ISDN Multiple video conference question 2

[Imstillhere]

Id like to ask the experts...

Recently i took over this site with no turnover at all.
I have 4 isdn circuits, The only thing I can tell for sure is that 3 of the 4 have been used in the past for video conferencing,they are diasy chained into 3 different conference rooms..Typically only one conference is going on at a time. the 4th one seems to go to the video conference room upstairs, but is not part of the 3 circuits already there that are needed for video conferencing.No one left here that would know,does know what it was used for so...

Question: I doubt it would come up but..Can I have 2 video conferences simultaniously in seperate rooms with the current 3 isdn line daisy chain configuration, or would I need to degrade the quality of each video conference by using only 2 lines, thus brining this unknown 4th line into play?

 

[lopes1211]

Tandberg? It's probably 1 ISDN daisy chained along. You can have up to 23 channes of video no matter what mix and match of units. Most calls are 6 channels so yes, you could have 3 units each making a 6 channel call. If 1 system was making a multi-site call (lets say 6 channles x 3), then that 1 system would use 18 of the channels and there would only be 5 channels left for the other 2 units to share/split. I think this answers your question.

-CL

 

[Imstillhere]

Yes its Tandberg, It has 3 rj45 inputs,CH1 CH2 CH3. we have seperate video equipment for each building, The Dmarc has the circuits coming in as 1 pair, The pairs are then diasy chained to a quad jack (one empty) in the different rooms labeled CH1 CH2 CH3, which connect to the tandbergs with line cords.
So i guess as far as video conferencing goes, these 3 circuits should provided adequate support for our site?? We do not use this equipment often, and it would be rare to have 2 at the same time, and even more rare that it would be more than a site to site call. I will go ahead and suspend this 4th CIRCUIT,see who complians...then have it turned off next month if no one does. Thank you again !!!

 

[donb01]

I run mine on 6 channels - that gives 384K of bandwidth and looks pretty natural.

With 3 channels you would have 192K, and it might be still quite usable but start to decay. Much less than that and the folks moving around will start to look like Max Headroom... (oops.. I probably just dated myself there... the movements would be really kinda jerky)

For netmeeting and a windows webcam you could probably do well with less - I guess it depends on the equipment they're using. That might be what they're doing upstairs with the single line.

 

[lopes1211]

ahhh, these are bri, not pri. it sounds like you only have 6 channels total, not 23. It sounds like you can only use 1 unit at a time with 3 bri's.

-CL

 

[Imstillhere]

Please dont think me ungrateful that I did not respond yesterday, Things got a litte crazy here.

Donbo,I remember Max Headroom

Do you guys think the last Admin may have kept this 4th (unused) ISDN circuit around just in case 2 video conferences somehow got scheduled at the same time, and they just used 2 circuits (4 channels) to supply each set of equipment, so they could at least function on those rare occasions?
Other than that I dont see a reason to pay for this circuit every month. I have traced this circuit from Dmarc to jack, it only goes one place, and there is nothing there

Anyway, I would certainly appreciate any insight you might have as to why I should or should not keep this circuit around.

Thank you for your time.

 

[jerryreeve]

when we used bri's for confrence the confrence could fire up on 1, 2, or 3 bri's working, it just started to degrade with the loss of a couple of channels but the basics were still there.

----------------------------
Hill?? What hill??
I didn't see any $%@#(*$ Hill!!
----------------------------
JerryReeve
Communication Systems Int'l
com-sys.com

 

[GHTROUT]

The system might be capable to using 4 circuits, such as for bridging multi-point calls together from your site (rather than subscribing to a bridge).

3 circuits is fine for simple point to point calls.

If you participate in multi-point calls, I'd use a bridging service (which negates the need for the 4th line). If you just call one other site, then the 4th ISDN line is probably uneeded in all cases.

You might as well not have video if only one circuit is available (say if two calls were scheduled at the same time). It would be too distracting to deal with the delay.

I did the same thing as you're finding. Three circuits daisy chained between the the two board rooms, but a 4th circuit in the large board room for multi-point call setup...which we found was poor quality if we tried to be the bridging point.

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[Imstillhere]

I just found a Piece of Video Conf equipment hidden away, called a Picture-tel.. what a mess of cables in this thing yikes!!, I fired it up but I cant get past the login screen… (It's PC driven)It also explains this unknown 4th ISDN line.
Tucked away in the back of the unit behind a plethera of cabling was 4 line ISDN modem…..So now its off to Google to see what I can find out about this ‘ol gal. (camera is APTZ-1N. Modem is ALPHA TELECOM QUAD NT1,4port ISDN card in the pc's WAN slot)If anyone knows anything about it I would appreciate some input, there is no documentation on the cart..it appears to have been hidden away for quite some time, but It seems to working.. I just cant get in it...maybe I should just put it back in the closet and pretend I never saw it, I'm thinking maybe someone else started this endeavor once before and was never heard from again

 

[GHTROUT]

I would leave that one hidden away. For any changes or improvements, I'd look at a PRI or broadband based connection and abandoned the BRI, which might not even be available in a year.

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[Imstillhere]

GHTROUT You have never steered me wrong in the past, so I will put "Christine" back in the closet, with a note to leave her in there.
I will start looking at the alternatives you suggest, I doubt i get approval to spend the money, but it should be a good learning expierence.

Thank you all !!