Unfortunately, I think I've discovered the circumstances that these routers do not work well under. I have two sites under my management that have had no end of trouble with these routers. Here is the situation and the symptoms:
- both sites are ADSL2
- both sites have a single VPN connection to them as the responder
- both sites have appropriate ADSL2+ capable filters and short cables etc
- both sites drop their ADSL connection (not line sync) after 13 to 16 days and then fail to reconnect.
- A restart of the device (soft or hard) and the connection will stay up for anywhere between 5 and 16 minutes - whatever the time length is, it will always die after that time e.g. if it's 10 minutes, then it will lose connection every 10 minutes.
- both lines have been tested (and charged to the end user) by the carrier and the wholesaler and no line problems have been found. There are some very mild anomalies but nothing that should cause these sorts of issues
- both routers have the latest firmware, have been reset to default and still show the same errors.