said by Zergle :The way it stands now, it sounds like there was a problem with voip.ms and that it could somehow not connect to that French number or maybe to any French number.
The customer could not connect to +3778XXX... The exchange was incorerctly marked as a "Premium Number" in our rate table. We fixed it. For those who don't know what premium numbres are are, google it. In VoIP, they are usually used for fraud and most VoIP providers don't allow calls to them.