TD-W9960(EU) v1.2 (setup in Bridge mode, wireless disabled) stops forwarding packets for around 5 seconds every few minutes.  It might do this twice in one minute, and then not for another ten minutes, the occurence is random, but the duration of dropped packets is almost always 5 secs. 

The line itself never drops according to the ISP (Andrews & Arnold - UK ISP).  The ISP performs 1s LCP echos, and regularly sees 1-2% loss from their side.

We've only recently narrowed this down to the TD-W9960, as I thought it unlikely to be this device as it is acting only as a DSL bridge.  I have a Mikrotik acting as PPPoE endpoint and firewall on the ethernet side.  Restarting the PPPoE or the Mikrotik itself does not fix the issue whereas restarting the TD-W9960 does fix the issue, but only for 6-12 hours.

Is this a known issue / is there a firmware update to this device of which I'm not aware.

Any assistance gratefully received.

Paul