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ISDN PRI Primary D Channel and Backup D channel 2

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calhoony

Technical User
Oct 14, 2003
118
US
Can you have Primary and backup D Chanels in CCM 4.1? We have an Avaya G3R today and have a big trunk group that has multiple PRI's. We have a primary and a back up D Channel and then on the rest of the PRI's we can use all of the channels. The question is can I do that in CallManager?
 
Callmanager really isn't going to care. The real question you want to know is, can Cisco routers handle a backup D Channel since Callmanager would depend on the gateway to place and receive the calls. The AS5xxx series is what you want to use to terminate your calls to the PSTN. It supports a backup d channel. Here is a referance to it on Cisco's website.



The AS5xxx series of access gateways can do true switching and terminate many PRIs. Which one you need depends on how many PRIs you will terminate.


It is what it is!!
__________________________________
A+, Net+, I-Net+, Certified Web Master, MCP, MCSA, MCSE, CCNA, CCDA, and few others (I got bored one day)
 
Thanks computerhighguy, So I would have to use an AS5XXX as my gateway...couldn't use a 26XX router?
 
You probably won't want to do that. It really depends on what you want to do and what features you want to deploy. The 2600 series is a router first and a voice platform second. The AS series is a voice/dialing platform first and a router second. The 2600 series cannot do true PRI switching which, in my case, is not a good thing. Especially when connecting external PRI devices (like conference bridges,etc), the 2600 series will not work well. The AS series can do true PRI switching and has a lot of control over the channels.

Here is how I usually recommend gateways.


If you are using a couple of T1s or a single PRI coming into your CCM landscape, then the 2600 series is good. The smaller series will work also.

If you are using more than 1 PRI or have several systems to connect to (i had a legacy PBX and the new CCM landscape to connect to), then I would recommend the AS5350 or better.


We had a 3640 with a couple of PRI cards and it just couldn't switch the PRI channels between the different systems. The AS5350 is a much better platform and can terminate voice and remote dialin on the same platform.


It is what it is!!
__________________________________
A+, Net+, I-Net+, Certified Web Master, MCP, MCSA, MCSE, CCNA, CCDA, and few others (I got bored one day)
 
Calhoony,
Your question is a little vague. So this is what I think you are really asking.

Does CCM support NFAS with backup d channel support across your PRI trunk group connecting to your G3.

The direct answer to this is NO!! CCM does not support NFAS in any way. MGCP does not have any concept of this also. And using MGCP backhaul support will not eliminate this problem either. CCM basically does not provide this function. :(

Now for the good news as (as computerhighguy) stated you could use are voice gateway/router to handle this. BUt you need to realize here is that the VOICE GATEWAY is providing all PRI functions here. NOT CCM. You will need to use H323 to connect from your Voice gateway to CCM. CCM Now knows nothing about the PRi and is just recieving a VOIP call from the gateway.

Could you Use a 2600? From what you described I would say yes.(Nothing that computerhighguy said is wrong I just don't see you needing tandem switching(true Pri voice switching) here. If you are only connecting ONE PBX to the gateway then a router platform is fine for your PRI trunks.

For a small amount of call you could even connect multiple PBX to the 2600 and let CCM route the calls between trunk lines for you. I would not recommend that for High density PRI applications but I don't think that is what you have.

Good luck.
 
ccmuser,
I should have been a little more clear. What I needed to know if I replace my G3R with a Cisco CallManager will I be able to connect all of my PRI's I currently have today in My G3R to the CCM via a gateway/router...in my G3R I have several ISDN PRI's which have primary and backup D channels. If Cisco can't handle that I need to know now before we make a big mistake....
 
Can Cisco handle what you want to do?

YES!

I want you to keep in mind the underlying technology with VoIP is the network. CCM is, typically, a distributed architecture much like your typical corporate network (there are exceptions like when you use the PCI card for terminating your PRI). You have switches, routers, access points, etc. You traditional phone system is not, typically, a distributed architecture. Everything is housed in one or two boxes. Please don't get distributed mixed up with modular.

CCM supports some different gateways. For some reason, people like MGCP. Don't get me wrong, it has it's place especially in large configurations where CCM needs to know the state of all the channels, but I feel that it is a bit over rated for your typical SMB installation.

I prefer, and once again this is me, to use H323 gateways. And I use quite a few depending on how big the installation is and how many external devices have to get conencted (voice call boxes, overhead paging etc).

For your setup you would have to use your Cisco router as an H323 gateway. No big deal. In fact, I feel you get more control and ease of administration using an H323 gateway (such as redirecting inbound DID numbers). CCM will just accept incoming calls from it or pass off outbound calls to it. In fact, you don't even have to use a Cisco router for this. You can use any H323 compliant gateway that supports what you want to do. I wouldn't suggest going with another vendor, but that is an option.

Do some searches on Cisco website for what you want to do. Check to make sure that the 2600 series supports what you want to do feature wise and head CCMUser's advice. He is a pretty bright individual.


It is what it is!!
__________________________________
A+, Net+, I-Net+, Certified Web Master, MCP, MCSA, MCSE, CCNA, CCDA, and few others (I got bored one day)
 
AHH that is a little clearer.. You are not looking to connect the G3 to callmanager. You are looking to replace the G3 with Cisco call manager. Well this all comes down to port density and how much saving you realize from NFAS signalling. AS computerhighguy stated, MGCP seems to pretty popular these days. Overall I like the simplicity it provides and the abstaction it gives to the non-Telco savvy user. The problem is D channel cost in large installs.

As stated before you still really have two options.

Option 1.

MGCP gateway. IE cisco 2600,2800,3800, even 1700. In MGCP Call manager will in essence control the PRI's but you do not have the capability for a NFAS or a backup D channel. YOU WOULD HAVE TO ORDER NEW PRI's to do this. That may not be a bad IDEA..

This gives a testing window to run both systems side by side. Then on your cutover day just transer all your DID's. ( I really like this approach with an MGCP solution, 323 solution, or even a traditional voice switch.)

Option 2a Router platform running IOS. Provide NFAS funtions, hence backup d-channel support. The problem as computerhighguy pointed out is this platform does not provide any true voice switching.(circ switched voice).
I tend to think you are not needing this funtion though.

Option 2b. Cisco 5400 A true voice platform switch from cisco. Offers voice switching. And some other neat features like IVR funtions. If you planning on growing this is way to go.. BUT COST is an issue.

Option 2c. H323 blackbox. Ie any thirdparty PRI to h323 gateway.

Personally I would go with option 2a if you are only connection to one PBX(call manager) You can leverage excicting equipment and throw you PRI cards in your data routers if you have voice capable routers. 37 or 3800 being the ideal cheaper platform here.

You could go 1a and use MGCP in many regions ording two pri's with seperate dchannels and letting telco hunt between them is not that much more expensive.. I just don't like as much.

Good luck again
 
ComputerHighGuy -

I agree with your division of H323 and MGCP but I'm curious how you handle 2-line callerid with H323 on the CCM platform. My understanding and work with it on the Cisco 17xx/26xx/36xx platforms has been that H323 can not (yet) deliver the 2line format where MGCP w/CCM does support it. I've run into this issue in a number of upgrade/installation projects. Do you just deliver the single line callerid or how do you handle it? Thanks.
 
Caller ID Caller ID Caller ID

This is always a sore point with me. So here is the information you need to know about CCM, caller ID and PRIs.

How you typically get your caller ID
Number: Display i
Name: Facility i

These are the parts of the call setup on your D channel.

In order to get name and number caller ID into CCM, you need both name and number in the display i part of the call setup. Most phone providers do no like to do this (or can't even when they promise you up and down before you sign the paper work that you can, just to find out the day after cut over that they cannot or will not. I hate XO communications). Cisco swears up and down that they will change this in a later release and that they are working hard to do major improvements and keep the system stable. I run 4.1(2) and this feature is not in it. The systems is extremely stable, but I don't get caller ID name.

So you have a couple of choices.

1) Get your PSTN to send everything in the Display i part of the call setup.

2) Wait until Cisco adds Facility i support for Caller ID name.



It is what it is!!
__________________________________
A+, Net+, I-Net+, Certified Web Master, MCP, MCSA, MCSE, CCNA, CCDA, and few others (I got bored one day)
 
BNAvoip2

Just to clafify are you talking about q.931 IE delivery(Bellcore GR-1367-CORE)?

If that is the case you need to throw a gatekeeper in the middle of your call. The reason you need to do this is that IE delivery over H.323 in CCM is only supported via intercluster trunks. IOS alone gives no support for a Raw intercluster trunk and must rely on a gatekeeper to create the intercluster trunk.

You could also get cute and use TCl to gather IE info. You can then push direct to phone VIA XML or push dirct to PC via screen pop.
 
OH BTW.. That being said..I don't think anyone bothers to do the gatekeeper implementation. Mostly cause Cisco insists they will fix this "problem"in the near future.

I do know of some clients that are useing TCl for this though..
 
computerhighguy ,

I think we posted at the same time. Just to clarify. (and I think this is what you meant just want to make sure)
And I made a typo.

Cisco does support Facilty Ie delivery but only Via MGCP. Facility IE is Bellcore GR-1367-CORE. I mixed the numbers up in my original post on this topic and posted that is Display ie.

Cisco will also support iso based Q.sig at the MGCP level.

So pretty much computerhighguy is right on about this one. IF you want H.323 you need to have your provider push all info via display IE at this time.

Or use MGCP. I have use a Cat6000 with the 6608 blades for this and it has worked OK.
 
CCMUser,
As I am sure you can tell, I am not a phone guy, but rather a networking guy. I did not know that MGCP supports the facility I caller ID name. Thanks for the update. I appreciate all the information you put into this group.


It is what it is!!
__________________________________
A+, Net+, I-Net+, Certified Web Master, MCP, MCSA, MCSE, CCNA, CCDA, and few others (I got bored one day)
 
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