Fax issues.

Posts: 4 · New Forum Member Joined: Apr 19, 2004 Posts: 4

I changed my bandwith to 50 from 90 today and everything is back to normal and working great. We will see how long this lasts.

Posts: 104 · Vonage Forum Senior Joined: Jan 31, 2004 Posts: 104

Faxing over an IP connection is well known and relatively well understood. It's known as FAX RELAY mode. A bit of the rub here is that the Cisco ATA 186 does not support FAX relay, instead when it hears a fax signal, it should automaticallly switch to the high bandwidth G711 codec and simply pass-thru the signal.

More information ...

http://www.cisco.com/warp/public/788/ata-fax.html

The problem of this two fold, 1 - pass thru is done on a best effort basis, meaning if the two fax machines are particularly sensitive -- then communication could be corrupted or worst the connection lost. 2 - fax machines have a long issue of compatibility problems (go figure) each one have some particularly nuance in how they expect transmissions. The test gear market offers fax testing equpment that emulates 100's of various manufacturers -- for the most part compatibility has been achieved -- however the pass-thru mode can and does create problems. Meaning sometimes it works -- sometimes it doesn't.

It's unclear whether the Motorola devices simply supports pass-thru or true FAX RELAY mode (documentation unclear) -- my guess is that it's probably only

Summary
Faxing via IP has always been a bit hit or miss and clearly this hasn't changed. Lowering your transmission speed, fiddling with other settings will increase reliability but 100% perfection probably isn't likely.

Posts: 22 · Vonage Forum Associate Joined: Mar 14, 2004 Posts: 22

Well, a week or so later and I still cannot fax via either the brother or the HP I have here. Vonage customer service is useless and just keeps repeating "drop fax speed to 9600, install dsl filter, bla bla".
I've told them if this is not resolved by tomorrow I'm going back to POTS lines, this is so embarrassing. I've been sending a partial (1 of 4 pages) fax to a supplier daily for over a week now, not the best way to win more business for Vonage.

The only thing I can think of that might be an issue is that my Motorola is behind my router and modem. Voice works fine though and I can initiate a voice call on the fax line just fine, so I doubt that's it.

Any final suggestions before I punt?

Posts: 22 · Vonage Forum Associate Joined: Mar 14, 2004 Posts: 22

I called Vonage again. Got a nice guy who suggested he could make some changes that might help, if I had the bandwidth. We ran some tests and he said b/w was fine, so he made the changes. I tried faxing to him and was successful, but not to the number I've been trying all week. I figured it was probably an issue at the remote end so I thanked him.

I then tried faxing to 2 other numbers, both failed. I plugged the same fax machine into my home POTS line, and was able to immediately send to all 3 numbers I tried, including the original one that was an issue.

I can only conclude that faxing via Vonage is seriously broken, or at least my setup is, and if Verizon offers me anything close to Vonage pricing, I'm going back. I'm all for being an early adopter - if it works.

Posts: 22 · Vonage Forum Associate Joined: Mar 14, 2004 Posts: 22

Called tech support again tonight, they again made changes and had me reboot the adapter. Faxes again failed. AAARGH.

Posts: 50 · Full Forum Member Joined: Mar 10, 2004 Posts: 50

The only problem I have ever had was a line error in the middle of a long fax and the sending unit called me back and resumed where it left off.

Posts: 22 · Vonage Forum Associate Joined: Mar 14, 2004 Posts: 22

They keep telling me to drop the line speed to 9600, but neither fax machine can do that. I will try a DSL filter on the line tonight and that's my last attempt.

Posts: 38 · Posted: Tue Apr 27, 2004 11:37 am Post subject:

sYstEm wrote:

I got a funny feeling this whole Voip think ain't quite ready for prime time.

Close, but no cigar.

Not trying to be rude, but this isn't DATAoIP.

Posts: 50 · Full Forum Member Joined: Mar 10, 2004 Posts: 50

I don't think a filter will work with Voip. Most faxes have an auto fall back, where they negoaite the line speed, much like a modem does. I have faxed to many machines and received from many machines and have only a few errors, and thoes were auto corrected.

Posts: 104 · Vonage Forum Senior Joined: Jan 31, 2004 Posts: 104

It is truly interesting to watch the many posting concerning "how to send a fax via a Voip provider". More interesting is that Voip providers have "sold" the service often for it's fax capabilities.

The reality is faxing via the G.711 codec will not work 100% of the time. If you're uplink (which has to be a constant 90 kbps) glitches -- your fax machine or the receiving end can get upset and simply fail.