This post has been simmering in my brain for a while, especially after another season of Read Around the Planet and all the dialing challenges that come with it. I know that my technical knowledge is not complete, and this may not be accurate within a few months or years. Still, I think it needs to be said. I invite anyone who would like to correct me to please use the comment feature to add your knowledge and opinions, especially the vendors.
The Problem of Dialing
So here goes. As the vendors try to find ways around the limitations of IP address dialing, firewalls, etc., they are creating a nightmare of dialing problems for those of us who use VC to connect 95% of the time “off net”, off our network, and with schools around the world. Here’s my view of the current situation.
Polycom IP##Extension Format
Polycom’s firewall traversal unit means that outsiders dial the IP of the unit and then ## with the alias of the endpoint behind the firewall. This allows for one public IP to be shared with other units. This is true for the V2IU, and I don’t know about the new Video Border Proxy. In addition, the RMX uses this format for it’s meeting rooms, and the MGC can be set up this way for meeting rooms as well.
However, here’s where it doesn’t work:
- Tandberg endpoints can’t dial this format
- Tandberg MCUs can’t dial this format
- Anything registered to a gatekeeper can’t dial this format because gatekeepers strip off the ##extension.
Currently on the RMX, if someone can’t dial the IP## Extension, and you can’t dial out to them, there’s no way to get them into the conference.
TANDBERG Extension@IP Format
TANDBERG endpoints behind a border controller are dialed using the extension@IP format.
Here’s where this doesn’t work:
- Polycom endpoints can’t call that format
- It’s intermittent with at least my TANDBERG MCU. It worked before Read Around the Planet but then since then I can’t call 3 different places in 3 different states that use this format. Haven’t had time to open a ticket yet, but it’s annoying that nothing changed that I know of and it just quit working.
TANDBERG Codian Far End Camera Control
On the MCU side, the Codian MCU, recently bought out by TANDBERG, most often uses an entry room where the enduser uses far end camera control or tone dialing to enter the correct conference. It remains to be seen how TANDBERG will adapt the Codian technology. The far end camera control method works on most endpoints, except:
- Getting far end camera control to work through another MCU is problematic at best. The tones or far end camera control usually aren’t passed from one MCU to the other.
- Some legacy endpoints such as VTel (yes those are still out there in schools)
Now I can just hear in my head all you techies telling me, why are you doing endpoint to MCU to MCU to endpoint dialing? Why are you dialing off net? Why don’t you just dial out to these problematic sites? Why doesn’t everyone just get rid of those “legacy” units? Well, here’s what’s happening in schools.
- Dial out only. Fairly often, techs are nervous about NATing a static IP for H323 videoconferencing, so they only allow dialing out. If you can only dial out and you can’t dial the other site’s weird dialing, then what?
- Dial out only through MCU. Many educational service agencies have a WAN where their schools can only connect out through the MCU. Hook two schools together this way, and you have to do endpoint to MCU to MCU to endpoint. A large number of my calls are like this. Sometimes not even by technical necessity, but because it’s easier to support the local schools by scheduling calls for them.
- Dialing Predominantly Offnet. I wish I could just drill it into engineer’s heads that if a school or district is getting videoconferencing for enrichment/content providers/collaborative projects etc, they will do almost ALL their calls off net. But the vendors seem to be thinking mostly about internal corporate communications on a corporate network. All the while they enjoy and promote big events such as Read Around the Planet and Kids Creating Community Content which require offnet dialing to outside schools.
- Legacy Lasts a Long Time. We also tend to get VC equipment and expect it to last 10 years. VC is still most often purchased with grant funds (not sustainable) and schools can’t drop $6-10K every 3 years or so to upgrade their VC equipment. It’s just not happening!
Some sales guys have told me that dialing should only happen through gatekeepers. I realize that the higher ed / Internet2 / Megaconference community has the Global Dialing Scheme (GDS) which sometimes helps. However:
- Schools not familiar with GDS don’t want to neighbor to each other’s gatekeepers. Imagine in the two weeks of RAP, the huge participating schools with 120 connections. That’s 120 different sites to call in two weeks. Should we neighbor to every single other site we connect to. It’s insane to expect this.
- Many small schools just get an endpoint only. They don’t have an educational service agency or statewide network to connect to a gatekeeper and get on GDS. How will they dial?
It’s not realistic to expect that the K12 VC community would be able to do dialing through gatekeepers only. The necessary structure isn’t in place, and probably won’t be anytime soon.
Dear VC Vendors: Please Fix Dialing
So, this is my plea to the vendors. Please think of us in the K12 community where we make most of our calls off our network. Surely corporate customers need to call off their network too. When will H323 videoconferencing work like a phone (platform independent, just works)?
I don’t know what the answer is. But dear vendors, would please get over your proprietariness and make the dialing work between all H323 endpoints? Please!