Windows Zero Configuration is a real boon to the world of WiFi connectivity. I let WinXP and Vista take care of connecting to the right router and managing all that "stuff" for me and I've never given it a thought.
However, I've started using a different VoIP solution at home and for various reasons it's not plugged into a wired machine but living off a WiFi connected box (if I can work out the audio driver issues on the server it's going back to there, but I might end up having to wire the machine it's on at the moment)
So... what's the problem?
It was a tricky one to find... Every minute or so on a call I'd get a moment of total silence. I couldn't hear anyone, and no-one could hear me. Weird huh? That's what I thought.
So I started investigating. Lots of diligent diagnostics and pleas to the internet search gods and eventually I got a pointer in the right direction.... every 60 seconds Windows ZeroConf checks the health of the connection... sadly that has an impact on the communications to the router:
Reply from 192.168.10.1: bytes=32 time=1ms TTL=64
Reply from 192.168.10.1: bytes=32 time=1ms TTL=64
Reply from 192.168.10.1: bytes=32 time=1ms TTL=64
Reply from 192.168.10.1: bytes=32 time=944ms TTL=64
Reply from 192.168.10.1: bytes=32 time=1ms TTL=64
Reply from 192.168.10.1: bytes=32 time=1ms TTL=64
Reply from 192.168.10.1: bytes=32 time=1ms TTL=64
So what's the answer?
Well... in WinXP you need to kill the ZeroConf service (hit "Start", then "run" and type "Services.msc" and hit enter. Search for "Windows Zero Configuration...." and hit the "stop service" button) - or if you have a driver/management program for your WiFi card use that instead.
In Vista it's a little tricker
- Open a command prompt using run as administrator.
- Make sure the WLAN service must be running first. If it isn't type net start wlansvc.
- Type in netsh wlan set autoconfig enabled=no interface="name of your wireless network here" (with the quotes)
- If you need to see the name of your wireless network first, type in netsh wlan show settings
or (and if you have a group policy set that won't let you run that command) you can try this WLANOptimizer utility.
However there is a downside of turning off ZeroConf.... in my case when the machine that's running as the VoIP host loses the WiFi connection for any reason you have to restart the service, let it reestablish the connection and then shut it down again!
Hopefully, as this impacts both VoIP users and gamers (who need good ping times) we'll see a hotfix for Vista or someone will write a cool utility that softphones can trigger when in a call to stop ZeroConf doing it's check (perhaps extend the refresh interval to an hour from start of call or only if the connection drops or some other rule)
Oh, the VoIP solution I'm using is MagicJack. It's early days yet, but the quality blows Skype out of the water. If you're thinking about getting one check out the unofficial forum for some really good advice.