Originally Posted By: Quattro Pete
Originally Posted By: linksep
if you have fiber/DSL it will probably be much better.
What if it's DSL over a POTS line?
The max I can get from ATT at my place is 12 Mbps down / 1.5 Mbps up. While this should be plenty for reliable VOIP, my issue is that often times I'm on the phone and also screen sharing from my PC. Screen sharing can saturate the upload bandwidth easily, which will make the VOIP quality suffer unless you have configured some effective QoS on your router, but even then I'm skeptical.
The reason I say to stay away from cable is to get better (lower)
latency , typically DSL will have lower latency than cable.
Your bandwidth of 12M/1.5M is enough to have 23 simultaneous phone calls using G.711 (standard POTS call quality) or G.722 (double the call quality of POTS) the kicker is G.722 only works if you're making an end-to-end VOIP call using G.722 capable hardware.
Yes you need to do some advanced QoS setup to make sure VOIP traffic is always given a higher priority than other traffic, and you have no control over QoS once the traffic has left your modem; but call quality issues are way more likely to be caused by you saturating your line with other traffic than general traffic on the internet.