Fax line only works when connected directly to cable modem.

Posts: 13 · Vonage Forum Associate Joined: Aug 14, 2007 Posts: 13

I have a Vonage fax line and a multifunction fax machine. This is a vonage fax line - not a voice line I am trying to use for faxes.

When my network is configured as follows, fax works:
Cable Modem -> Motorola ATA -> Line 2 -> Fax

When configured the way I want it, it doesn't work:
Cable Modem -> Laptop running IPCop (router software) -> Linksys Gigabit Ethernet Switch -> Motorola ATA -> Line 2 -> Fax

My vonage voice line (on line 1) works perfectly in both configurations, and I have no ports blocked that would stop Vonage from working.

I don't want the Motorola ATA in front of the router because the laptop running IPCop is a much better router. It doesn't crash under heavy traffic and has a ton of extra features. If I put the Motorola at the front of my network, it becomes the most likely point of failure for my home network.

I have already done the obvious - I have shut off ECM on the fax machine and reduced the baud rate as low as 7200 (also tried other speeds). The result is always the same. The fax machine always reports:

Communication Time: 36 seconds.
Result: NG #018, Line Busy

The line is not busy.

I have also run the speedtest in both configurations. As you can see, the network plumbing increases jitter a bit, but shouldn't slow things down enough to adversely affect VoIP.

Answers to the sticky questions:
1. Your location
Indianapolis, IN

2. Your ISP name and type (cable, DSL, wireless etc)
RoadRunner Cable

3. Upload and download speeds
Advertised 5000 up/2000 down

4. Modem make and model
Scientific American - supplied by cable co.

5. Type of Vonage adapter used ie RT31P2 or PAP2
Motorola VT1005

6. Setup of Network
Wall -> Cable Modem -> IPCop router -> Switch -> Motorola ATA -> Line 2 -> Fax

I ran the VOIP test twice. Once with the full configuration (computer connected to switch), and once with the configuration that works (computer connected directly to cable modem)
---

When computer connected to switch, and fax fails:
---------------------
Download speed: 4882312 bps
Upload speed: 1957200 bps
Quality of service: 99 %
Download test type: socket
Upload test type: socket
Maximum download pause: 39 ms
Average download pause: 2 ms
Minimum round trip time to server: 56 ms
Average round trip time to server: 83 ms

VoIP test statistics
--------------------
Jitter: you --> server: 1.9 ms
Jitter: server --> you: 4.1 ms
Packet loss: you --> server: 0.0 %
Packet loss: server --> you: 0.0 %
Packet discards: 0.0 %
Packets out of order: 0.0 %
Number of supported VoIP lines: 33
Estimated MOS score: 4.1

Computer connected directly to cable modem, and fax works:
Speed test statistics
---------------------
Download speed: 4881624 bps
Upload speed: 1960264 bps
Quality of service: 99 %
Download test type: socket
Upload test type: socket
Maximum download pause: 4 ms
Average download pause: 2 ms
Minimum round trip time to server: 56 ms
Average round trip time to server: 87 ms

VoIP test statistics
--------------------
Jitter: you --> server: 0.5 ms
Jitter: server --> you: 3.4 ms
Packet loss: you --> server: 0.0 %
Packet loss: server --> you: 0.0 %
Packet discards: 0.0 %
Packets out of order: 0.0 %
Number of supported VoIP lines: 33
Estimated MOS score: 4.1

Posts: 13 · Vonage Forum Associate Joined: Aug 14, 2007 Posts: 13

One interesting tidbit, though I don't know if it's relevant.

The fax always fails at 36 seconds, and the following happens:

- Sending fax calls outbound.
- Receiving fax picks up phone and broadcasts obnoxious fax beeping sound.
- My fax fails to transmit, stays in status "calling". When it works, status changes to "transmitting".
- Gives up after exactly 36 seconds (regardless of receiving fax machine), and reports line busy.

-->Adam

Posts: 1178 · Member of the Week Joined: Feb 28, 2005 Posts: 1178

first off, I think this post ought to be moved to the fax,tivo subforum.

second, it is definitely a problem b/w either your switch or your ipcop that is running on your laptop.

it sounds to me like the return signal from the recipient fax is not getting back to your fax machine.

definitely sounds to me like you need to tweak something in ipcop most likely.

never used ipcop so i cannot help directly but I think you have probably diagnosed it as your network causing you the problem.

the only possibility that comes to mind is that the fax return signal is taken as some kind of attack and the ipcop is killing it.

others want to chime in?

Posts: 41 · Full Forum Member Joined: May 22, 2007 Posts: 41

Agreed. Something must be adjusted in either the IP COP or the Switch. If it works straight to the modem than that means the Vonage service as a whole is working.

Nothing is changing on the Vonage end when you add more points of failure in between the Motoroal ATA and the Vonage Network. FOIP (Fax over IP) requires an even greater Quality of Service than regular VOIP. From you explanation is seems there is some service degradation for whatever reason when you add in the swtich + ipcop. If possible the best thing to do would be to use wireshark and take a trace of the call to make sure all the signaling is making it back and forth.

Like the previous poster i have experience with IPCOP so I cannot provide any suggestions as to what needs to be tweaked.

Posts: 13 · Vonage Forum Associate Joined: Aug 14, 2007 Posts: 13

Now it's getting wierd.

If I set IPCop to run with 192 MB RAM, faxes fail.
With 64MB, they work. Less RAM yields better results?

Now I'm trying to tweak traffic shaping settings to give UDP ports 10000-20000 more priority (though, I don't think bandwidth is the issue).

Now the problem is that if I only give IPCop 64MB RAM, I won't be able to use all of it's advanced features.

-->Adam

Posts: 1178 · Member of the Week Joined: Feb 28, 2005 Posts: 1178

that's good to know that it appears to be IPCop that is your configuration issue. keep at it. I'm sure there is a solution out there.