colleenw may be referring to reducing VoIP bandwidth.
The trouble with HN is that its VoIP support is mostly erratic to nil - Like stardust13 said, it works OK for some users some of the time, for a few most of the time, still others none of the time. It's the luck of the draw, depending on what satellite/transponder you're assigned, time of day, what your computer is doing while you're trying to make a call, type of VoIP service you're using, and its bandwidth setting.
Both Net2Phone and Vonage have an optional low bandwidth setting, and you can adjust it down in a control panel online. By default, they're both normally set to high bandwidth. Net2Phone at low bandwidth (G729 codec) uses 16 to 20 Kbps, and "seems" to work a little better over satellite than others, and is the service we'll install with VSAT systems. Skype states it needs a minimum of 30 Kbps but recommends 100.