Bonding Issue

[Mozinaw]

I've got a Polycom NT4620 NT1 interface going into a picture-tel system and I am not able to bond the lines. Currently I am only able to connect at 128 kbs but I'm not able to connect at any higher rate. I'm using service from a MLS100 telephone switch and it is programmed for National 1 service. The NT1 has a group of dip switches on the bottom of the unit but I'm not sure if they are set correctly. I think this has got to be a hardware issue but I have no experiance with this equipment. Can anyone help?

[Joe Vallender]

What model PictureTel codec are you using and what are you using for the bonding (Ascend IMUX?)? What is the interface from the NT4620 to the codec? Are you receiving the calls or initiating the calls?

[Gary Miyakawa]

The question I have is, Did you connect at 128kb (by dialing 1 number) or did you actually connect at 2x64kb ? If you connected at 128kb (actually, a bonded 128kb call on 1 BRI) then the bonding is working on the first line, but something is wrong with the other lines (DDN, SPIDs, configuration, area code, etc)... If you DID dial at 2x64kb (typically, dialing 2 numbers and/or specifying it's a 2x64 call) then you may have a hardware problem on the Imux. (with those hardware questions from above that need to be answered)...

Good luck !

Gary Miyakawa

P.S. Did this ever work ?

[Mozinaw]

The NT interface does accept 4 ISDN lines. We are only using 3 to try and get a total of 384 kbs. Right now we can only send or receive at 128 kbs. So the 3 lines that the Telco provides go into the U interface side of the NT box and then come out the ST side and go into the Polycom 970 system. All the ISDN lines have been checked through a loopback and all are 64 kbs with no restriction. I appreciate your help!

[Mozinaw]

We are using a Polycom 970. I assumed that NT4620 provided the bonding but I guess I am wrong in that assumption based on your comment. Is there another piece of equipment that needs to go between the NT box and the interface on the back of the Polycom system? The interface on the back of our Polycom accepts 4 (we are using 3) ISDN lines.

[Gary Miyakawa]

The iPower 970 can come with either a Quad BRI card (which, you obviously have) or a V.35 card. The QBRI Card has 4 BRI connectors (that require S/T format ISDN) should connect directly to the 4 ports of the NT1 (or 3 in your case). You should get green lights on the NT1 (no flashing or reds). If anything is flashing or red, then you like have a Telco issue.

Where did the SPIDs come from ? Telco ? You could try letting the system auto find the SPIDs. You do this from the Admin Tool and make sure you clear out ALL the old information (and press the apply button) before you try to let it find your lines again.

Once it finds the lines (or your rekey the SPID information) be sure and reboot the system. Only at boot up does the 970 look at the configured line information.

You could try swapping line 2 for line 1 and move the SPID information to see if it works, if line 1 then works, it's likely you have a bad NT1 (and only line 1 in the NT1 is working).

Good Luck!

Gary Miyakawa

[Mozinaw]

Well, we've made some progress but we are still having some bonding issues. The telco removed the 01 from the end of the SPIDs and that seemed to help a bit. We removed the 01 from the Polycom software as well and now we are able to make calls at 256 using a loop-back site. The odd thing is that the first two SPIDs bond no problem but then the second and third set don't want to bond. The person at the telco also changed a protocol setting from bell core to NI1 and those two changes have got us to where we are but not totally bonded. Does anyone have a good test site that can be used to test 384? I've got a whole list of numbers and none of them seem to work including the ones from the Ploycom Web site. The lack of good test sites is half our frustration!

[Mozinaw]

Thanks. The lights are all solid green so that is a good indication. SPIDS are from a Telco. NORTEL MSL100. I noticed that auto find parameter but we haven't tried that yet. We will give it a go.

[Gary Miyakawa]

"most" sites in North America seem to be using "NI1" (National ISDN 1) protocol. Also, typically, the SPID format is (aaa)-nnn-nnnn-0101. The aaa is the area code, nnn-nnnn is the 7 digit ISDN number and 0101 is the Identifier though, it can change depending on the Telco's configuration.


If NI1 still seems to have trouble, you might try DMS100 and see if that makes it any better.

What part of the country are you in ?

As for test number, check on the Polycom Website. There are a number of test sites listed there.

One quick question, do all the numbers have the same area code ? For bonding to work correctly, both ways, all numbers MUST have the same area code (and they "should" have the same exchange if possible for best performance)..

Gary Miyakawa

[Joe Vallender]

From my experience with sites failing to bond completely, the issue usually is in the order the lines are physically plugged into the codec mismatching the order they are programmed in the codec software. This is assuming the lines are fully operational with matching SPID's programmed in the codec software that matches what the TELCO has programmed.

I have test numbers that can be called for troubleshooting.