Unable to get VOIP Faxing through firewall

sseverin · 01-27-2012, 03:23 PM

We are using a VOIP supplier for faxing, all of our VOIP calls work correctly, but when trying to setup the fax service, the fax extension is not responding to the call.

I have a screenshot of the wireshark exchange attached. I have allowed the port 10000 out from our server and I see it gets allowed through the firewall, so I am at a loss as to what is going on.

donhwyo · 01-27-2012, 03:37 PM

Faxing over voip is a nightmare at best. If the faxes are important get a pots line or a service that does it for you. Receiving is less trouble than sending but both are trouble unless you have qos from your isp and paying big buck for it. That would cost more than the pots line.

Don

sky-knight · 01-27-2012, 03:50 PM

I was able to get my merchant terminal and a fax machine to work on a magic jack just by plugging it in.

That said, VoIP + NAT for ANYTHING is a royal pain.

The first thing I can suggest is config -> networking -> advanced -> general.

Make sure the SIP NAT Helper is disabled. If you have to turn it off, remember that changing that setting requires a reboot of Untangle to sink in.

Once Untangle isn't automagically adjusting SIP packets, you're back to packet/port troubleshooting.

I wish you luck, you're going to need it.

sseverin · 01-27-2012, 03:50 PM

We are using this same line for our VOIP lines for our company, so the QOS is not an issue. We just need to get this working through our firewall, just the receiving, not planning on faxing out.

sseverin · 01-27-2012, 03:59 PM

Also this is going to a virtual fax machine that will automatically email the document to my manager, so a POTS line won't work for this.

sky-knight · 01-27-2012, 04:11 PM

Reception of the fax must still be a PSTN event. Someone dials a phone number, and a fax machine answers. All you're doing is putting the PSTN portion of this process across the Internet at a VoIP provider and complexifying your environment.

The process of receiving the fax, and turning it into an e-mail is also equally normal. You still have to receive the fax, and there are many things that will take the tiff received, and either e-mail it directly, or convert it to PDF and e-mail it.

So a POTS line is required, if you're using it or not is irrelevant. (Ok fine, in this case it could not be a POTS line but a PRI trunc, but still.)

donhwyo · 01-27-2012, 05:50 PM

What are you using for your connection, an ata of some sort? Try an analog phone in the line. If your phones work fine there is not a problem with your setup. Fax is very time sensitive and it requires everything to be almost perfect. If packets are drooped or late it will retransmit but after too many errors the sender will drop the call. There are some qos setting within untangle. You could try those.

You need to give a few details because my crystal ball is fading fast due to all the sun spot activity.

Don

01-27-2012, 03:50 PM	#3 (permalink)
sky-knight Join Date: Apr 2008 Location: Phoenix, AZ URLs submitted: 8 Posts: 15,454	I was able to get my merchant terminal and a fax machine to work on a magic jack just by plugging it in. That said, VoIP + NAT for ANYTHING is a royal pain. The first thing I can suggest is config -> networking -> advanced -> general. Make sure the SIP NAT Helper is disabled. If you have to turn it off, remember that changing that setting requires a reboot of Untangle to sink in. Once Untangle isn't automagically adjusting SIP packets, you're back to packet/port troubleshooting. I wish you luck, you're going to need it. __________________ Rob Sandling, BS:SWE, MCP Intouch Technology Phone: 480-272-9889 rob@intouchtechllc.com UntangleAppliances.com Phone: 866-794-8879

01-27-2012, 04:11 PM	#6 (permalink)
sky-knight Join Date: Apr 2008 Location: Phoenix, AZ URLs submitted: 8 Posts: 15,454	Reception of the fax must still be a PSTN event. Someone dials a phone number, and a fax machine answers. All you're doing is putting the PSTN portion of this process across the Internet at a VoIP provider and complexifying your environment. The process of receiving the fax, and turning it into an e-mail is also equally normal. You still have to receive the fax, and there are many things that will take the tiff received, and either e-mail it directly, or convert it to PDF and e-mail it. So a POTS line is required, if you're using it or not is irrelevant. (Ok fine, in this case it could not be a POTS line but a PRI trunc, but still.) __________________ Rob Sandling, BS:SWE, MCP Intouch Technology Phone: 480-272-9889 rob@intouchtechllc.com UntangleAppliances.com Phone: 866-794-8879

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01-27-2012, 03:37 PM	#2 (permalink)
donhwyo Master Untangler Join Date: May 2008 Posts: 296	Faxing over voip is a nightmare at best. If the faxes are important get a pots line or a service that does it for you. Receiving is less trouble than sending but both are trouble unless you have qos from your isp and paying big buck for it. That would cost more than the pots line. Don

01-27-2012, 03:50 PM	#4 (permalink)
sseverin Newbie Join Date: May 2011 Posts: 12	We are using this same line for our VOIP lines for our company, so the QOS is not an issue. We just need to get this working through our firewall, just the receiving, not planning on faxing out.

01-27-2012, 03:59 PM	#5 (permalink)
sseverin Newbie Join Date: May 2011 Posts: 12	Also this is going to a virtual fax machine that will automatically email the document to my manager, so a POTS line won't work for this.

01-27-2012, 05:50 PM	#7 (permalink)
donhwyo Master Untangler Join Date: May 2008 Posts: 296	What are you using for your connection, an ata of some sort? Try an analog phone in the line. If your phones work fine there is not a problem with your setup. Fax is very time sensitive and it requires everything to be almost perfect. If packets are drooped or late it will retransmit but after too many errors the sender will drop the call. There are some qos setting within untangle. You could try those. You need to give a few details because my crystal ball is fading fast due to all the sun spot activity. Don