SIP-based VRS Providers

GraysonPeddie

GraysonPeddie

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Hi. I do have a question about whether VRS providers support SIP or not, but while I know this is a technical post that I'm about to write, I'd like to brief anyone about SIP. SIP is Session Initiated Protocol. It allows invitation (phones ringing, for example), acknowledgement (this is when session begins), terminate session (either by sending a "bye" command to complete a call or a "cancel" command if the user initiating a session cancels the call or if a receiving party rejects it), and registration with the proxy server. Please note that SIP does not handle audio/video processing. It's either the hardware or software's responsibility to provide that kind of media, whether it be softphones, video phones, analog telephone adapters, VoIP-based telephones, etc. If anyone is interested in SIP, visit the SIP tutorial. If you want to get your hands dirty in getting technical details of SIP, read RFC 3261.

With that out of the way, do any video relay service providers have support for SIP?

Here is the scenario for why I've asked: I have trixbox running in a custom-built server. Because trixbox is PBX-based, I can assign an extension number for a video phone. Pretend that I have four video phones: one in living room, one in the kitchen or dining room, one in the study room, and one in the bedroom. It's a lot of video phones, but think about that for a minute. Since the extensions I'll be giving will have a max digits of 2, the extensions for the video phones start at 20. So, extension 20 for the living room, 21 for the kitchen/dining room, 22 for the study room, and 23 for the bedroom. trixbox (yes, the spelling is intentional; it's "t" instead of "T.") has a ring group setting that can ring in all 4 extensions at once. So, a deaf VP user will dial my phone number and trixbox handles an incoming call (an "INVITE" command sent on behalf of the proxy server from a deaf caller) and because I setup a ring group, trixbox sends out 4 invitations to make the video phones start ringing (one invitation per video phone). If I'm in the dining room, I can initiate (acknowledge) a call from there. In doing so, trixbox cancels out the other video phones that were still ringing. trixbox then will send an acknowledgement back to a proxy server, which initiates the SIP session, and video communication can take place during the session.

What this means, is you don't have to have a separate 10-digit phone number per VP device that you have at home, which is very illogical and impractical to have for your home.

And yes, trixbox does have support for video-based communication.

I strongly doubt that VP200 is a SIP-based video phone, or am I wrong? Currently, I'm using CallCentric for audio-based communications (pay-per-call service), so if I plan on using VRS in the future, are there any VRS providers that are friendly to technical users who know how to setup a SIP-based video phone?
 
I think VPAD+, CDVRS, SnapOjo, MVP are all using SIP based protocol.

Not sure about Sorenson since incoming calls would not work without port 1720 so it probably still using H323 protocol.

I was able to use VPAD+ relay service from any wifi spots, coffee shop, hotel, etc but no battery pack yet.

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vp100 uses h323. vp200 uses h326. both sip on 1720 ring port.
 
Okay, so if I were to register trixbox with Viable or CSDVRS, will they see trixbox as a registered videophone once I add a SIP trunk?

Here's what it looks like:



Once it's done, I can setup an inbound route. So, when a deaf caller dials a Viable/CSDVRS number, trixbox will then route the call to its destination that I can assign, whether it be an extension number, ring group, etc. So, when I begin to add extensions for a couple of video phones (even remote extensions, too, if I decide to use a VPAD remotely from home using Wi-Fi hotspot), can VPAD communite directly with trixbox (as a reminder, it's Asterisk=based with freePBX added to it)?

(I love working with software-based PBX systems... I'm thinking that maybe in the future, I think that a video relay-based conference can work for businesses with d/Deaf employees, but who knows. Or, maybe they can hire an interpreter and start a secondary video conference for the d/Deaf, bypassing the VRS! Or, how about an SIP-based captioned teleconference as an alternative to sign language when speech recognition is used? Of course, it great for those who work from home.)
 
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GraysonPeddie said:
Okay, so if I were to register trixbox with Viable or CSDVRS, will they see trixbox as a registered videophone once I add a SIP trunk?

Here's what it looks like:



Once it's done, I can setup an inbound route. So, when a deaf caller dials a Viable/CSDVRS number, trixbox will then route the call to its destination that I can assign, whether it be an extension number, ring group, etc. So, when I begin to add extensions for a couple of video phones (even remote extensions, too, if I decide to use a VPAD remotely from home using Wi-Fi hotspot), can VPAD communite directly with trixbox (as a reminder, it's Asterisk=based with freePBX added to it)?

(I love working with software-based PBX systems... I'm thinking that maybe in the future, I think that a video relay-based conference can work for businesses with d/Deaf employees, but who knows. Or, maybe they can hire an interpreter and start a secondary video conference for the d/Deaf, bypassing the VRS! Or, how about an SIP-based captioned teleconference as an alternative to sign language when speech recognition is used? Of course, it great for those who work from home.)
Click to expand...

I know this is an old post, but did you get this working? I want to setup a similar thing but dont want to waste time if it didnt work.
 
I haven't done it myself. Unfortunately, I don't have knowledge of ASL and I've never used any VRS providers before.
 
H.323 vs SIP

The iTRS database only contains H.323 IP addresses for videophones. All deaf videophones must have an IP address in the iTRS database if they wish to receive inbound video calls.

Only VRS providers can access the iTRS database hosted by Neustar. To access it, VRS providers must be listed by the FCC/NECA as valid VRS providers, and must qualify with Neustar.

Each provider has its own "internal dialplan" for their own videophones, and must query the iTRS if their customer dials a phone number that is not theirs.

All providers must support H.323 dialing in order to facilitate customer point-to-point calls, as well as to support dial-around by phone number.

Many videophones are H.323 based only. This includes (but is not limited to) the Dlink DVC1000 i2eye (VP100), Dlink DVC2000 (VP200), Purple P3 (using their vidsoft H.323 gateway), Microsoft Netmeeting, CSD PAV public phone, some Polycom gear, etc.

If you see TCP port 1720, you're looking at the H.323 H.225 Call Setup signalling. With fast start, you won't need another H.245 port for media negotiation. Without it, you're looking at some other dynamic ephemeral TCP ports.

If you see TCP or UDP port 5060, you're looking at SIP signalling.

With port forwarding and other trickery, those well known ports aren't necessarily the only ports being used for either purpose.

Both H.323 and SIP use RTP over dynamic UDP ports for media channels.

Both H.323 and SIP negotiate virtually identical audio and video CODECs that are transmitted over those media channels.

Some videophones are H.323/SIP dual stack. This includes the ZVRS Z340, ZVRS Zojo, ZVRS Z150 (though the SIP stack isn't used at all), ZVRS Z4, SNAP Ojo, SNAP (Viable) VPAD, Purple MVP, Worldgate Ojo, most Polycom gear, most Tandberg gear, Mirial Softphone, Xmeeting, Ekiga, and there are a mess of others.

None of the VRS providers currently support what you are trying to do: registering to their federated network is supposed to only be through using equipment they provide. If you tell them you have your own PBX and are asking for your device's SIP authorization password, they'll probably tell you they can't help you.

That's not to say that you can't do it: just that you're on your own to debug and support it. You can probably socially engineer the phone's password from your VRS provider with some effort. If you're an engineer, that's probably ok. If you're a typical consumer, this is probably something you don't want to try and do yourself.

If you're a good engineer, and if you ask me nice, I can probably help you setup your home network for VRS through your own PBX.
 
(Warning: For Technical-Minded Audience Unless You Want To Read This!)

Eh, no I don't have any video phones to test on and it looks like I'll have to add the H.323 channel module for Asterisk in order for video phones with H.323 stack to communicate with other video devices through the Asterisk PBX server. Asterisk is a really nice phone system (when setup properly -- FreePBX or Trixbox is very easy to setup and get your phone system running) and it's got a lot of potential.

However, regardless of whether I have a video phone or not, the use of H.323 stack is going to make it really complicated to setup and test to make sure it works and I don't think any Asterisk users out there have made their attempts to get video pones to work with Asterisk/FreePBX/Trixbox. If they can do that, it'd be nice to have just one phone number regardless of how many videophones they have.

With SIP, IAX2, and ZapTel (do a search if you don't know what that means), FreePBX and Trixbox makes it a cinch to setup your audio-based telephone devices and softphones (like X-Lite for Windows and Twinkle for Linux). For H.323, that requires me to SSH into my Ubuntu Server, patch the H.323 channel module into the Asterisk source directory, do a make clean, ./configure, execute make menuconfig to enable the channel module, recompile Asterisk (make), and reinstall Asterisk (sudo make install).

Anyway, I appreciate for your help.

P.S.: For those who do not have expertise/knowledge of Linux, I didn't mean to lose you for being so complicated, but all I can say is compiling a program is not as easy as installing a program. But if you want to try out an Asterisk PBX system for a spin, you can try trixbox, but you'll need to burn an ISO file into your blank CD and you'll want to install trixbox in a spare computer that you don't use that often or anymore and before you install trixbox, you'll need to back up all your files or all your data will be erased.

P.P.S.: For most deaf users, you really don't need a PBX phone system, such as trixbox (that uses Asterisk) unless you have a couple of TTY devices and VoIP phone adapters lying around, such as in your closet. You'll need a VoIP adapter per TTY machine that you have in order to set this up. Although pretty much redundant, this could be very useful for communicating with other people in your house and even setup a remote extension (quite complicated, as it requires port forwarding through your router and you'll need a Dynamic DNS service such as No-IP). Or, how about video-to-video phone calls in your house/apartment? I'm sorry if I am speaking some kind of Greek language, but this is just information that I want to provide for the technical-minded.
 
Thanks for the info VRSEngineer! This is a project that i have been wanting to do for a little while now. I'm trying to tie it together with my media center PC. Any help you can provide would be great! Thanks
 
GraysonPeddie said:
(Warning: For Technical-Minded Audience Unless You Want To Read This!)

Eh, no I don't have any video phones to test on and it looks like I'll have to add the H.323 channel module for Asterisk in order for video phones with H.323 stack to communicate with other video devices through the Asterisk PBX server. Asterisk is a really nice phone system (when setup properly -- FreePBX or Trixbox is very easy to setup and get your phone system running) and it's got a lot of potential.

However, regardless of whether I have a video phone or not, the use of H.323 stack is going to make it really complicated to setup and test to make sure it works and I don't think any Asterisk users out there have made their attempts to get video pones to work with Asterisk/FreePBX/Trixbox. If they can do that, it'd be nice to have just one phone number regardless of how many videophones they have.

With SIP, IAX2, and ZapTel (do a search if you don't know what that means), FreePBX and Trixbox makes it a cinch to setup your audio-based telephone devices and softphones (like X-Lite for Windows and Twinkle for Linux). For H.323, that requires me to SSH into my Ubuntu Server, patch the H.323 channel module into the Asterisk source directory, do a make clean, ./configure, execute make menuconfig to enable the channel module, recompile Asterisk (make), and reinstall Asterisk (sudo make install).

Anyway, I appreciate for your help.

P.S.: For those who do not have expertise/knowledge of Linux, I didn't mean to lose you for being so complicated, but all I can say is compiling a program is not as easy as installing a program. But if you want to try out an Asterisk PBX system for a spin, you can try trixbox, but you'll need to burn an ISO file into your blank CD and you'll want to install trixbox in a spare computer that you don't use that often or anymore and before you install trixbox, you'll need to back up all your files or all your data will be erased.

P.P.S.: For most deaf users, you really don't need a PBX phone system, such as trixbox (that uses Asterisk) unless you have a couple of TTY devices and VoIP phone adapters lying around, such as in your closet. You'll need a VoIP adapter per TTY machine that you have in order to set this up. Although pretty much redundant, this could be very useful for communicating with other people in your house and even setup a remote extension (quite complicated, as it requires port forwarding through your router and you'll need a Dynamic DNS service such as No-IP). Or, how about video-to-video phone calls in your house/apartment? I'm sorry if I am speaking some kind of Greek language, but this is just information that I want to provide for the technical-minded.
Click to expand...

Cool.. I have plenty of spare PCs. Trixbox :hmm: I'll check that out.

Catty
 
Interesting discussion

This is a very engaging discussion. I understand from this thread and other articles that you have to be deaf or a VRS provider to be listed in the iTRS database or have access to it. How do I get a video phone number if I'm not deaf?
 
cabbs said:
This is a very engaging discussion. I understand from this thread and other articles that you have to be deaf or a VRS provider to be listed in the iTRS database or have access to it. How do I get a video phone number if I'm not deaf?
Click to expand...

You don't.
 
ummm try LINPHONE works on xp, win7 and linux like ubuntu will that help? just add the sip addy... easy.. hope I help..
 
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