I have been using Siemens Gigaset A580IP for couple of months now. I find it works well with Nonoh.net, Voipbuster.com and Asterisks based system. Here is my brief review.
- Excellent voice quality.
- has both VOIP and land line option.
- Connects to multiple VOIP service providers (upto 6).
- Can easily switch VOIP provider.
- Can connect to corporate VOIP system based on Asterisks or other open standard based solution
- In expensive
- Runs Linux inside
What I don’t like:
- Setup take time initially, primarily because its slow to respond. But once its setup it works beautifully.
- You can’t dial another VOIP service provider directly, for example you can’t dial anyone on username@serviceprovider, you can only dial numbers. How ever you can receive calls if someone calls your email@example.com
- Cant connect to Skype, primarily because Skype uses a propriety protocol.
- Not a replacement for Skype video as it doesn’t do video.