Video Call

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Jan 9th, 2008
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Hi all.

We have a cisco 2851 with a VWIC-2MFT-E1 interface and 2 pvdm2 64. We have also a sony video station registerd (sccp) on our Callmanager (4.2).

We are trying to receive a video call from a remote H320 video station.

A show voice call summary on our 2851, shows both primary and secondary call connected.

Our internal Video station shows a "voice only" call.

My question....

How can I use our 2851 to get a working video call?

Thank you in advance


Carlo Poggiarelli

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Carlo Poggiarelli Tue, 02/12/2008 - 00:33
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I solved my problem upgrading the IOS of my 2851 to 12.4(15)T1.

The configuration showed at the link above is very similar to mine.



rajesh.kumar Sat, 03/08/2008 - 00:58
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did you try with dynamic secondary channel establish with primary video call.

For me requirement is accept video call from any source, my VG should provide secondary channel to other end dynamically.

Pls. let me know if you have any working confiuration of the same.


shoaib.usmani Wed, 07/29/2009 - 04:06
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Glad that you resolved the issue! I have a question and that'll be great if you could help me here. I am bit confused about the inbound and outbound numbers that are used for secondary call. You have put 6xxxxxxx for both incoming and outgoing, do thay have to be valid ISDN DDI and do they need to be assigned to any physical device? If you could explain this bit in a little detail, that'll be fantastic!

Thanks in advance.


Nicholas Matthews Wed, 07/29/2009 - 05:02
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Hi Shoaib,

The numbers in the pool will be right justified against the first number.

Meaning if your pool is:



And you dial 919-555-0000, your secondary numbers should come out to be 919-555-1111, etc.



shoaib.usmani Wed, 07/29/2009 - 06:11
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Hi Nick,

Thanks for your reply. So if a PSTN caller calls me for a video call on 919-555-0000 and the secondary numbers comes 919-555-1111, do both of these number have to be ISDN DDIs? If I assign 919-555-0000 to my video end point e.g. 7985 phone, then where 919-555-1111 number will be assigned to?

My question in summary: All the number in the pool, where do they come from? Do we use DDI's or can ramdomly pick any range?

Many thanks,


Nicholas Matthews Wed, 07/29/2009 - 08:19
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Depending on the endpoint, you can have the secondary numbers be the same as the primary. But whatever you advertise as the secondary, whether they are unique numbers or not, will need to be DDI.


shoaib.usmani Wed, 07/29/2009 - 08:29
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Thanks Nick,

Let me give it a go and see if that works.



shoaib.usmani Wed, 07/29/2009 - 13:17
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Hi Carlo,

Thanks very much for this info. I have two questions here for you:

1. What are your H.323 video endpoints in your network? i.e. Where is your dial-peer 9998 is sending IP calls to?

2. Looking at your config, you have voice class called number pool 44 as below

voice class called number pool 44

index 1 727085 - 727099

Could you please tell me where did you get this range from? Are they valid DDIs or any random numbers? Or number assigned to your IP phones.

If you have any network diagram or topology for your solution, that'll be really great!

Many thanks,


Carlo Poggiarelli Wed, 07/29/2009 - 14:02
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Hi Shoaib

As you can see on my config, my gayeway is registered with a gatekeeper in the same way of my videstation (tandberg)

So dialpeer 9998 is sending ras requests to the gatekeeper.

727085 ,for example, is the number that my videstation uses to register with GK.

727085 - 727099 is the number range that external VS will use to bring up secondary calls

Last (but not leat :) They are not valid DID but the are translated from rule 727.

Here is my network scheme.



shoaib.usmani Wed, 07/29/2009 - 14:25
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You are a star!!! This post has made my life much easier.. I have one final question and then I will let you go. You have 3 video endpoints 727085, 86 and 87 but in the voice class pool you have given the end numebr to be 727099, may I ask what are the numbers from 727088-727099? Are they assigned to any devices? If not then how the secondary call will use these number to connect to your video endpoint?

Thanks in advance!


Carlo Poggiarelli Wed, 07/29/2009 - 23:59
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Hi Shoaib.

I've reverved this pool for to reasons.

One is for future VS and the other is, as Nick told, because when an external VS calls mine, it may need a sequential number to bring up secondary calls. In this case we can say each number of 727088-727099 range is an isdn b channel that external vs will use to reach the desired (and the available at the remote site) bandwidth for video calls.

In this document cisco explains the h320 video call flow.Check it and the situation sould be more clear.





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