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I'm using HomePlug AV2 600 devices to connect upstairs with downstairs (router is downstairs). A check with iperf shows bandwidth of ~100Mbps, and data transferred on the local network from downstairs to upstairs is transferred at about that speed. Good times.
But when I try to access the Internet from upstairs, maximum throughput is only 40Mbps. Bad times.
If I try from downstairs, I get the full 80Mbps that my Internet connection allows. This is really puzzling, as I know the HomePlugs are working faster than that for local data.
Here's what my setup looks like (the router is connecting to a fibre modem using PPPoE, everything has gigabit ports, and all testing was using wired connections):
+----+
| PC |
+-+--+
|
|
+---+----+ +----------+
| Switch +---------+ HomePlug |
+--------+ +-----+----+
|
Upstairs |
+-------------------------------------------------------+
Downstairs |
|
+-------+ PPPoE +-----------------+ +-----+----+
| Modem +-------+ Wireless Router +-----+ HomePlug |
+-------+ +-----------------+ +----------+
If I connect to the router downstairs (wired), then it works great:
+--------+ +----------+
| Switch +---------+ HomePlug |
+--------+ +-----+----+
|
Upstairs |
+-------------------------------------------------------+
Downstairs |
|
+-------+ PPPoE +-----------------+ +-----+----+
| Modem +-------+ Wireless Router +-----+ HomePlug |
+-------+ +-----------------+ +----------+
|
|
+--+-+
| PC |
+----+
If I wire the downstairs HomePlug straight to the modem, and setup a PPPoE connection from the Windows 7 machine upstairs, it also works as expected:
+----+
| PC |
+-+--+
|
|
+---+----+ +----------+
| Switch +---------+ HomePlug |
+--------+ +-----+----+
|
Upstairs |
+-------------------------------------------------------+
Downstairs |
|
+-------+ PPPoE +-----+----+
| Modem +-------------------------------+ HomePlug |
+-------+ +----------+
I've also tried plugging the HomePlugs in right next to each other on the same floor, and get the same poor results:
Downstairs
+-------+ PPPoE +-----------------+ +----------+
| Modem +-------+ Wireless Router +-----+ HomePlug |
+-------+ +-----------------+ +-----+----+
|
|
+----+ +-----+----+
| PC +-----+ HomePlug |
+----+ +-----+----+
So the issue is only there when connecting to the Internet through both HomePlugs and the router, and only affects WAN traffic. I've tried replacing the router with a newer model, but get the same result. I also tried replacing the HomePlugs with a different brand (first tried Solwise, now Devolo).
I've also tried creating a PPTP VPN tunnel between my upstairs computer and the downstairs router - and this does inexplicably gives me the full bandwidth I would expect. But this relies on using DD-WRT on my router - and it's very flakey.
I'm at a loss, so any help would be much appreciated!
Cocowalla
Posted 2014-07-21T20:55:19.747
Reputation: 300
What speed do you get from the Upstairs PC, through upstairs switch, both HomePlugs, through the wireless router's LAN-side switch, to a machine plugged into a LAN port on the wireless router? Now take the downstairs machine and plug it into the WAN port of the wireless router instead of the modem (e.g. use static IP addresses to set up a point-to-point Ethernet WAN link; be sure to leave NAT on, but turn PPPoE off); what speed do you get from that WAN-connected machine all the way to the upstairs PC? – Spiff – 2014-07-26T05:09:48.603
@Spiff for the 1st part, speeds are ~100Mbps. I hadn't thought of trying the 2nd part, which seems like a good idea. But I can't get it to work in DD-WRT.. even tho I set a static IP, the downstairs machine still ends up with a default IP address (169.x.x.x or whatever) – Cocowalla – 2014-07-28T15:40:29.070
Your router won't serve DHCP out the WAN port. You have to give your WAN-connected machine a static IP on the same subnet as the static IP you gave your router, and set its default gateway to the static IP you gave the WAN port of the router. – Spiff – 2014-07-28T16:20:21.510
@Spiff that's exactly what I tried, but for some reason the machine still behaved as though it was attemping to get an IP via DHCP, and
ipconfigshowed a default '169.x' address instead of the static IP visible in the adapter settings. – Cocowalla – 2014-07-28T19:02:10.597