I have had a Voip phone supplied by Vox Telekom for about 6 months. The service is erratic at best. Most times you can hear people but they cannot hear me. This is simple - the upload speed is not sufficiently fast to carry voice data. Download speeds are generally ok which is why I can hear the other person. For the last few weeks the service is not working at all in that it is impossible to have a conversation. Now after spending hours online with various technical support staff I get phoned today by someone who acknowledges that the problem is with the Yahclick satellite connection and they are aware of the problem and working on a solution! This is only what I have been telling them for months now. Fantastic but in the meantime they continue to charge for a service that does not work.
So my advice to anyone out there is do not go for this 'service' as it is extremely unreliable.