Nobody is addressing the quality and speed aspect. I'm not a network expert, but I'll give it a shot.
Check the quality of your internet connection here:
http://myspeed.visualware.com/index.phpTry Voip and Quality options.
Select the G711 codec
This is my summary for comparison:
VoIP test statistics
Jitter: you --> server: 0.5 ms
Jitter: server --> you: 3.4 ms
Packet loss: you --> server: 0.0 %
Packet loss: server --> you: 0.0 %
Packet discards: 0.0 %
Packets out of order: 0.0 %
Estimated MOS score: 4.2
Try different sites. The results will vary.
Check your internet speed here:
http://www.speedtest.net/index.php?nojs=1Do you have a quality problem?
Is your internet speed close to your ISP plan?
If problems:
You can try changing cables.
Don't use cheap cables from Ebay.
They should be rated at least Cat5E.
If you have Cable service does your modem support DOCSIS 3.x?
DOCSIS 2.x only supports 1 channel.
DOCSIS 3.x supports multiple channels.
This probably won't help unless your service plan is around 40Mbps or higher.
Each channel supports 42.88 Mbps, so I don't know if multiple channels will help throughput on a slower connection.
Edit:
Are you using an OBiWiFi dongle?
If yes, you can try a hard wire connection to your router.
Don't forget to check the cable between the router and modem.
If you have cable service, make sure all the coax connections are tight.
Try not to use any splitters.