56k Restricted Sites, How to find them?

[Wolfman25]

Hey everyone, newbie to the forums and I have a good one, real quick, I work in the VC business, supporting and setting up Polycom VC systems for clients. Been doing it now for a few years, I've set up over 430 systems and I have never came across the issue below...

I have a client who is using a Polycom 7000s (a), over Isdn.
She can call out and accept calls at 336k but cannot acheive 384k calls.
We have tested with her for about a month now, we've had Verizon (local) and AT&T meet and test everything.Wires, trace the calls, they shut down locations just to push the call over different facilties, still with the same results.
The only thing they did have to change was from a CAT3 to CAT5 line coming from dmarc. Still with the same result.
We have sent her 2 complete replacement systems, including new wires, IMUX, NT even the power cords. All equal the same result.

Here the kicker, if we dial her at 128k, Calling just the 3rd circuit numbers (i'll call them 4 and 5), 4 will connect with the first spid of circuit 1.
If we call at 336, all 6 spids connect perfectly. 256k works intermittenly, 384k connects but downspeeds and drops the call.

After reading everything I can get my hands on, I'm inclined to say its either a 56k restricted site that the calls are hitting somewhere OR its not programmed correctly at the carriers. Verizons says that each circuit is configured for 64k. And they are pic coded to AT&T. They both verify that.

Question is, How do I find the 56k site if that is truly the case?

Or does anyone have any other idea of something that could be causing this?

(side note, we also tried a Polycom 512, but had the same thing happen).

Thanks in advance....

J

[robertk]

Hey everyone, newbie to the forums and I have a good one, real quick, I work in the VC business, supporting and setting up Polycom VC systems for clients. Been doing it now for a few years, I've set up over 430 systems and I have never came across the issue below...

I have a client who is using a Polycom 7000s (a), over Isdn.
She can call out and accept calls at 336k but cannot acheive 384k calls.
We have tested with her for about a month now, we've had Verizon (local) and AT&T meet and test everything.Wires, trace the calls, they shut down locations just to push the call over different facilties, still with the same results.
The only thing they did have to change was from a CAT3 to CAT5 line coming from dmarc. Still with the same result.
We have sent her 2 complete replacement systems, including new wires, IMUX, NT even the power cords. All equal the same result.

Here the kicker, if we dial her at 128k, Calling just the 3rd circuit numbers (i'll call them 4 and 5), 4 will connect with the first spid of circuit 1.
If we call at 336, all 6 spids connect perfectly. 256k works intermittenly, 384k connects but downspeeds and drops the call.

After reading everything I can get my hands on, I'm inclined to say its either a 56k restricted site that the calls are hitting somewhere OR its not programmed correctly at the carriers. Verizons says that each circuit is configured for 64k. And they are pic coded to AT&T. They both verify that.

Question is, How do I find the 56k site if that is truly the case?

Or does anyone have any other idea of something that could be causing this?

(side note, we also tried a Polycom 512, but had the same thing happen).

Thanks in advance....

J

If I understand it correctly restricted 56K channels compared to normal BRI lines differ in that way they don't have the extra 16kbit/s D-channel.

So they are still 64Kbit/s, but the signalling steal 8kbit/s from each channel leaving 56Kbit/s for data. Compared to a BRI where you have 2 B channels of 64kbit/s + one external D channel of 16Kbit/s.

I would try to ask the network providers again if you have a clear 64Kbit/s path from your customers site out to the rest of the ISDN world. And why you only get 56k / channel even though they claim to give you 64kbit/s.

//Robert

[Wolfman25]

If I understand it correctly restricted 56K channels compared to normal BRI lines differ in that way they don't have the extra 16kbit/s D-channel.

So they are still 64Kbit/s, but the signalling steal 8kbit/s from each channel leaving 56Kbit/s for data. Compared to a BRI where you have 2 B channels of 64kbit/s + one external D channel of 16Kbit/s.

I would try to ask the network providers again if you have a clear 64Kbit/s path from your customers site out to the rest of the ISDN world. And why you only get 56k / channel even though they claim to give you 64kbit/s.

//Robert

According to them (Verizon), they are 64k Clear Data. And they reiterated to me that its a 'CPE' problem. I am not against saying its the equipment but we changed it already. When asked about a 56k restricted facility, the two tech said they no nothing about that. Never heard of it. I also asked about the programming. There is a real good article about the programming at InfoComm (http://www.infocomm.org/index.cfm?objectID=E1C71807-1B95-4203-8BA55B817757F074&method=display&iPart=6)

And again the tech at Verizon had no idea, I'm currently on hold for a different tech now...

[robertk]

And again the tech at Verizon had no idea, I'm currently on hold for a different tech now...

Yea, I know... all you have to do is find a tech that know something :) Then this kind of problems gets solved smothly :)

//Robert

[Slimey]

BLAH Verizon. If you are not a large business that can make them money they dont want to have nothing to do with you.

[Gary Miyakawa]

The ONLY way to truely get this figured out is to have the complete call traced from end to end. You will need to set up and trace time for ALL carriers to be on the SAME conference call to watch the handoff from each one. There "could" be a carrier in the middle (one you might not know about) that is dropping it to a 56k call. You could also have a problem where only 1 b channel of the BRI is been configured for 56k (Yes, I HAVE had that problem before). Tell all the carriers you are having line problems and need an "End to End" trace of the call.

Good Luck !

[Joe Vallender]

What is your ticket number with Verizon...i'd like to take a look at it since I work for them and support our video conferencing service. We run into similar problems with customer sites where somewhere along the network path a segment is being taken that corrupts the data or is restricted to 56K. I can possibly do some test calls to try to identify where the issue lies.

[vbhere]

Additionally< have you tried testing each line individually i.e. disabling lines 2 and 3 and using olnu line one and see what you get. Then do the same for the others each one at a time. When testing each line you may also want to do both bonded and 2x64k calls. At least this way you can narrow down which circuit it is unless its all three !

[11B-33T]

I believe Gary hit the in the X-ring about the customer being routed somewhere in the 'cloud' across a 56k voice circuit. Reminds me of being routed over a T1 CAS trunk in the field... Hope Joe can shed some light on this one.

[Wolfman25]

Thanks for the replies and sorry for the late response, I was away all week.
When I get into the office I'll shoot over my ticket number.

[cfaasen]

I have had experience with Switched 56 circuits. I would try a unbonded call on each line (eg 1A, then 1B)locally to your CO. Then try calls outside your CO to other COs. I have had it where the lines where trunked onto 56 switched lines when it left the CO instead of 64kbps.. In one case we found out that the a carrier did not have the facilities to trunk ISDN in a certain region and was using 56 k lines.