PowerLine, poor performance, half duplex?

[Morty_UA]

Dear all,

I have 2 Netgear Powerline 500 adapters, which are necessary because of the floor plan of my small apartment.

The two Powerline adapters are used as a virtual ethernet cable between my ISPs cable modem bridge and my own Linksys EA6300 router. In other words:
ISP Modem --> Powerline segment --> Router --> PCs.

My Internet connection is 60Mbit downstream and 10 MBit upstream. With the Powerline segment in use, my downstream speed is cut in half, to around 30 MBit. But when I use Netgears management software, it says that the link between the Powerline adapters yields about 90 mbit, which ought to be plenty.

This is totally consistent and repeat-able. When I temporarily run a physical cable between the modem and router (for testing), I get 60 Mbit downstream. With a Powerline segment in between, the tools say that it has substantially more than 60Mbit available, but still my effective throughput is reduced to 30 Mbit.

(And no, I can't switch to using a cable, I'm not allowed to drill into the walls.)

Any ideas? Is Powerline only half-duplex or something? What else could explain the performance loss?

 

[CaptainSTX]

Search this site. There are discussions and how tos on trouble shooting Powerline.

For a start plug both Powerline adapters into a wall outlet. No extension cords or powerstrips. Then if possible flip all the circuit breakers except the ones used to power your router, PC and the two outlets where the Powerline adapters are plugged in. Make sure to unplug (not just turn off ) everything else on the circuits still on. Then see if your speed improves. If it does then some device, motor or power supply in your apartment is killing you speed and by the process of elimination you will have to find it.

If you can't find the problem in your apartment then it might be a neighbor since the entire building is probably fed off the same transformer and you probably will need to find another solution.

 

[azazel1024]

I am sure that the Netgear management tool is showing you the PHY rate, not the realizable speed.

That just means it is signalling at 90Mbps, minus overhead and packet loss. 33% realizable isn't too horrible considering powerline.

Powerline isn't that speedy and considering that you are in an apartment, that is actually pretty good considering the possible wiring situation. As suggested, move it off any power strips, try to put it on electricall quite circuits, try to have the adapters on the same circuit, or at least the same power phase.

Any/all of those may help speed things up a bit, but considering you are constrained by location already, you might not be able to change most/all of those.

Your other options are run a wireless extender from the modem to the router (or vice versa) or you can run the wire anyway, without putting holes in walls. Just use some cable staples around the periphery of the rooms.

Since it is a small apartment, unless they are very thick concrete block walls, you'd probably get much better performance by just having the router located at the modem or if it is an issue of connecting a desktop, locate the router by the modem and get a wireless card for your computer instead of hardwiring in to the router. You'd almost deffinitely have better bandwidth than the 30Mbps that powerline is getting you.

In general, powerline is best if A) Terrible wireless conditions B) long distances indoors without the possibility of running wires (like 50+ft and/or very solid masonry/lathe and plaster walls).

 

[CaptainSTX]

Personally I think you are selling Powerline short.

I use some old Ver 1 adapters that have a link rate of 85Mbps. When I run the utility to check them I normally get a rate of 25 - 45 Mbps. I live in a large apartment building.

I use them to stream my SlingBox, primarily on my LAN, and 95% of the time the Powerline connection works great. With 30+ nearby Wifi networks thats better than I can say for WiFin in my apartment.

In addition I purchased four Powerline adapters on e-Bay for $25 each and three of them have held up for five years.

If you can't get Powerline to work for you and MOCA isn't an option then you will have to try a wireless bridge. If at all possible avoid the temptation to use a wireless repeater.

 

[Morty_UA]

Thank you both for your excellent answers. I'll dig into it. Thanks!