Wired Intelligent Edge

I have just upgraded my very first NBX install (NBX 100 running 4.1 Code) from 2001 to a brand new V3001 Analog.

Dialplan imported fine, recreated the users manually, and everything purred along well, until the client complained that their faxes seemed to be taking longer to send.

For some reason the fax now only connects at 2400bps, whereas before it connected at 9,600 or 14,400 bps.

I even plugged in the original ATA into the system, and after it was discovered plugged the fax back into that (rather than the two inbuilt FXS ports) and the same issue persists.

A fax Test to a diagnostic number rates the call quality as excellent, but that it can only negotiate 2400bps now.

Anyone else had this happen ?

-Michael

What version of NBX code did you upgrade to ?  You must upgrade form R4.1 to R4.2 to R4.3 to R5.0 to R6.0

Also ,

In the ATA settings , is it set up as a fax machine ?

Was not upgraded. NBX 100 was replaced with a V3001 Analog. It came with R6 software.

Yes it ismarked as a Fax Machine.

Alright have investigated this further, and it appears to be an issue with the ISDN ports. We have three different services coming into the 4 ISDN ports, all seem to show a unidirectional static/hiss/scratchiness completely uncharateristic of the NBX or digital services.

But inbound audio is flawless as I have come to expect.

Just outbound audio has this poor quality.

This would explain why outbound faxes negotiate slowly, and inbound faxes train better.

But what would cause unidirectional poor quality on ISDN ports on an NBX system ?

Good Question as I do not know . I will ask around and try to get you an answer .....

Really interesting issue .

Can you try to make a call out of the first line in the group and see how the audio quality is ? Myabe a dsp or something else acting up .  I asked for a second opinion on this as well  because the faxes control the speed and not the ATA's .

Interesting issue . Also make a fax call on a lower channel as well . I would need a trace to see some of the negotiating here but my best guess is that something on the Fax machines .

Did you run the same test on the older NBX ?  Curious to see if the test results are the same on both NBX'es .