VRI (Video Relay Interpreting) using DSL

[Ken Moon]

We are developing a solution for a hearing impaired organization using H.323. While we have successfully performed these sensitive signing sessions over a dedicated "T", we need to deploy many of these endpoints to locations using cable or DSL connections. As some of the teaching sites only have ISDN (384 kbs) we will use a gateway for the 320/323 conversion. We are aware that we can order "business-class" DSL with a "guaranteed" 768kbs up/3meg down pipe, however, we have not actually used it.

My question: has anyone used a "RoadRunner" type service to successfully sustain a 30 fps conference call?

[tom9933]

Ken,
I’ve done quite a bit of testing with Road Runner and here is what I’ve found. Basic home service is rated at 3Mb down and 384k up so you can normally sustain H.323 calls at 1920k down and 256k up. With the next bump up you get 3Mb down and 512k up. In my case this is called a telecommuter package and with it I’m able to sustain calls at 384k up and 1920k down. Now the next part of the equation is the path from the cable modem provider back to the head end. In our case this was initially about 20 hops and we had seen some problems at one of the hops. The good news is that this hop now seems to be ok and we also came up with a workaround solution.
The work-around was to put commercial class Road Runner connection at the head end. In our case we discussed hooking up a 10Mb to a second IP card on the MGC. We looked into this scenario when we talked about adding several off site conferencing locations (home offices) but the project was never funded so we never installed the additional connectivity. I still have a VSX7000 at my house that your could call into if you’d like to do some testing. If you want to try this just contact me directly.
On a related note several years ago we also used our video conferencing systems to support hearing impaired students. The system worked by using a distance learning classroom and sending the audio and video to a stenographer who received the call at her house with net meeting. As she heard the conversation in the classroom she sent back the text by sharing the application that talked to her stenographer’s machine. We then put a monitor in front of the hearing impaired student to show the shared program. When we initially did the project there was a lot of talk about a very large deployment, but when funding was cut the project died. It’s a shame that this project didn’t go farther because it was a great use of the technology.