How do I get full speed from BT Fiber 1GB Broadband

[dfunked]

900 is about the best you can expect on a 1G handoff with overhead, so you're good to go. On a LAN you can get it up to about 950 in some cases, maybe a tad more with jumbo frames) but the way shared fiber (which uses TDM) and L3 routing works adds some extra overhead beyond just L2 switching.

If you have 1G in both directions, as another person mentioned, QOS is not needed. I believe BT gig is 1G symmetrical (I work for them, but not in the consumer division so not positive).

They're 900 down 110 up for the top residential FTTP package.
But yeah, QoS still isn't really needed. I turned it off as soon as it was installed.

Oddly I never had to touch MTU settings. I get the full speed with the default of 1492 with QoS and AIProtection off. 910 via the router's built in speed test app, and very close to a gigabit on fast.com using a wired connection.

 

[Rimmel]

I was using ports 4 and 5 only (I just plugged them in randonly when setting up. I've changed the Port 5 to port 1 now. I'll see how it goes. Thanks

Didnt help

 

[L&LD]

What may help is if you physically unplug the router from the AC wall outlet (I would also unplug everything else going into the router too), and let it sit like that for a few minutes. This may 'reset' the ports.

When the router has fully booted up, I would plug in the LAN cables to 1 and 2.

Did you go and Withdraw permissions for everything in Administration, Privacy? And then reboot afterward?

I would also undo the changes you made to the MTU and MRU settings (with a reboot after that too).

Have you upgraded your firmware yet? 386.8 is available for your router now with good reports for it.

Note that if you've been toggling features on and off, it isn't the same as leaving (some of) them off.

A full reset may be in your near future (but be sure you've saved the backup config files, along with the firmware installer you're currently running first) after you have flashed to the latest version. With the backups you saved here, you can go back to where you are now very quickly.

Oh, are you able to verify the AC adaptor is working properly?

 

[drinkingbird]

They're 900 down 110 up for the top residential FTTP package.
But yeah, QoS still isn't really needed. I turned it off as soon as it was installed.

Oddly I never had to touch MTU settings. I get the full speed with the default of 1492 with QoS and AIProtection off. 910 via the router's built in speed test app, and very close to a gigabit on fast.com using a wired connection.

I have Verizon FIOS in the US and MTU 1500 works fine for me (the default on my router). As long as you aren't using a VPN or other encryption most ISPs should be able to handle that fine. Once you add a VPN client on the router, you may need to reduce your LAN MTU to prevent packet fragmentation and reduced throughput. Unfortunately it does not appear that the GUI allows changes to the LAN MTU size that I can see so would have to do it with a script. Though if the VPN client sets a proper MSS/MTU on the tunnels and PMTUD works correctly, your LAN devices should see that and adjust their MTU accordingly. That's a big "IF" though as I'm not sure if the Asus supports PMTUD and/or which VPN clients are smart enough to do that.

The best way to see if everything is working properly over a VPN is to fire up a packet capture and do a large download or speed test across your VPN. If the packet sizes are like 1444 or lower then it is properly adjusting the MSS and should not be any fragmentation, but then you can take it one step further and do a ping with size 1444 (or whatever size you saw) and the DF bit set and make sure it doesn't get dropped.