[cisco-voip] Polycom Video integrated to Cisco

[Robert Kulagowski]

Malcolm Caldwell wrote:
> On Wed, 2008-09-03 at 09:13 -0500, Philip Walenta wrote:
>> To support video through an IOS device requires some unique dial
>> peers.  Have a look at this document:
>>  
>> http://www.cisco.com/en/US/docs/ios/12_4t/12_4t11/h320gw.html
> 
> Just a quick note: prior to 12.4(20)T using this feature effectively
> limits you to 128K calls because there was no support for bonding.
> 
> Older versions of IOS (<12.4(20)T) did allow >128K calls using H.221.
> In H.221 you need to establish multiple channels using secondary
> numbers.  These version of IOS allowed the negotiation of these
> secondary numbers via h242, but none of the common endpoints support
> h242.  So you must manually configure the secondary numbers.  For
> Outgoing calls you do this on the endpoint: common endpoints only have
> room for two numbers (primary and secondary) limiting you to 128k.  For
> incoming calls the situation is worse: you must configure the secondary
> numbers on the gateway.
> 
> So, using common endpoints you are limited to 128K outbound and setting
> up secondary numbers in the IOS config for outbound.
> 
> All is not lost. Bonding was added to 12.4(20)T: 
> http://www.cisco.com/en/US/docs/video/milticomm/h320Bonding.html
> 
> Bonding is the standard 
> 
> I found all this out the hard way.  Although the limitations are
> documented it was not apparent until I actually tried this what
> "ISO-13871 bonding is not supported for H.320" actually meant. 
> 
> I have not yet tried 12.4(20)T and bonding yet, but I am hopeful it will
> work.

Yeesh; complicated.

So, given a HDX 4002, connected via ethernet, it looks like you're 
restricted to 1024K, correct?

Currently, we've got some Codian 3241's that are PRI gateways and also 
have gatekeepers built-in.

If the channel bonding can be made to work, then would you try to run a 
GK train on each 2851 (so that local video systems register locally, and 
can therefore still function if the WAN is out?)  Or do you just 
statically assign using the session target command?

I'm also trying to understand the requirement for secondary numbers.  On 
the Codian, I don't define secondary numbers, so each incoming call 
comes to the same DID and the Codian aggregates them (I'm assuming that 
channels 2-n are negotiated 'Hey, inbound caller, next channel is on DID 
{foo}').  Is this document telling me that I need to setup a pool of 
"extra" numbers which are then sent to the caller?  If my DID is 
312-555-1212, do I need to do a range (say 312-555-1220 to 1250 as well?)

The documentation gives you that "You're in a twisty maze of passages, 
all alike." feeling!