Region : UnitedKingdom

Model : TD-W8968

Hardware Version : Not Clear

Firmware Version :

ISP : Zen

I recently switched to this combined router/modem (note the model number is AC1200, not as above -- the Archer D series doesn't seem to be available from the menu yet) from my old NetGear DG834PN to get better wireless and WPS, but I can't seem to get it configured properly.

That is, it works, but I've lost bandwidth by a significant margin.

Switching back and forth between the DG834 and the new one, I see the following, on average:

DG834 AC1200

Thinkbroadband TBB 9Mbps 4.5Mbps

Thinkbroadband HTTP x 6 10Mbps 9Mbps

BT BTP 11Mbps 8Mbps

scp [file transfer] 1MBps 500KBps

The BT site has so far been unwilling or unable to run the Further Diagnostics for me -- my exchange is Donaldsons, in Edinburgh.

I have a wired connection to the machine running the tests (using Chrome browser, Windows 7) and both devices report essentially the same "in principle" bandwidth:

Upstream Downstream
Current Rate (Kbps) 1272 10899
Max Rate (Kbps) 1343 12128
Upstream tests the same 1Mbps via both devices for both test programs.

I've tried both the TP-link wizard config and using Zen's recommended settings for 3rd-party routers, can't see much if any difference there, and no difference in performance.

Looking at the above numbers, it seems clear that the core hardware is probably OK: when the test software does multiple connections I get nearly the same results from both routers. But when I switch to a single stream, the performance drops by 50%, which suggests some kind of configuration problem.

I've run out of ideas, any suggestions of what to try/where to look next would be very welcome!