Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

ISDN-> 3540 Gw2p not working

I have been beating my head to a bloody pulp trying to get this to work. Hopefully someone here has an answer.

I have a 3540 Gw2P I am trying to setup (SW 5.0.22). I can make Ip->ISDN 384Kbs calls all day long. However I cannot connect ISDN->IP at greater then 128K (128K and 64K calls work like a champ).

On my ISDN VC system (Polycom VS4000 SW 6.0.5) I get a cause code 28 "Invalid number format" error whenever I try a 384Kbps call. On the GW event log I see "ISDN Downspeeding" and then "Abnormal Disconnect" for these calls.

Part of my frustration is I cannot find out how to do ISDN tracing on the 3540 GW2P.

Does anyone have any ideas??????


Nathan Spitzer

Sr. Network Communication Analyst

Lockheed Martin - TSS Rockville

  • Video Over IP

Re: ISDN-> 3540 Gw2p not working

If you had access to ISDN tracing, I would highly recommend you to look at the Bearer capability field ;)

New Member

Re: ISDN-> 3540 Gw2p not working

It just so happens I got a trace this morning from the ISDN Polycom. Here is a snippet:

BOND received phone number for channel 4, bondTicker = 13116959

extractNum[0]: extracted chan 4 number = 7007483647

BOND: Xmt IC msg - 134 13116960 - 7f 81 83 9f 8d fd 81 8d 8b ff ff ff ff ff ff ff


BOND: 0 1 1 6 7 64 0 0 0 0 0 6 5 PPPPPPP

Now the truly interesting thing is I got no idea where it pulled 7007483647 out of as a number (BTW, I see the same thing for all the other channels). Our ISDN numbers begin with 700301 and nobody knows nothin' 'bout 7007483647. It so happens if you try to call that number you get an error along the lines of "No networking equipment has that number"

I got a call into Sprint so maybe something will come of that.

Is there any way to do a trace from the Gateway??? If there is I cannot figure it out.

New Member

Re: ISDN-> 3540 Gw2p not working

After doing a trace and getting Sprint on the line, Sprint says that when the other B channels are trying to bond, the GW is sending back 7007483647 as the number to dial. That number is nowhere that I can find in the config of the Gateway or gatekeeper. Does anyone have any idea what this might be?????

New Member

Re: ISDN-> 3540 Gw2p not working

Well, I have conclusively provin that it is the gateway because I plugged a known good Polycom VC into the PRI and it came up like a champ.

I then rest the GW to factory defaults and reconfigured it, same thing.

If anyone knows how to do an ISDN trace on a 3540-Gw2P please let me know.


This widget could not be displayed.