LRG when branch has two companies/carriers

[Isai Reyes]

Hello!

I´m facing kind of a complex situation and came here to ask you guys for advice.

Here is the situation:

New CUCM deployment using centralized architecture; CUCM cluster is in HQ and there are branches distributed in a geographical space.

Branches use an ISR with FXO PSTN access, and in some of those branches there are two companies, let´s call them Company A and Company B, and each of those companies has their own lines for PSTN access. Also in CUCM each company has their own device pool (DP).

I know that in CUCM is possible to use a standard local route group (LRG) in order to simplify call routing but let´s say I configure a set of 11 route patterns, and I use LRG feature. CUCM will route calls to ISR located at branch but how will know ISR what FXO lines use for each company?????? I´ve been thinking in use some kind of sip uri manipulation in ISR (since each company has a different extension number range) or using a Called Party Transformation Pattern in CUCM but I don´t see this feasible.

Also I know that in CUCM Route List (RL) I can specify a prefix for outgoing calls, but it is not possible to add a RL at DP level and even if this were possible I´m not sure that two RL can use same ISR and prefix different prefixes (one for each company)

BTW: I´m using a SIP Trunk from CUCM to those ISRs but if the solution needs to change this I could change it to H.323.

I´d appreciate your advice

Thank you!

[Kita]

I'm not sure this can be accomplished with SLRG because Company A and Company B will ultimately point to the same SIP trunk....so no real distinction coming into your VG.

What about 2 route patterns:

9.[2-9]xx[2-9]xxxxxx in companyA-pt associated device is the VG; strip preDot; prefix 444
9.[2-9]xx[2-9]xxxxxx in companyB-pt associated device is the VG; strip preDot; prefix 555

Now you have different digits coming into the VG and you should be able to use trunk groups and translation profiles to further manipulate the digits and get them sent out the right ports.

Disclamer: I haven't tested this...just thinking through in my head

[Isai Reyes]

Hi Kita

Thank you for your comment :)
I haven´t tried your approach but I think it may work.
After thinking about it a little bit and asking some co workers I decided to use MGCP to control those FXO ports from CUCM. I´ve seen this worked before but I didn´t remember

[Jonathan Schulenberg]

If the two companies have different extension ranges, you could use this to match different incoming dial-peers on the gateway. From there you could use COR/LPCOR to restrict which outgoing dial-peers can be matched.

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/configuration/cube-book/voi-inbnd-dp-match-uri.html

I usually match the host portion of the VIA header but that wouldn’t work here. You would want to match based on the user/LHS of the From and Diversion header (to cover SNR scenarios). Of course this would warrant a fair amount of testing to ensure every call scenario matches the intended incoming VOIP dial-peer.