Problem with Polycom endpoint dial string via VCS

[readamson]

Greetings,

I have an environment currently using a set of standalone Polycom endpoints (mixture of VSX/HDX units).  We recently installed VCS-c / VCS-e / TMS and despite some problems with SIP registration on some of the older endpoints and management support via TMS, everything is working well.  The only remaining problem at this point is that there are a number of business partners making use of extensions in their H.323 dialing strings which works fine from the Polycoms when not using VCS-c as a gatekeeper in the dial format of <IP address>##<extension>.  When using this same dial string and the endpoints are registered to VCS-c then the only thing noted in the call history is a dialed number of <extension> which fails.

I am aware that different manufacturers have historically handled extension dialing differently since the days of ISDN only and has apparently perpetuated to present day.  However, this is a pretty critical need still at this point and I am looking for input as to whether or not VCS supports the use of extension dialing in the dial string (or is it only after the call is connected to whatever gateway is hosting).  If it does, is there a specific format to this dial string that both the Polycom endpoints can support, and that VCS can interpret correctly?  Does anyone have this working currently?

Latest versions of software are on all components.

Thank you in advance for any thoughts you may have!

[ahmashar · Accepted solution]

Hi Readamson,

using the "device-IP-address##extension" syntax for dialing an H323 device is  not a standards-based way of doing things, this is Polycom's approach to  extension dialling which the VCS does not understand without modifying  the alias to an 'Extension@IP' format.

Assuming  that the device-IP-address receives the H225 SETUP message from the  VCS-E, what does it do with the SETUP message? Is there a way which you  can configure this far end device to strip off the '@device-IP-address'  portion of the dialled number and route the call to the extension?

check this link:

https://supportforums.cisco.com/thread/2129307

regards, Ahmad

[readamson]

Thanks for the response Ahmad.  That post does indeed appear to match my issue.  I think I follow the logic in that thread, the problem of course being that we don't have control over the far end so it will take some time to work with every partner to figure out exactly what they would expect to receive if we are manipulating the sent digit string.

Bob

[Jens Didriksen · Accepted solution]

IP_address##Alias is Polycom proprietary format, the standard is H.323 Annex O which specifies Alias@domain, however Alias@VCS-E_IP_address can also be used.

If the end-points of your partners are registered to something like a VBP, then they need to configure their VBP to use Annex O as well as the proprietary format - or you can try the solution in the thread posted by Ahmad - however, your partners should still at least try to comply with the standards IMO.

/jens

Please rate replies and mark question(s) as "Answered" if applicable.

[readamson]

Thanks for the information Jens.  I think we are going to pursue this option as one of our resolution paths, hopefully the current configurations are old enough that the partners in question have updated somewhat and will support the Annex O format now and we just didn't know because nobody asked the question.  I would much rather have this than have to setup a new neighbor zone and custom search rules for each and every endpoint that requires the ##extension format.

Bob