Testing a Polycom V2IU Firewall Traversal Unit

If you’ve been reading this blog, you know that I have 35 new Polycom VSX7000’s getting installed in 13 of my districts this summer. Of course we’re running into fun firewall challenges. In two of the districts, we have been unsuccessful at getting H323 to work through a Watchguard firewall. Changing the firewall isn’t an option. So I’ve been looking at the Polycom V2IU as a possibile solution. But I was very nervous about the dialing scheme required with any firewall traversal unit. The V2IU has an external IP address, and all the Polycom endpoints behind it have extensions. I haven’t been thrilled with my extension dialing experiences in the past, so I wanted to try this out to see what it could do. I made a list of all the tests I wanted to see working. Here’s the results.

V2IU Configured with Embedded Gatekeeper
First we (my district technology coordinator, me, and Cliff John from Polycom) set up the V2IU beside their firewall at the public/private border. We had a Polycom H323 Viewstation behind it, registered to the V2IU as the gatekeeper.

  1. Dial out to Polycom endpoint. Called out to my Polycom VSX 7000 (public IP). Worked great.
  2. Dial in from Polycom endpoint. My Polycom called in (using the extension box on the top right). Worked great.
  3. Dial out to Tandberg endpoint. Called a Tandberg MXP 880 (public IP) with no problem.
  4. Dial in from Tandberg endpoint. The Tandberg MXP 880 couldn’t dial into the V2IU. Could not get any combination of dial strings that we tried to work. Polycom suggested using the web interface to dial “extension@IP address” and said that Tandberg told them e.164 dialing was not supported. We couldn’t get that to work either.
  5. Dial out to Tandberg MPS. Called my Tandberg MPS bridge fine (IP address dial in).
  6. Dial in from Tandberg MPS. Figured out that to dial through the V2IU from my MPS to the Viewstation was extension@IP. (for example 123@111.222.333.444).
  7. Dial out to Polycom MGC. Called Macomb ISD’s Polycom MGC bridge fine (IP address dial in – gave the MGC the V2IU external IP address).
  8. Dial in from Polycom MGC. Figured out that to dial through the V2IU from the MGC (software rev 6.0.2.00) the extension had to be in the party extension box.

V2IU Configured with WAN Side Gatekeeper
The next tests I wanted to do required the endpoint to register to my Tandberg Gatekeeper to get ISDN access through my Tandberg Gateway and to use the Gatekeeper to get into conferences other than the first one on my MPS. To do this, we configured the V2IU with my Tandberg Gatekeeper’s IP address for the WAN side gatekeeper. The Viewstation behind the V2IU was registered to the V2IU gatekeeper. Then we did all these tests.

  1. Dial out to Polycom endpoint. Called out to my Polycom VSX 7000 (public IP). Worked great.
  2. Dial in from Polycom endpoint. My Polycom called in (using the extension box on the top right). Worked great.
  3. Dial out to Tandberg endpoint. Called a Tandberg MXP 880 (public IP) with no problem.
  4. Dial in from Tandberg endpoint. This still didn’t work. Same issue as above.
  5. Dial out to Polycom MGC. Called Macomb ISD’s Polycom MGC bridge fine (IP address dial in – gave the MGC the V2IU external IP address).
  6. Dial in from Polycom MGC. Figured out that to dial through the V2IU from the MGC (software rev 6.0.2.00) the extension had to be in the party extension box.
  7. ISDN dial out to Polycom MGC. Next we tried dialing from the Viewstation to the V2IU through the Tandberg Gatekeeper to the Tandberg Gateway to get ISDN access out to the Polycom MGC. Success!
  8. Dial out to Tandberg MPS. Called my Tandberg MPS bridge fine (IP address dial in to conference 1).
  9. Dial out to Tandberg MPS. Next we called into conference 2 by dialing it’s e.164 number. Success.
  10. Dial in from Tandberg MPS. Worked great by dialing the e.164 number of the endpoint.
  11. Dial in from Tandberg MPS. Dialing extension@IP did not work. However I suspect this is because the MPS can do this call with just the extension and was confused on how to send the call.

There are still a few unknowns, but I was very pleased with the results of these tests. Stay tuned for more learning this summer as our installation progresses.

6/29 Update. Based on some testing I’ve done today, I suspect that the Polycom Viewstations v 7.5.4 can’t call IP##Extension or Extension@IP either. The testing unit is gone, but I can see I’ll be dealing with this in the future.

0 replies on “Testing a Polycom V2IU Firewall Traversal Unit”

  1. This information was extremely useful to me, did not know to use extension@ip dialing into the V2IU from the Tandbergs until I found it here so thank you!!!

  2. TANDBERG Endpoints fully support Annex O dialing, which is the extension to H323 that allows for URI based dialing strings (ie. alias@host-address). There was an implementation issue on the V2iU platform in that it would not correctly handle the url-ID field of the incoming Q931 setup message. I am not sure if this has been completely resolved in the V2iU platform. I suggest you check the Edgewater Networks support forums, as this is where the V2iU is OEM’d from.

    A more robust and secure solution (ICSA Certified) is the TANDBERG Border Controller, which would play quite nice with your VSX deployment, and your TANDBERG infrastructure (Gatekeeper and Gateway).

    Cheers,
    Kieron

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