Choppy voice chat

Peter Principle

When I try to talk to my friend online over gmail chat, or in game chat (e.g. Steam -> Left For Dead 2, or Borderlands (which is gamespy, iirc)), we get periods of clear communication, and periods of choppy cutting out. It will "stutter", cut in and out, like the mic is turning off and then back on every 1/4 or 1/2 of a second. It happens on my end, and on his end. We're both using Windows 7, and we're both on Comcast cable. And suggestions for how to go about trouble-shooting this?

TheKoolEagle

most likely packetloss, basically most voip programs send data via udp and if you have an overloaded network/node/dying router it could be dropping packets like mad. It sounds like its most likely a node issue since it only happens every once in awhile, if there is enough traffic passing through a node it can shit on your connection.

This is because UDP data is a straight shot, it is much quicker then TCP but cannot recover dropped packets, thus it has a much faster turn around time for communication.

I recommend trying to do a tracert to each others public IP address to see if anything is pinging terribly. Also what type of routers are you using? I know there is a router out there that treats voip applications as 'udp flood attacks' and filters a fuckton of udp packets.

Chances are you will need to talk to comcast about it, but finding out what end or both ends would probably be beneficial

bowen

Packet loss is the reason, though it sounds like whoever is giving you internet is doing some kind of packet shaping. You get that kind of nonsense with VoIP sometimes if someone's packet shaping your ventrilo packets, or skype, or steam voice chat.

Companies like Time Warner, Comcast, and Rogers are all notorious for packet shaping on things like bit torrent and the like.

End

I don't know about chatting over gmail, but with steam's chat, in my own experience sometimes it gets really choppy until you restart steam, at which point it is fine again.

Peter Principle

Thanks for the information. I need to do some reading, it seems.

Djeet

A couple of comments re: troubleshooting:

(1) Are either of you having this problem with gmail chat or in game chat with other users, or is it just between you two? It only takes one side of the conversation to have line issues (be it traffic shaping or overutilization) to ruin voice communication.

(2) Are either of you using your circuits for other things in the background while doing ingame/gmail chat (e.g. ftp, p2p, torrenting, usenet, video streaming, etc.)? This is also informed by other people (roommates, etc.) using the line. I have to pause my newsreader to play Netflix otherwise it's extremely choppy (unwatchable). I could tune my newsreader to play nice, but I haven't bothered to.

(3) It may take a bit of work, but a lot of routers have the capability to prioritize traffic by protocol/application or host; so you might look there as your first workaround. If your router does not natively support this kind of logic you might look into DD-WRT or tomato.

(4) Full duplex voice communication is probably the most susceptible type of data usage to degradation through overutilization or prioritization (there is no buffering like there is in streaming playback). You could be getting great throughput and latency on a line and still get choppy full duplex voice.

Peter Principle

That's a good point, I didn't think to check if the problem was all on his end or my end. Karl Popper, please forgive me.