said by steve1111:
I think this is a matter of codec and compression and loss of data. I'm quite sure that the problem is with the cell phones rather than the Voip phone; calls received from cell phones are noticeably worse than calls received from landlines. But people do insist on using cell phones. How do I manage with these calls?
During Hurricane Sandy cell phone service was poor to non-existent but now things are back to normal.
Are you having problems with all mobile phones or just one carrier? There can be a huge difference between providers.
There isn't much you can do about it, other than using the G.722 or G.711u codecs. I would avoid introducing any more compression than necessary.
I suspect the issues you are experiencing are on the mobile phone's side. One or more carriers in your area is probably over-compressing calls to increase capacity. Don't let impressive looking coverage maps make you think call quality on these networks will be perfect (sometimes larger carriers have more capacity issues, so they use more aggressive compression than smaller carriers). Combine this with a poor quality phone or handsfree device, and call quality is going to become very poor.