multiple Powerline networks attached to same router...this should work right?

[Samir]

OK, gotcha...that sounds completely correct to me now. VLANs are basically a 'network' that exists on level 2 (MAC), instead of level 3 (network) so the broadcast traffic from a VLAN is therefore not filtered out by the router from crossing over to another network which would normally be the case.

I'm not sure if that's correct. Broadcast or any type of traffic can't go between vlans without some sort of routing enabled between them. However, the broadcast traffic on a single vlan would be broadcast to that vlan.

So the power of vlans is that you can have more than one lan on the same cable (two vlans on the same port). And what's cool is that PL adapters keep the vlan information so you can have say 2 vlans on one port and the power line adapters will retain those vlans even though it's going over powerline now vs ethernet cable.

 

[sfx2000]

So now let's apply some of that to what you are doing with the PL adapters. Normally the PL have one single network, and hence one collision domain. When you segment the PL network into three networks, you essentially have created a 'switch' of sorts using the PL adapters. The one thing to note that's different than a normal switch which increases the aggregate bandwidth, is that in the PL network, all the different PL networks still share the same bandwidth pool.

So once you have three different powerline networks that cannot communicate with each other, the only way each of those networks can communicate with each other is via the switch on the Zyxel. Essentially, this would take any previous intra-PL network transmissions and force them to go through the Zyxel's switch if they are now between different PL segments. Switching isn't taxing at all, so even a badly performing Zyxel should handle this easily. But routing these (over the Internet or otherwise) may more taxing or less taxing or maybe the same--only a test will tell.

Interesting point - recall however that PLC at the physical layer is a scheduled MAC with a master coordinator - and each station within that PLC group speaks in turn... from a scheduling perspective, it's similar to Token Ring within the PLC group....

From my interpretation of the HPAV2 specs, having multiple disparate groups on the same, for lack of a better work, grid, basically turns into a time-domain problem - the two group master controllers are supposed to coordinate, and this is not at the ethernet level (which puts paid to the comment about the ethernet switch being coordinator, it's not, as that is one layer higher in the stack)...

So going back to my comment above - it's better to have a single group of many, rather than multiple groups (each containing a pair).

 

[Steve Sybesma]

Thought I would update you. I got my DrayTek Vigor 2860ac and VigorAP 902 all setup on Centurylink VDSL2, plus divided the 6 powerline adapters into 3 separate networks. Everything works beautifully. Only thing is that the utility that comes with the powerline adapters is designed to work with only the first PL network it finds. It will see the others if you isolate them by disconnecting the other two and leaving only one plugged in.

I think that segregating them that way is a good idea, because for as many of them as I had on the original setup (one master plus 4 slaves - with the 6th being a spare I kept on standby) I feel the one master PL adapter was getting overwhelmed by having so many devices connected to it. Now three of them are sharing the load. I have no issues with connectivity on any of them. I could do a test and disconnect two of the masters and see if data leaks from those two PL networks into the one that still has the master plugged in, but I doubt that it will. Setting up passwords for each PL network effectively isolates them from each other and the data all goes into the router and then travels to the other PL networks from there, as it should.

Everything is so much better now. I have at this point 30 of my devices attached to my network. Streaming services like SlingTV no longer suffer several-seconds long interruptions and the resolution doesn't even get fuzzy at times as it did before the new router. Very solid now. The quality is like having DirecTV (which I stopped about 18 months ago). One other change I made was that most of my streaming devices (which are in the living room) now go through a long CAT 7 directly to the router instead of through a PL adapter. The other rooms are all PL-connected. Even so I was having persistent connectivity problems in those rooms before and no more now.

 

[Samir]

Interesting point - recall however that PLC at the physical layer is a scheduled MAC with a master coordinator - and each station within that PLC group speaks in turn... from a scheduling perspective, it's similar to Token Ring within the PLC group....

From my interpretation of the HPAV2 specs, having multiple disparate groups on the same, for lack of a better work, grid, basically turns into a time-domain problem - the two group master controllers are supposed to coordinate, and this is not at the ethernet level (which puts paid to the comment about the ethernet switch being coordinator, it's not, as that is one layer higher in the stack)...

So going back to my comment above - it's better to have a single group of many, rather than multiple groups (each containing a pair).

Very interesting how powerline is like token ring in terms of scheduling. I've never delved into the inner workings of PL technology, so this is pretty neat.

Now that the OP has the new Draytek, I concur with you on the single group. It would have been an interesting experiment to see if isolation helped the dying router.

 

[Samir]

Thought I would update you. I got my DrayTek Vigor 2860ac and VigorAP 902 all setup on Centurylink VDSL2, plus divided the 6 powerline adapters into 3 separate networks. Everything works beautifully. Only thing is that the utility that comes with the powerline adapters is designed to work with only the first PL network it finds. It will see the others if you isolate them by disconnecting the other two and leaving only one plugged in.

I think that segregating them that way is a good idea, because for as many of them as I had on the original setup (one master plus 4 slaves - with the 6th being a spare I kept on standby) I feel the one master PL adapter was getting overwhelmed by having so many devices connected to it. Now three of them are sharing the load. I have no issues with connectivity on any of them. I could do a test and disconnect two of the masters and see if data leaks from those two PL networks into the one that still has the master plugged in, but I doubt that it will. Setting up passwords for each PL network effectively isolates them from each other and the data all goes into the router and then travels to the other PL networks from there, as it should.

Everything is so much better now. I have at this point 30 of my devices attached to my network. Streaming services like SlingTV no longer suffer several-seconds long interruptions and the resolution doesn't even get fuzzy at times as it did before the new router. Very solid now. The quality is like having DirecTV (which I stopped about 18 months ago). One other change I made was that most of my streaming devices (which are in the living room) now go through a long CAT 7 directly to the router instead of through a PL adapter. The other rooms are all PL-connected. Even so I was having persistent connectivity problems in those rooms before and no more now.

Glad you got everything working smooth. One thing that may be causing some hinderence though is having those three PL networks on the same grid as mentioned above. Once you push the 3 networks, the master coordinators may have problems inter-coordinating and you may see some strange stuff. I'd try to have everything on a flat network (one PL network) and see if you see any difference in performance. You shouldn't, and if you do, then your current setup may be better.

 

[Steve Sybesma]

Hello Samir,

I'm not seeing any ill-effect from having 3 separate PL networks attached to my router. Only positive. All devices at the end of each PL node (which is terminated with a ZyXEL GS1900-8 switch) are operating perfectly solid. I was watching a Roku connected to one of those switches connected to one of the 3 PL networks. No interruptions or stutter whatsoever. I should point out, there is no direct communication between the three PL networks. I have monitored the capture of all network traffic with Wireshark and didn't see anything strange going on. At this point my reason for leaving things in place would be that having a sole master with 20 devices seems like an overload (that's the setup I had before). I don't think PL networks were designed to have as many devices attached to one master as I have. Perhaps 5 to 10. The feel the master becomes a chokepoint more than the powerline medium itself when you have too many devices attached to it.

 

[System Error Message]

It is possible to gain more "channels" on powerline adapters but it is dependent on house wiring.

With powerline its best to use the most recent ones like AV2. To get more "channels" the house needs to be wired in such a manner that there are segments such as multiple grounds and terminations. This will be complicated as you would need a room where each socket has its own ground and that ground must be shared with a particular room or plug/elsewhere, same with the fuse boxes, etc. I dont think houses are wired like this.

With powerline it is all shared, think of it like a wifi with a single AP where everything is connected to that 1 AP. The difference is that powerline doesnt have as much interference or traffic as wifi as wifi is affected by interference and traffic that isnt yours that overlaps with your channel. Powerline latency is also better than wifi. Lowest i get is 1ms while the most i get is 5ms on AV2000 and this is even on a bad day such as when im getting 400Mb/s instead of 800Mb/s. I noticed powerline speeds do fluctuate a lot but the speed you get is more consistant than wifi for the throughput shown and so is the latency. With wifi as the traffic increase so does latency even when the bandwidth isnt fully used.

There are things that dont operate well with powerline. Switch mode PSUs do introduce interference but a good powerline adapter would have a filter so plugging those things behind the powerline can help with throughput. You could also plug those interfering devices into power strips that also have a filter. Measuring equipment could also cause interference with powerline and is very apparent with oscilloscopes.

 

[Samir]

Hello Samir,

I'm not seeing any ill-effect from having 3 separate PL networks attached to my router. Only positive. All devices at the end of each PL node (which is terminated with a ZyXEL GS1900-8 switch) are operating perfectly solid. I was watching a Roku connected to one of those switches connected to one of the 3 PL networks. No interruptions or stutter whatsoever. I should point out, there is no direct communication between the three PL networks. I have monitored the capture of all network traffic with Wireshark and didn't see anything strange going on. At this point my reason for leaving things in place would be that having a sole master with 20 devices seems like an overload (that's the setup I had before). I don't think PL networks were designed to have as many devices attached to one master as I have. Perhaps 5 to 10. The feel the master becomes a chokepoint more than the powerline medium itself when you have too many devices attached to it.

That is interesting on the performance hit because of 20 devices over powerline. Is this because you had 20 PL units, or just 20 devices on the network connected via powerline?

Have you tried the 20 devices straight on one powerline network with the new draytek? Because in theory it shouldn't behave any differently than the 3 PL network setup you have now. I'd be very interested if you've discovered a weakness on PL's expandability.

 

[sfx2000]

With powerline it is all shared, think of it like a wifi with a single AP where everything is connected to that 1 AP. The difference is that powerline doesnt have as much interference or traffic as wifi as wifi is affected by interference and traffic that isnt yours that overlaps with your channel. Powerline latency is also better than wifi. Lowest i get is 1ms while the most i get is 5ms on AV2000 and this is even on a bad day such as when im getting 400Mb/s instead of 800Mb/s. I noticed powerline speeds do fluctuate a lot but the speed you get is more consistant than wifi for the throughput shown and so is the latency. With wifi as the traffic increase so does latency even when the bandwidth isnt fully used.

The one upside about PLC is that the physical medium access is scheduled - each node gets a fair time to transmit, and only that node is allowed to transmit in that time slot - this cuts down on collisions in a big way...

I'm running AV1200 on a 40 foot span, and it does cross a breaker, so there's a bit of loss there, but it works well enough with reported PHY speed of 400-500 Mbs, and real world TCP/UDP bandwidth around 110-120 Mbps... latency is remarkably stable (see below)

iperf3 -c 192.168.1.20 -i1
Connecting to host 192.168.1.20, port 5201
[ 4] local 192.168.1.115 port 49502 connected to 192.168.1.20 port 5201
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-1.00 sec 12.8 MBytes 107 Mbits/sec
[ 4] 1.00-2.00 sec 14.1 MBytes 119 Mbits/sec
[ 4] 2.00-3.00 sec 14.3 MBytes 120 Mbits/sec
[ 4] 3.00-4.00 sec 14.4 MBytes 121 Mbits/sec
[ 4] 4.00-5.00 sec 14.4 MBytes 121 Mbits/sec
[ 4] 5.00-6.00 sec 14.5 MBytes 122 Mbits/sec
[ 4] 6.00-7.00 sec 14.3 MBytes 120 Mbits/sec
[ 4] 7.00-8.00 sec 14.6 MBytes 122 Mbits/sec
[ 4] 8.00-9.00 sec 14.5 MBytes 122 Mbits/sec
[ 4] 9.00-10.00 sec 14.4 MBytes 121 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-10.00 sec 142 MBytes 119 Mbits/sec sender
[ 4] 0.00-10.00 sec 142 MBytes 119 Mbits/sec receiver

iperf3 -c 192.168.1.20 -i1 -R
Connecting to host 192.168.1.20, port 5201
Reverse mode, remote host 192.168.1.20 is sending
[ 4] local 192.168.1.115 port 49504 connected to 192.168.1.20 port 5201
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-1.00 sec 14.5 MBytes 122 Mbits/sec
[ 4] 1.00-2.00 sec 19.8 MBytes 166 Mbits/sec
[ 4] 2.00-3.00 sec 20.3 MBytes 170 Mbits/sec
[ 4] 3.00-4.00 sec 21.0 MBytes 176 Mbits/sec
[ 4] 4.00-5.00 sec 20.7 MBytes 174 Mbits/sec
[ 4] 5.00-6.00 sec 20.7 MBytes 174 Mbits/sec
[ 4] 6.00-7.00 sec 20.7 MBytes 173 Mbits/sec
[ 4] 7.00-8.00 sec 20.5 MBytes 172 Mbits/sec
[ 4] 8.00-9.00 sec 20.9 MBytes 175 Mbits/sec
[ 4] 9.00-10.00 sec 20.9 MBytes 176 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 201 MBytes 169 Mbits/sec 0 sender
[ 4] 0.00-10.00 sec 201 MBytes 168 Mbits/sec receiver

 

[Samir]

Have you tried multiple threads? (The -P switch, I use -P3). I've found this can sometimes increase the throughput. It also shows that you need multiple things going on to maximize the network.