ADSLGuide reports that BT has introduced source filtering on its IPStream based products, which is a security measure to stop IP spoofing. Sadly one UK ISP, Andrews & Arnold, has reported that the change hampers bonded ADSL lines.

No specific details are given as to exactly how a bonded ADSL connection is affected. Bonding is the process of taking two or more semi-separate broadband ADSL lines and linking them together for a faster overall speed.

Currently source filtering has not been rolled out across the entire network, but hopefully BT will look into the issue before it gets any worse. Several ISP’s, such as Easynet, also offer bonded solutions.