Fax settings for incoming faxes on PRI??

[DP]

Anyone have suggestions to improve inbound faxing over PRI? I have our main fax number being sent to Switchvox 5.5.3 and we get many complaints that faxes just won't go through. The logs show short duration calls over and over as the sender keeps trying.

Currently the channel group is set to Full Buffers with 20 buffers set. Any other ideas?

Thank you!!

[lorsungcu]

Is it a real PRI, or telco > SIP > gateway > PRI > switchvox?

[DP]

It's a real PRI. I do not have any SIP connections to the telco.

Thanks!

[brucexx]

I think what lorsungcu meant is if you have PRI connected from a "smarjack" which would be the "real" PRI or from a telco router for example Adtran or Cisco router. In many cases you might have a PRI but the truth is that the 24 channels comes to you over SIP and only the hand-off to your equipment is PRI.

[DP]

This is a real PRI from me to the telco. NI2 signalling, Qwest type 2 circuit to Integra Telecom.

[lorsungcu]

Alright. It sounds a lot like this is a SIP circuit that they are handing off as PRI, but if it isn't, then that rules something out, anyway.
So I understand correctly, you are trying to send faxes to a DID on the Switchvox, which terminates to a fax machine? Is the fax machine on an ATA or a TDM card on the Switchvox?

[leemason]

Which codec are you using for the SIP connection? Always stick with G.711 as other codecs can mangle the FAX traffic.

[david55]

Lee, I don't think it has been established that there is any SIP involvement here at all.

[leemason]

If the PRI is into a SwitchVOX system it stands a good chance that SIP is involved somewhere unless of course the FAX is into an FXS port on a separate analogue card. But I guess it could be.

[DP]

Again to be clear, there is NO SIP INVOLVED! This has been confirmed several times with the CLEC. This PRI goes directly to a DMS-250 switch. (Analog for the win!)

The PRI terminates on the 355 and the faxes go to a virtual extension on the 355. My thought is that I need to tweak the fax buffer type and quantity.

Thanks for any help!

[jonbayless]

And the virtual extension goes where?

Or are you saying that the switchvox system has the fax license and accepts the fax and stores it as a PDF or whatever?

To clarify, the DMS-250 is a switch at the telco central office, not in your building right? It is essentially the 'other end' of the PRI from you. On your end, it plugs into a card in the Switchvox 355 appliance?

I haven't used any line cards on my switchvox systems, just SIP trunks. I set fax settings on the SIP providers to disable t38 reinvites and to a minimum speed of 2400 baud and a max of 14400. That is the only way I have seen fax be reliable over VOIP.

[DP]

The virtual extension is on the 355. Once a fax is received, it is PDF'd and sent to the assigned recipient. I have a number of fax licenses on the 355 that handle faxes currently.

The DMS-250 is on the CLEC side, connecting to my 355 via PRI card.

I am interested in your SIP faxing experience - Someday I will migrate to SIP for cost savings and was curious how it was going for you. Do you see many failures with your current settings?

Thanks!

[jonbayless]

I haven't made heavy use of it. I did some basic testing and it worked ok. We use a fax service right now for inbound faxes and hardly do any outbound anymore.

We are using Linksys/Cisco PAP boxes for the one remaining fax machine in use and it hardly ever gets used and for security/fire alarm systems. They hardly ever do anything either but they seem fine.

Or last system was a Cisco call manager system with Cisco ATA boxes for the fax machines and they were pretty terrible as well until we manually configured the fax machines to disable the faster connection rates. Then things got pretty reliable.

[DP]

I would like to reduce the fax transmission rates as well, but there are no settings that I can see that would reflect this. The only settings I see are for the buffers in the channel group. The admin guide is useless as well as support. I'm escalating with my distributor (again) to see if I can get an answer to the issue.

Thanks.

[hh2011]

Weird.

I have an Integra PRI. I just moved it to the newer PRI (Thats really SIP to my ADTRAN, then PRI SIGNALLING to the SWITCHVOX)

I had no issues at all with inbound faxes at all with either circuit.


Is this complaint coming from multiple people? Or is it coming from an office where multiple users would be sending you faxes via the same machine?

I have noticed a handful of machines that can not fax to us over the PRI, but it has been a very very small amount of complaints. Users here get 100s of faxes in a month over the PRI.

I have my number of buffers set to 12 and the buffer policy to half.

[DP]

I have a lot of faxes coming through just fine, the issue that occurs is that, like you, I have a handful of senders that consistently fail. In speaking with some of them, they are sending from their PC's or fax servers. My guess is that the digital->digital connection (PC-->Digium) is too much for the fax. I can't have some of our senders just not work. I would be forced to go back to the analog fax (Sharp Copier Multi-Function) and add 1FB's.

My current settings are, buffers: immediate, 32. (Again, since support hasn't responded with any intelligent response, nor asked to look at the logs, I'm at a loss)

Thanks.

Weird.

I have an Integra PRI. I just moved it to the newer PRI (Thats really SIP to my ADTRAN, then PRI SIGNALLING to the SWITCHVOX)

I had no issues at all with inbound faxes at all with either circuit.


Is this complaint coming from multiple people? Or is it coming from an office where multiple users would be sending you faxes via the same machine?

I have noticed a handful of machines that can not fax to us over the PRI, but it has been a very very small amount of complaints. Users here get 100s of faxes in a month over the PRI.

I have my number of buffers set to 12 and the buffer policy to half.