"Don't hang up, let me cut our internet..."

March 17, 2008 2:14 PM

Our wireless internet and our cordless phone(s) hate each other with the unbridled passion of a thousand suns.

Hi. My house-mate and I here in Portland get our telephone and internet service through Qwest.

We have DSL
(MenuMeters tells me that our maximum download rate seems to be about 170KB/s).

The internet info comes to us over the same line as the phone. Qwest provides us with an "Actiontec DSL modem with wireless gateway" (model #GT701-WG). We plug the phone line from the wall into the modem, and then plug our cordless phone into the modem. The idea being that the wireless modem will take the internet stuff and broadcast it out to our Mac and Windows laptops, while routing the telephone stuff to our phone.

Here's the problem: if we are doing anything with the internet
(loading a web page, downloading podcasts, uploading photos to Flickr)
the phone starts dropping out. And the more internet activity, the worse the problem—if you're talking to someone, you can hear them but they only hear every other word you're saying.

So it seems that the wireless modem signal is interrupting the 2.4 GHz's cordless phone's signal. (yet, interestingly, it only seems to affect our side of the conversation; we can hear the other person fine and if someone leaves us a message on the cordless phone's digital answering machine we get the whole message even if we're downloading a bunch of podcasts)

• We have tried switching the channels that our wireless modem broadcasts to, but that hasn't helped.

• We've plugged in a "splitter" and it has had no effect.

• Yesterday we tried a new 5.8 GHz cordless phone—one touted as having no problems with wireless internet—and it has the same exact problem. A PDF I found online [link to PDF] states the Actiontec GT701-WG "operates on a 2.4GHz frequency, similar to many cordless phones" Which puzzles me as to why we'd have the same problem when we tried a 5.8 GHz phone...

• we have also tried cursing profusely, to little effect

My question is this:

Is it possible that the Qwest-provided Actiontec GT701-WG is the weak link and that more recent routers might be more cordless-phone-friendly? My thinking is that if two different phones* and switching router channels hasn't worked, the only constant in the problem is the router itself.

I was thinking maybe we could just pick up an Airport or something, go back to our old reliable phone (a Panasonic LX-TG2431) and have better luck.

As a side question, any Qwest users out there who have done this? I just want to make sure that Qwest doesn't have some quirk that requires using the Actiontec unit.

* The two phones that we have used that have both had the problem:
- a Panasonic LX-TG2431 "2.4 GHz Gigarange"
- a 5.8 GHz phone from Radio Shack (model number 43-138)

posted by blueberry to computers & internet (10 comments total)

Do you have dsl filters on all the telephone lines that aren't connected to the modem?
posted by zabuni at 2:32 PM on March 17, 2008

Is Qwest providing you with traditional analog phone service, or are they providing VOIP service? I bet it's the latter; otherwise, they would have sent you a set of DSL filters for your phone jacks and there would be no reason to plug your phone into the router.

If it is VOIP, then the behavior you describe is to be expected: your phone calls are sharing Internet bandwidth with the other things you're doing, and because uplink speeds are slower than downlink speeds, your outgoing audio can't keep up while the incoming audio has no problem.

If it is not VOIP, it is very puzzling that a 5.8-GHz phone has the same problem, for precisely the reason that you mention.
posted by brianogilvie at 2:34 PM on March 17, 2008

Can you try a CORDED phone to narrow down the variables? Using a corded phone plugged into the ADSL switch, download lots of things online while talking. See what happens.

If things work fine with a corded phone, it's some kind of wireless interference, as you assume. But if the call still drops out, it's crappy DSL service. (DSL generally uses different wires (literally) for voice and data, but I've seen bad shielding mess this up. Filters, as Zabuni suggests, should be supplied by your SP.)

I have a bunch of VTech i5807 phones (5.8Ghz) at home and they don't cause problems with WiFi (2.4GHz-G) internet, or vice versa. The microwave, on the other hand, trashes both. :)
posted by rokusan at 2:35 PM on March 17, 2008

Brian has a good point too. I assumed it wasn't VOIP (why have ADSL if you don't use the voice part?), but if it is a VOIP service, it's just a pure bandwidth issue. The wired phone test I suggested would prove that, too.
posted by rokusan at 2:36 PM on March 17, 2008

Well, I'm probably wrong. Qwest's FAQ for the GT-701WG says that the phone port has a built-in filter.

I'd follow Rokusan's advice and try a corded phone. (You should keep one around anyway, to use during power outages.) If that gives you the same problem, try an external DSL filter. If that too gives you a problem, call Qwest and complain.
posted by brianogilvie at 3:01 PM on March 17, 2008

A 5.8 GHz phone can easily have the same problem as a 2.4 GHz phone, because many are 2.4 GHz in one direction and 5.8 GHz in the other. Try a DECT system -- it uses 1.9 Ghz.

Also, make sure that the phone is separated from the DSL modem by several feet; short-range interference can cause havoc. I had a router that wouldn't work properly if it was on top of the DSL modem, for example.
posted by kindall at 3:01 PM on March 17, 2008

Q. Do you have dsl filters on all the telephone lines that aren't connected to the modem?
posted by zabuni at 2:32 PM on March 1

By DSL filter do you mean that splitter thing (looking at the filter, it's called an "ADSL Filter")?
We only have one telephone; it's plugged into the splitter which is then plugged into the modem which is then plugged into the wall.
posted by blueberry at 3:06 PM on March 17, 2008

If your phone is plugged into the splitter (as opposed to being plugged into a VoIP phone port on the router, or into a separate analog telephone adapter box) then it's operating as a traditional analog phone, and the problem is indeed interference. Seconding kindall: using a DECT phone instead should fix it.
posted by flabdablet at 4:31 PM on March 17, 2008

Joining the fray to say DECT or a phone that is known to do 5.8 in both directions. We have this same problem with our 2.4s, and it's a known issue of sharing the bandwidth -- it so happens I can adjust the power on my router, and I can control the amount of interference by adjusting the power level.
posted by davejay at 11:38 PM on March 17, 2008

Thanks all, I picked up a Panasonic KX-TG1033S DECT cordless phone and so far it's working great.
posted by blueberry at 8:16 AM on April 2, 2008 [1 favorite]