I have a number of VPNs set up at various sites which transmit data from printers and scanners to our server at the main site. The server processes the data and sends the print jobs back to the printer. Broadband types vary but our main site runs on EFM. These VPNs have worked fine for two years and all of a sudden are suffering from poor performance or are stopping altogether. We have a fail over line which is standard ADSL, moving the VPNs to this line increases performance. Can anyone help?

*bump*

Well, if the hardware is the same and all you're doing is swapping between EFM and ADSL then surely the most obvious thing is the EFM line has some sort of problem and is dropping/mangling packets. Can you run a speed test on it ?