Building a E1.31 Show Network without breaking the bank.

[timon]

As I think we're virtually all in agreement that E1.31 is a mandate for large channel counts. So USB RS485 controllers are basically out of the picture. So how should we setup a network in order to run E1.31 without loosing any packets or having stability issues. Well, I thought I'd through my $0.02 in on how I think the network should be setup.

First, keep your home and show networks independent of each other. That doesn't mean that you can't pass data between them just make sure if you do there is a router or at least a level 3 switch between them. You don't want your home data interfering with your show network.

My recommendation is to have two network cards on your show computer. One tied to you home network and the other your show network. The one to your home network can be either WiFi or physical ethernet but the show network should be physical ethernet connection, only NO WiFi, and the show computer connection should be Gigabit Ethernet. Also, there is no reason to try and save a few $s on old 100Mbs switches. Get the latest as it should last you a few years. As I said don't use WiFi unless you absolutely have to due to interference from other networks. Stay with ethernet even if you have to run it a couple hundred feet as you'll be happier in the long run.

The Light Show network. A lot has been said about using unicast or multicast transmissions to the E1.31 controllers. In the past the only sensible solution was to use unicast as few if any low cost switches were available for under $600 to $1,000 that could handle IGMP snooping required to do multicast without any problems. Without IGMP snooping if you send multicast packets to the switch it will send those packets to EVERY E1.31 controller on your network which causes several problems. First, since almost every E1.31 controller we'll be using is only 100Mbs if your sending from your nice 1Gbs network off your show computer your going to totally overrun your 100Mbs connections to those E1.31 controllers. Can you say "Switch Kill"? Second, the E1.31 controllers had to sort out their packets from those going to the other E1.31 controllers which can overload the processor in the E1.31 controller which then causes unexplained errors with your display. This issue has already been reported on DIYC.

But that was then and this is now. Now Netgear's has their ProSafe Plus GS1xxE line of switches it's no longer a problem. These switches come with full IGMP snooping as well as several higher end features, such as VLANs, at a price that consumer are willing to pay.

Here is a list of the switches we should be able to use along with the current pricing from NewEgg. Other outlets might have a better price I'm just using them as an example.

Model	Ports	Price
GS105E	5	$45 after rebate
GS108E	8	$68 after rebate
GS116E	16	$175

Since these are fully IGMP snooping aware switches you should be able to run Multicast without any issues with either overrunning the 100Mbs port speeds or passing lots of unnecessary traffic to the E1.31 controllers. The IGMP snooping is enabled out of the box so you shouldn't have to change anything on the switch other then setting it's network address.

Which switch should you get? Well if you really think you won't have more than 4 E1.31 controllers I'd start wit the 8 post since it's only a few $'s more than the 5 port. The 8 port would give you 7 E1.31 controllers which should be enough for all but the largest shows.

Hope this helps and happy blinking lights to all.

John

[Barnabybear]

Spot on post – and glad that you made recommendations at the end.
I hope that subsequent posts that may differ in opinion will include recommendations as well.

[mrpackethead]

As I think we're virtually all in agreement that E1.31 is a mandate for large channel counts.

Might be flogging a dead horse, but Art-net is also a very valid way of doing large channel counts as well. Its DMX over IP, Similar ( but different ) from E1.31. The required networking skills to make it go are simpler, and it ace hives the same results. There are a few interesting advantages of E1.31 however. The professional world has much much wider support for art-net than for E1.31.. ANy of the controllers that are running E1.31 should easily also support Art-net, ( maybe need a firmware change )

First, keep your home and show networks independent of each other. That doesn't mean that you can't pass data between them just make sure if you do there is a router or at least a level 3 switch between them. You don't want your home data interfering with your show network.

This is a simple approach but certainly not the only approach. There are times and places that you just can't do this. Other considerations come into play, but it is not mandatory to do this, its just convenient sometimes. I often do this in my big commerical shows, but not for network traffic considerations.. Its because its sometimes just much easier not to have to connect ( and get permission ) from the corporate IT department... ( anyone in IT will know what i'm talking about )

My recommendation is to have two network cards on your show computer.

Again this is a convenience thing, rather than a mandatory thing. The one thing is does do is increase the complexity of the network setup. An equally valid ( more valid? ) configuration is just to have a single nic, and only have it connected to your 'show' network. If you've gone to the effort of isolating your network, why wouldn't you do this as well?

One tied to you home network and the other your show network. The one to your home network can be either WiFi or physical ethernet but the show network should be physical ethernet connection, only NO WiFi, and the show computer connection should be Gigabit Ethernet.

Why? Whats the issue with Wifi? Provided you understand the limits, wifi *can* be a viable solution. If you can get a clear channel, reasonable throughput and no big latency problems and its reliable then why is this a problem. I have six large trees across the road from home that have had e1.31 over wifi ( 2 universes ) running just happily. If you expect to push 100 universes down wifi you might just run into problems.. Arguable, wifi can be less relaible than wired. But if you had to run your cable across a road, that might not be the case, after the 700th car had driven over it... Horses for courses..

100M will carry *alot* of real time lighting data. i've personally pushed over 200 universes on it. The networking tolerances for using 100M ethernet are lower than for gigabit, and its inherently more reliable.. Would I go and buy 100M switches.. probably not. However unless you are hitting the 300+ universe mark, this isn't really an issue. For a properly compliant E1.31 network, port speed isn't the issue for a switch typically.. ( more below )

Also, there is no reason to try and save a few $s on old 100Mbs switches. Get the latest as it should last you a few years.

But if you've got some, you might be able to use them. DOn't just discard it because its 100Ms-1

As I said don't use WiFi unless you absolutely have to due to interference from other networks. Stay with ethernet even if you have to run it a couple hundred feet as you'll be happier in the long run.

- Used with care and understanding, you can be just fine.

[quote]
The Light Show network. A lot has been said about using unicast or multicast transmissions to the E1.31 controllers. In the past the only sensible solution was to use unicast as few if any low cost switches were available for under $600 to $1,000 that could handle IGMP snooping required to do multicast without any problems.
[quote]

What is the issue with using Unicast? its significantly simpler to understand and doesn't need a switch that will do IGMP snooping. Its a question of bottlenecks and simplicity.

First the bottlenecks;

If you are in the situation where all controllers on the network are receiving different universes, theres actually nothing to be gained 'network' wise with using multicast. Your 'media server' needs to craft and send a packet per controller.



If you have some universes which are required by several controllers, you can make a saving, your media server only needs to craft a single packet that will end up at multiple receivers.. With high powered media computers we seem to use, they can send a lot of packets before they bomb out though.. Ironically some very expensive consoles in the pro world do bomb out when you ask too much of them.

And the advantages.

The nice thing with multicast however is that you don't' need to do any kind of discovery / manual mapping of universes to IP address's. You don't need to tell your media server that Universe 33 is on Ip address 10.10.10.3 etc.. ( Art-net provides a polling mechanism to do this automatically, but its an added layer of complexity of course ).. In E1.31 universes turn up in multicast packets with know source address's. Ie, Universe 1 will always be in 239.255.0.1. So all you have to do is configure your device to use what ever universe you want, and your media server actually doe'snt need to know about the device at all. ( this a nice feature and really helpful on the big stuff )

Without IGMP if you send multicast packets to the switch it will send those packets to EVERY E1.31 controller on your network which causes several problems.

Might sound nit picky, but Its IGMP Snooping. Theres a very important difference! IGMP ( internet group management protocol ) is a LAYER 3 signaling protocol, between a end host, and its next hop router to communicate which 'groups' ( read multicast streams, or in our E1.31 case, which universes ) it wants to receive. IGMP Snooping is a system where the switch watches the Layer 3 information, to control Layer 2 forwarding ( i.e. switching ). For IGMP snooping to work, ( and work properly ) you still need a device on the network that will act as a IGMP querier.. THis typically is the next hop router. Without IGMP querys going on, IGMP snooping doesn't work. ( because there is no IGMP conversations being had! ).

Of course theres an exception to that rule, and *some* switches, also include the capability to turn on an IGMP querier.. I am not sure about these lower cost switches. they may or may not have this inbuilt.

First, since almost every E1.31 controller we'll be using is only 100Mbs if your sending from your nice 1Gbs network off your show computer your going to totally overrun your 100Mbs connections

only if your actually sending greater than the 100Mbs-1 ( technically a bit less ).. Your more likely ( especially on cheap switches ) to fill the port buffers first.. but 100M is the best part of 300 Universes.. If you're running 300 Universes, then you'll probably not be too worried about spending $800 on a switch to connect it together either?

Second, the E1.31 controllers had to sort out their packets from those going to the other E1.31 controllers which can overload the processor in the E1.31 controller which then causes unexplained errors with your display. This issue has already been reported on DIYC.

Much more important issue.

But that was then and this is now. Now Netgear's has their ProSafe Plus GS1xxE line of switches it's no longer a problem. These switches come with full IGMP snooping as well as several higher end features, such as VLANs, at a price that consumer are willing to pay.

Whats odd is that they did't bother to list this in their data sheet! However its the configuration guide..

Based on the IGMP query and report messages, the switch forwards traffic only to the ports that request the multicast traffic. "
( ftp://downloads.netgear.com/files/Pr...M_23Sept10.pdf )


You'll still need to have something running as the querier.. The good news that because we probably running these networks in a closed network we can use our media server to do the IGMP queries for us. Theres some IGMP querier software available for both windows and linux and mac. heres one for example ( http://www.coexsi.fr/publications/igmp-querier/ )

Here is a list of the switches we should be able to use along with the current pricing from NewEgg. Other outlets might have a better price I'm just using them as an example.

These should do the job, and they look well priced.. Im going to order one in and see if i can set up a 'known good configuration' and bring it back to you.

Since these are fully IGMP aware switches you should be able to run Multicast without any issues with either overrunning the 100Mbs port speeds or passing lots of unnecessary traffic to the E1.31 controllers. The IGMP is enabled out of the box so you shouldn't have to change anything on the switch other then setting it's network address.

And setting up a querier

Hope this helps and happy blinking lights to all.

John

Great thread.. Don't take it the wrong way, not knocking your post at all, just trying to add to it. Much of what you have said is good advise.. and if you only want to learn the minimum, doing things with extreme caution ( separate networks etc etc ) is a good way of avoiding lots of frustration when it goes wrong. ( Fixing multicast issues, can be a major headache )..


I wonder what other low cost switches support IGMP snooping these days..

[timon]

MPH,

I'll always take constructive criticism. Thanks for pointing out the missing "snoopings". I've corrected them to make sure there is no confusion.

I left out Arc-net and pixelnet since if the network was able to support E1.31 it should support the others without any issues.

One of my points was if you buying a switch anyway get one with the new features even if it cost a bit more. I'm just getting ready to replace my old hubs only home network with a GS116E and yes the house is fully wired with Cat5E. I'll add a GS108E for the show net.

My biggest issue with WiFi is interference from other networks in a residential environment. If your out where you don't have many networks around you then go for it. If your in a busy 2.4GHz area you can always go to 5GHz and likely not have any problems.

I missed that it's missing a querier but at least the software is available. I would thing that the function could be a included in the light show software or even in the LOR to E1.31 board.

Oh, minor issue with you post. You missed a "/quote" after a "quote" so one of my quotes is not quoted. You might want to do a quick edit

Again, thanks for the corrections.

John



Barnabybear,

Thank you

[wbottomley]

John, I picked up (2) gigabit 8 port switches between $20-$25 each.

Here's two sites to watch for deals like that...

Slick Deals | Fat Wallet

[mschell]

And to add to the thought...

Most likely the primary reason a light hobbyist would worry about IGMP snooping and level x switching is to "protect" a given controller from having to deal with too much traffic. Not all of the current E1.31 controllers respond to IGMP queries, so you might not get any benefits of putting switches somewhere in your light network. But most likely you'll see a problem with some lights not behaving correctly because a controller can't keep up with the number of datastreams going down the wire.

And there's no real reason not to put 2 or 3 E1.31 controllers on the same segment. The amount of traffic isn't too great to overload a controller with 8-12 universes of data going down that segment on the same switch port.

So if you plan on buying a switch or two, just plan on more than 1 controller per port. This means that if you have 5 or 6 controllers, you don't need to necessarily buy more than a 5 port switch.

Again, the goal is not to break the bank, and not to overkill the network or a controller.

I ran about 8 universes of traffic thru 2 E1.31 controllers this last season with a dumb 10/100 5 port switch without a hitch. A separate show network was used with a separate NIC. Given that prices have dropped, I'll probably look to use a more "intelligent" switch this next season, since I'll be adding 3 or so new E1.31 controllers.

[David_AVD]

So if you plan on buying a switch or two, just plan on more than 1 controller per port. This means that if you have 5 or 6 controllers, you don't need to necessarily buy more than a 5 port switch.

I don't follow this. Are you saying connect more than one (Ethernet input) piece of hardware to a given network switch port?

[mschell]

I don't follow this. Are you saying connect more than one (Ethernet input) piece of hardware to a given network switch port?

Sorry, sometimes my brain moves faster than the fingers can get it put down....

The intent was to say that you don't need an IGMP enabled, "intelligent" switch port for each E1.31 device. You can choose to have fewer ports on the "smart" device to segment the traffic, and then have a small, "dumb" switch or hub out in the yard that continues a given segment from one E1.31 device to another. Early in this journey, several folks suggested cheap $10-15 switches that could be powered by the same 5V as the pixels, and would fit inside the enclosure. This would cut down on cable length, since you wouldn't have to run a cable for each Ethernet device back to the main switch.

I would only suggest doing this for 2-3 E1.31 devices on each chain.

[DynamoBen]

First, since almost every E1.31 controller we'll be using is only 100Mbs if your sending from your nice 1Gbs network off your show computer your going to totally overrun your 100Mbs connections to those E1.31 controllers. Can you say "Switch Kill"? Second, the E1.31 controllers had to sort out their packets from those going to the other E1.31 controllers which can overload the processor in the E1.31 controller which then causes unexplained errors with your display. This issue has already been reported on DIYC.

Let me start by saying that this is very difficult to dissect in text but the above was most interesting to me (someone who develops this hardware). Most DIYC controllers are not 100Mb and they are usually less than 10Mb. What I mean by that is while the network interface might be 10/100Mb the amount of data consumed is more on the order of 1Mb. The way the devices sort out packets is by IP, in my case multicast address so I don't "see" any packets that I should not consume. This keeps the processor focused on processing real data, not tossing packets. This to me is the beauty of sACN over say ArtNet, I don't have to look at every packet to see if its for me.

On another point you mentioned the concern about dropping packets, I wouldn't worry too much about that. sACN is based off of DMX in that new packets are sent 40 times per second. Dropping packets here and there won't have a noticeable impact and really should be expected.

Having a proper network is a good thing, but I would hate to see people needless spend money on special network gear for their shows. If you only have a few universes of data your home network should be fine. If you have many more than a few then you might need to scale up.

[timon]

Let me start by saying that this is very difficult to dissect in text but the above was most interesting to me (someone who develops this hardware).

Sorry, I'll try to be clearer next time

Most DIYC controllers are not 100Mb and they are usually less than 10Mb. What I mean by that is while the network interface might be 10/100Mb the amount of data consumed is more on the order of 1Mb.

Unless the controller has set the Ethernet chip set to only connect at 10Mbs then it will connect at 100Mb when connected to a 100Mb switch. If it does it has to accept the data at that rate.

The way the devices sort out packets is by IP, in my case multicast address so I don't "see" any packets that I should not consume. This keeps the processor focused on processing real data, not tossing packets. This to me is the beauty of sACN over say ArtNet, I don't have to look at every packet to see if its for me.

I think you meant to say unicast because if it's multicast and your switch does not have IGMP snooping then the controller will receive packets for all controllers/universes since the switch doesn't know which port needs the data. With unicast then they'll only see the universes directed to their IP.

On another point you mentioned the concern about dropping packets, I wouldn't worry too much about that. sACN is based off of DMX in that new packets are sent 40 times per second. Dropping packets here and there won't have a noticeable impact and really should be expected.

Maybe yes, maybe no. Maybe it's just the 40+ years of engineering in me but I don't want any packets being dropped so I don't have unexpected results. It just goes against the grain.

Having a proper network is a good thing, but I would hate to see people needless spend money on special network gear for their shows. If you only have a few universes of data your home network should be fine. If you have many more than a few then you might need to scale up.

I don't see it as needless money spent considering the overall cost of the entire E1.31 hardware. Your talking less than $80 for a switch that can handle the traffic. It's a drop in the bucket and money well spent IMHO.

Also, and I didn't bring this up before and I should have, there is no way in Hell I want the network sitting out in my yard directly connected to my home network. The last thing I need is for damn jerk to plug their computer into it and bingo, their accessing data on my network.

John