Welcome to the Cox Community
Our community is a collaborative place to learn about Cox products and services. Jump into the conversation today!
Messages
Selected Messages
New Contributor
•
Noise of voice ports of the Cisco DPC 3212
Recently, Cox sent me a Cisco DPC3212 to replace an existing cable modem. Prior to a swap, the phone service was as expected, crystal clear with no background noise. Added note, I took the opportunity to use the 3212 to replace both my separate voice and internet cable modems, providing 3.0 support. Good idea I thought.
I have now tried three different Cox provided DPC3212 boxes and have the same problem. Once the box is configured and loaded, my voice port (l1/l2) has a distinct background noise you can hear on the phone. You might call it an oscillator type hmm (not a ground hum), but very noticeable. As soon as you break dial-tone, the sound is there, hanging out in the background, and is present on all calls. Doesn't sound like signal interference or another external noise. But just in case, I moved it around a bit, powered off everything in the room, and finally, took the box off the network and outside. No change. Running on battery power, I plugged a telset in and the noise is still there! Again, the modem is disconnected from everything, but still alive on battery power and now I'm standing at the COX service center with the same noise still coming out on my telephone. Yes, I've tried multiple telephones, same result. The service center folks are clueless and suggested another box swap.
There is no question in my mind that the sound is being generated by the internal circuitry of the 3212, which in my experience, would point to either a configuration error (COX) or some type of bad/mis-installed or wrong part hardware problem (at Cisco, not COX).
Anyone else had a similar problem? Again, having done/used VoIP for years, so I am expected an absolute silent phone line when i break dial-tone. Of course, maybe COX now sells noisy VoIP?
Thanks..
StephanieA
Former Moderator
•
If you have already tried different phones connected straight to the modem and still continue to have noise on the line, I suggest having our phone department research the issue in order to get this resolved. Please email me at cox.help@cox.com.
0
0
Health_Edge
+5 more
Valued Contributor III
•
What was your phone modem before? Sounds like it's picking up outside ingress maybe? What happens when you force a reboot with the botton on the back? Does the sound go away during reboot? If so Im thinking firmware issue, if not, Im thinking shielding problem(hardware).
0
0
gordonr
New Contributor
•
I just exchanged my old modem for the same cisco model DPC 3212. I had very slight line noise with the old modem, Cox store said this new one would clear that up. It is much worse now, distinct annoying buzzing sound that callers and my family hear on both ends, whether we receive or place the call. Very loud, phone conversations very unpleasant. Did some limited troubleshooting nothing works. It seems the old method of troubleshooting inside wiring does not work with digital telephone. Any ideas. Thanks gordonr
0
0
Health_Edge
+5 more
Valued Contributor III
•
Thats because with "digital" telephone, the dialtone isn't coming from outside, but its coming from the modem itself. The modem takes the cable signal you connect to it and turn it into a phone signal that you then use a phone wire to either connect to your phone, or to the phone wires in your house. Sounds like a firmware issue to me if its happening to multiple people. What area do you two live in?
0
0
gordonr
New Contributor
•
Heath thanks for responding. I am in Northern VA. Is there any way to update the firmware and if so is that something the customer can do. Appreciate any help. This is really bad. Thanks
0
0
scheibs
New Contributor
•
The Northern Virginia area, near Reston. I would tend to agree on the firmware problem, or a configuration issue. The setup people at Cox initially had issues trying to get the phone port to work. They tried several "options" before it would work. Cox support has emailed me. Let's see what happens. Thanks!
0
0
ChrisL
Former Moderator
•
The firmware is actually automatically managed by our network so this wouldn't be something the customer would have access to. I checked your device and I'm not seeing any updates available.
0
0
KipK
Former Moderator
•
What gordonr is describing, noise with the old modem and the new, buzzing while talking, is more indicative of an actual line problem like a short, and we may need to place a service call.
But scheibs, based on the troubleshooting process you've gone through, the only thing we've concluded this can be is the built-in comfort noise generation feature that's a feature of the Cisco 3212 and 3925 EMTA as referenced in their data sheets here and here. It shouldn't be noticeable anytime other than when there would otherwise be silence.
0
0
gordonr
New Contributor
•
Working with Cox Tech, the conclusion was telephone line wiring problems. And by plugging in one of my answering machine phones directly into the new modem, the noise was eliminated. However by doing so I lost the use of multiple other phones that had been working just fine with no line noise with my prior modem. The prior modem had a line directly from the wall wiring plugged into it. So I followed the same protocol when hooking up new modem only to get all this line noise. As a result I have lost the use of 4 extension phones that used to work just fine. So I really am not convinced that the problem was solely with my internal wiring because it was noise free before but I don't have that kind of maintenance plan with cox to come in and fix the inside wiring. No more noise but not happy with fix. Thanks Gordonr
0
0