It can and will I’m sure when routing as normal. The suspect is the PPPoE session. Just suggesting you prove that is the cause.
Thats why I asked what BT router you had. The Business hub 6 used to have a bridge mode:
Or you could temporarily port forward TCP 30215 and UDP 4500 from the BT router to your B380 WAN to keep your SpeedFusion Sessions running while you test.
Tomorrow evening I am planning to bridge-mode the bt modem-router at two sites where we have 900mbs fttp.to check if it is the pppoe code in the B380 that is not keeping up with the fibre traffic.
Well … we now have 2 sites that have the new 900mbs fttp circuits with B380 HW6 connected and the speed never goes much over 300mbs . if we connect the BT Smart Hub2 we get more than 900mbs.
We cannot set bridge mode on the BT Smart Hub 2 to test pppoe from the Peplink thru the BT modem,
they have removed the bridge mode option. BT said there is no point in trying an earlier version of the hub ( to get bridge mode ) since the earlier versions won’t process the speed of the new circuits.
So it looks like we need new peplink firmware to process the fibre speed.
It does seem like using PPPoE affects throughput. You should log a ticket and let us track it here. With Remote Assistance enabled I’m sure the engineering team can find an answer… .
A clean workaround would be to order a /29 IPv4 block for each line from BT, and have them configure your Smart Hub to route those IPs without NAT (and I’d probably turn off the firewall features in the hub at that point too). You’d then just configure a static IP on the Peplink like any other Ethernet WAN and leave the BT hub to terminate the PPPoE.
As Martin says I’d open a support ticket for this, as there seem to be a few other threads lately relating to PPPoE performance at high speeds. PPPoE will always add some overheads, but the performance loss you are seeing is quite significant and needs looking into as these types of connections are becoming quite common in a lot of places now as cheap alternatives to traditional ethernet leased lines or as low cost backups.
FWIW regarding MTU and PPPoE, in the UK any service delivered via the Openreach network should be capable of carrying a full 1500 byte payload thanks to them deploying RFC4368 (aka baby jumbos) across their network, bit sad if BT dont configure their own hubs properly for this as my FTTC service via Zen runs at 1508 MTU on the interface terminating the PPPoE (not a Peplink device) and that allows me to get the full 1500 bytes once the PPPoE overheads are taken off.
I now have an open support ticket and have been advised that the best possible is 700mbps which falls far short of 1gbps.
So it would seem that the WAN port can only ever far under perform the advertised speed.
Peplink tech. support would now like more details regarding the speed tests used ( which unfortunately will not progress the Peplink under performance.
BT have advised that we will notice the fibre speed to be in excess of 1 gig at times ( if we use their Smart Hub 2 )
For clarity are they saying 700Mbps with PPPoE being done on the 380, or with the BT Hub doing the PPPoE and the 380 using a plain routed IP interface?
Really? I would love to know how they make that claim with a straight face that given it’s a service capped to 900Mbps down and the router only has gigabit ethernet ports (we wont even go into the use an 80MHz 5GHz wireless channel etc…, unless they are claiming 900 down + whatever the upload as aggregated max throughput… I’d just pretend they hadn’t made that comment.