the process of standing up a new office and have gotten stuck on the fact they will be utilizing multiple PRIs for phone service. We have several locations that have single PRIs and they are working fine but this will be our first multi-PRI. Here is what has been ordered for phone service.

1- two Foreign Exchange PRIs to handle all inbound and local outbound calls. This is so that we can move existing extensions to a different CO.

2- one LD PRI for all long distance calls.

First and biggest question is how do I configure the NIM-4MFT-T1/E1 card to handle multiple PRIs like this. I have two groups the way that I see it. One for the Foreign Exchange PRIs and a second one for the LD PRI. How do I create this setup. It looks like I do not have a group designated for the PRI like I do for data T1s with this card. I do have channels go active when I issue the PRI-group command but am thinking this just adds to a single group.

Secondly. There is a spot on the order details form asking about utilizing low to high or high to low which I figure is related to how out bound calls are made. I figure it really does not matter on the single LD PRI but does on the multi-PRI part. I so far have not seen anything in Call Manager to assist with telling calls how to flow for low to high or high to low.

I am sure as I begin to go through this I will have more questions but this is a good starting point. Like why do I still receive messages about DSP resources when router reloads even though I have a 256 PVDM on the 4-port T1 card and a 64 PVDM on the mother board. I have learned that the T1 card ONLY uses the PVDM actually on the card when we had the 64 PVDM there and could not even configure all four T1 ports.

Thanks in advance ...

Brent

[mikeleebrla]

I think you might be overthinking this. The only real concern with multiple PRIs is the clocking. With the older 2900/3900 routers the clocking "domain" was per router which could cause issues if you needed to sync clocks with multiple carriers, however with the 4000s it is per NIM so you have more flexibility. Each NIM can independently sync with a clock source. See link below for documentation of this.

https://www.cisco.com/c/en/us/td/docs/routers/access/interfaces/NIM/software/configuration/guide/4gen-t1-e1-nim-guide.html

"In Cisco 4000 Series ISRs, the NIM module can be its own clock domain if no network-clock synchronization participate command is configured for that NIM module. On a single NIM, all the T1/E1 lines with voice ports should share the same clock source on the remote side."

Regarding the low-high vs high-low channel selection, if you are using MGCP, then in CUCM look for the "Channel Selection Order" section. This determines how CUCM will send outbound calls to your carrier. The default is Bottom-Up as it should be since carriers usually send inbound calls to the top first. This way inbound is on the top and outbound is on the bottom.  Since you have multiple PRIs it really just depends on how you want to use the PRIs and load balance them. 

[bberry]

Thanks .. We just sat back down with management and the telco engineers and are now going with two PRIs. Inbound will be top down by the telco and outbound will be bottom up by us. We will use both D channels with one being primary and one being secondary.

[Monte Young]

Can you share your final configuration, specifically controller and dial-peers?