Intermittent non-connecting calls and loss of dial tone

Posts: 6 · New Forum Member Joined: Nov 26, 2008 Posts: 6

Hi everybody,

I'm having a problem which is hard to diagnose because it doesn't happen all the time. When it works, my Vonage service is good.

A few times each day, incoming calls cannot be answered. I pick up the phone and shout "Hello?" into a dead line. From the times I've been calling home, I know that the other side hears the ringing, then it goes to voice mail.

Probably related to this, sometimes when I pick up the phone to make an outgoing call, no dial tone is heard. Nor is there a friendly voice from Vonage telling me of any connection problem.

Both of these problems usually go away quickly. For instance, if somebody calls and the call can't be connected, we can usually call them right back (as soon as the caller gives up trying to call, or leaves their message).

One one hand, the problem is intermittent and there is a workaround. On the other hand, it's annoying and sometimes causes us to use our cell phones instead, thus paying cell minutes for Vonage's problems. So it's something I'd like to fix.

Here is my setup and speed test numbers from a recent test. Mind you, this is when it was working. I tried last time it wouldn't connect to get a test of the line when it wasn't working, but the line was already back.

Roselle Park, NJ (Northern NJ--908 area code)
Comcast internet service
upload/download speeds below
Cable Modem: RCA DCM425
Router: NetGear RangeMax WNR834B v2
Vonage adapter: Linksys RTP300

Configuration:
Comcast->Cable modem->NetGear router->Vonage
PC connected to NetGear through ethernet
Mac and iPhone connected to NetGear wirelessly

Our principal phone is a Panasonic KX-TG5622 5.8GHz multi-receiver cordless. We also have a wired phone connected .

Speed test statistics
---------------------
Download speed: 4539208 bps
Upload speed: 6372768 bps
Quality of service: 98 %
Download test type: socket
Upload test type: socket
Maximum download pause: 64 ms
Average download pause: 7 ms
Minimum round trip time to server: 55 ms
Average round trip time to server: 57 ms

VoIP test statistics
--------------------
Jitter: you --> server: 0.6 ms
Jitter: server --> you: 3.6 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: 77
Estimated MOS score: 4.2

Looks good to me. Any clues from the experts?

Posts: 261 · Posted: Fri Nov 28, 2008 6:00 pm Post subject:

This does not sounds like an IP issue. This sounds like an analog issue of the Off Hook signal not being detected by the RTP300 when your phone is picked up. This would explain why you don't hear the IVR message when you do not hear a dial tone due to you still have SIP registration and device does not know your phone is picked up. This is also why you hear phone ring on an inbound call but when you pick up, no Off Hook signal is detected therefore the RTP300 does not send back a 200 OK alerting the proxy that you have answered your phone and to start an audio session. This would cause caller just to go to VM or whatever your default calling feature is set to at that time.

What makes me this think this is what the root cause is because you mention you have a cordless and wired phone connected to 1 line. This means your either using a splitter or home wiring to connect multiple phones. In these setups, it is quite common to experience voltage issues on the ananlog side which confuse people and make then think it is an IP issue. For testing purposes, I would connect just one phone directly to the RTP300 for a few days to prove if the splitter or home wiring as the cuplrit. I have seen these so many times over the past 5 years.

Posts: 6 · New Forum Member Joined: Nov 26, 2008 Posts: 6

VonTechMgr wrote:

What makes me this think this is what the root cause is because you mention you have a cordless and wired phone connected to 1 line. This means your either using a splitter or home wiring to connect multiple phones. In these setups, it is quite common to experience voltage issues on the ananlog side which confuse people and make then think it is an IP issue. For testing purposes, I would connect just one phone directly to the RTP300 for a few days to prove if the splitter or home wiring as the cuplrit. I have seen these so many times over the past 5 years.

Wow, I'm glad that I typed all that since you zeroed in on something I really thought was inconsequential. I have been using a splitter, and it's a pretty old one that's been in a box for a long time. We don't really use the corded phone anyway, so I've disconnected it and gotten rid of the splitter. We'll see if we notice any changes.

Posts: 32 · Vonage Forum Junior Joined: Nov 02, 2008 Posts: 32

Are you SURE it's your end? I have one frequent called inbound on Alltel cellular and I'd say 50% of the inbound calls don't hook up correctly. Everyone else has zero or almost problems.

Posts: 16 · Posted: Sat Nov 29, 2008 7:52 pm Post subject: i agree

I agree with VonTechMgr in his reply but it could also be your internet connection (even though there are some factors in your post that would potentially rule this out -- such as you should get a message from IVR and the internet connection quality would not come into play.)

BUT, on your computer open your browser (internet explorer or firefox, etc) and type into the URL bar: 192.168.100.1

if you are using a Motorola Surfboard cable modem you should see the diagnostic menu. click on the SIGNAL tab and see what the UPSTREAM, DOWNSTREAM, and SNR (Signal to Noise Ratio) are at. Your UPSTREAM needs to be between 35dBmV and 52dBmV. Your downstream should be between -12dBmV and +12dBmV. Your SNR is should be around the mid to high 30db's.

FOR EXAMPLE, HERE IS MY PARAMETERS.

UPSTREAM: 46.9dBmV
DOWNSTEAM: -2.7dBmV
SNR: 37.9db

just check it to rule out any poor quality internet connection.

Posts: 6 · New Forum Member Joined: Nov 26, 2008 Posts: 6

Pyramid3 wrote:

Are you SURE it's your end? I have one frequent called inbound on Alltel cellular and I'd say 50% of the inbound calls don't hook up correctly. Everyone else has zero or almost problems.

It's happening not just with my cell, but with my work phone, my wife's cell phone, and my electrician's phone. So I don't think all those other phones have problems.

Posts: 6 · New Forum Member Joined: Nov 26, 2008 Posts: 6

CommTech5 wrote:

...see what the UPSTREAM, DOWNSTREAM, and SNR (Signal to Noise Ratio) are at. Your UPSTREAM needs to be between 35dBmV and 52dBmV. Your downstream should be between -12dBmV and +12dBmV. Your SNR is should be around the mid to high 30db's.

FOR EXAMPLE, HERE IS MY PARAMETERS.

UPSTREAM: 46.9dBmV
DOWNSTEAM: -2.7dBmV
SNR: 37.9db

just check it to rule out any poor quality internet connection.

Thanks for that tip; I didn't realize you could query the modem like that. I have a Thomson cable modem, and the names are a bit different, but based on the values I think I have the right things:

Power Level (=UPSTREAM?): 46.7 dBmV
Received Signal Strength (=DOWNSTREAM?): 12.3 dBmV
SNR: 36.5 dB

This looks pretty comparable to what you've got. So I think the internet connection is good.

Posts: 6 · New Forum Member Joined: Nov 26, 2008 Posts: 6

VonTechMgr wrote:

This does not sounds like an IP issue. This sounds like an analog issue of the Off Hook signal not being detected by the RTP300 when your phone is picked up. This would explain why you don't hear the IVR message when you do not hear a dial tone due to you still have SIP registration and device does not know your phone is picked up. This is also why you hear phone ring on an inbound call but when you pick up, no Off Hook signal is detected therefore the RTP300 does not send back a 200 OK alerting the proxy that you have answered your phone and to start an audio session. This would cause caller just to go to VM or whatever your default calling feature is set to at that time.

What makes me this think this is what the root cause is because you mention you have a cordless and wired phone connected to 1 line. This means your either using a splitter or home wiring to connect multiple phones. In these setups, it is quite common to experience voltage issues on the ananlog side which confuse people and make then think it is an IP issue. For testing purposes, I would connect just one phone directly to the RTP300 for a few days to prove if the splitter or home wiring as the cuplrit. I have seen these so many times over the past 5 years.

I really thought you were on to it, and your theory that it's between the phone receiver and the vonage box makes a lot of sense, but even after removing the second phone and the splitter I'm still getting the problem. It actually did go away for a few days, but it's back now.

I don't want to replace the cordless phones on a hunch, and I don't have any backups. Is there anything I can do yet to verify?

Posts: 261 · Posted: Thu Dec 04, 2008 9:36 am Post subject:

You had reported more then one issue. Which issue returned after not occurring for a few days?

Posts: 6 · New Forum Member Joined: Nov 26, 2008 Posts: 6

VonTechMgr wrote:

You had reported more then one issue. Which issue returned after not occurring for a few days?

Thanks for checking in. The two issues of intermittently not being able to answer an incoming call, and not getting a dial tone right after not being able to answer a call, had both seemed to have gone away, but are both back.

97% of the time (rough estimate) if I pick up at a time other than right after not being able to answer a call, I get a dial tone. The other 3% of the time I can get a tone by power-cycling the routers. That's a problem, but it's not the one I'm focusing on right now.

I called Vonage Tech support last night and they put a debug on my vonage device. So the next time it happens, we can call in and they'll pull the log to see what happened.