Multicast, MixPad and Wireless.

iLive Archived iLive Discussions
1

Hello All

Background

This is quite technical, but below is a brief discussion of “Multicast” and its use with MixPad.

Multicast is a way of delivering messages across a network.

In normal circumstances a single message is sent from one machine to another machine across a network. This is Unicast.

Multicast allows a single message from one machine to be sent to many machines on a network.

This is achieved by a router making copies of the original message and sending it to all interested parties.

A more detailed explanation can be found here:

This makes multicast very useful for media streaming across networks, and Allen & Heath’s MixPad app can use this technology to transfer metering data from a Mix Rack to an iPad.

How does this affect me?

With multicast enabled, the wireless router in your network has extra work to do.

This overhead can exceed the processing power of older or less capable wireless routers.

This can make your MixPad application slower to use, or in the worst case not work at all.

So why use it?

Multicast has many benefits.

With multicast off, if a connected MixPad suffers a sudden signal drop, I.E walking behind a pillar, the responsiveness of all other connected devices will suffer. You may notice your iLive Surface metering will slow down / stop momentarily. With multicast on this is not a problem.

Using Multicast also means your Mix Rack spends less time sending metering data, which gives it more time to handle extra connections. This makes Multicast a good choice if multiple MixPad’s are in use.

What Hardware should I use / how should it be configured?

There are many different makes and models of wireless routers available and testing them all would be difficult at best. Allen & Heath have tested the following wireless router, with the latest firmware available from the hardware manufacturer:

Belkin PLAY MAX N600 HD

Allen & Heath will continue to test additional models but the above works correctly with Editor and a MixPad both connected wirelessly to a Mix Rack, which also has a physical surface connected.

Other considerations when configuring your router should include physical positioning of the device to provide best coverage at your venue.

Avoiding interference with other wireless networks will also help ensure good quality of service. A discussion on channel selection and 2.4Ghz vs 5 Ghz frequency selection can be found here:

https://www.microsoft.com/athome/setup/wirelesstips.aspx

Need Extra Help

Please contact Allen & Heath technical support if you need additional information.

Andy

A&H

2

Thanks for the breakdown.

I am curious if there are other features of this Belkin Router which attracted you all to it in the first place?

Primarily when I think of professional network equipment Belkin is near the bottom of my list, so I was wondering how you landed on it?

I have read some reports that people are having issues with Apple’s Bonjour service and this router. This worries me because bonjour is a multicast service as well. Obviously you are stating that you have tested this and it works well (this could also be a firmware issue on the other users parts) so I dont doubt you on that, just found it interesting.

Besides supporting multicast and having the power on board to deal with it effectively are there other specs we might look at in a router for better MixPad performance?

I have been using Apple Airport Extremes so far and seem to be getting really good results, as I am sure their multicast support is pretty strong considering Apple’s reliance on Bonjour for so much of its devices communications.

To that extent if there are multiple devices on the network broadcasting multicast signals can/will this bog down the routers?

Thanks again for the info and support you guys are amazing and I am loving the MixPad so far really makes things fun.

Stephen Tyler

Coordinator of Technical Operations

ACM@UCO

www.acm-uco.com

iLive T-112/iDR-32; T-80/iDR-16; iPhone; iPad

3

Hi Stephen,

Wireless routers seem to fall into 2 categories with respect to multicast traffic.

Type 1)

Most routers don’t really understand multicast and where to route it, so they just broadcast the traffic out of all ports simultaneously. This has a high overhead.

Type 2)

Does understand IP multicast, the standards to look for are IGMP V1 / V2. Every time a MixPad wants to start listening to multicast metering it “joins” a multicast group. IGMP compliant routers query and listen for group membership information and only send data to connections which need it. This lowers the overhead on the router.

From looking around the market there aren’t many Type 2 models out there. We’ve tested some that claim to be compliant, that actually have partial or broken implementations.

When you go and buy a new router, if it doesn’t mention IGMP or multicast, its probably a type 1. This is fine, but it needs to have enough horsepower to deal with replicating and sending all the metering traffic, and there is no standard for that!

Best advise is to look for a high end consumer unit that mentions media streaming.

If you want to go pro, you could give someone like Cisco sales a call but while most of their units I’m sure would cope with the traffic, most are not 802.11N, and you’ll pay double!

Perhaps someone could start a iPad hardware thread and share information about success and failure with different router hardware vendors ?

Hope this helps.

Andy

A&H

4

I’m wondering if this one would suit?

Billion 7800N Wireless n Modem Router + Gigabit Switch : https://www.billion.com/product/wireless/BiPAC-7800N-11n-ADSL2-Broadband-Firewall-Router-Gigabit.html

I need to buy a new router anyway, just wondering how much I should spend (my old one, which has been doing fine, was a basic $100 consumer unit)

iDR32 mixrack

MixRack for iPad & Tweak for iPhone apps

Asus N61 Laptop (x2 wireless)

Sennheiser IEM (for PFL)

Dante card (soon!)

5

Hi Adam

I wish we could defiantly say yes or no.

The BiPAC 7800N has IGMP snooping, which is a half way house between Type 1 and Type 2.

To paraphrase, “it’ll listen to IGMP traffic, but someone else has to generate it”

More info here:

So without a full IGMP capable router also on your network, it’ll probably run as a Type 1, which means it’ll need a good turn of speed.

Let us know how you get on.

Cheers

Andy

A&H

6

Right, it gets more complicated the further down the rabbit hole you go :wink:

Thanks for the info Andy, it gets good wraps overall and is definitely far better spec’d than my current router so I might give it a run unless anyone wants to suggest something they’re using that would be a better choice?

iDR32 mixrack

MixRack for iPad & Tweak for iPhone apps

Asus N61 Laptop (x2 wireless)

Sennheiser IEM (for PFL)

Dante card (soon!)

7

Great information.

I use both the Airport Extreme “N” and also the Airport Express “N”.

Very good results on all shows. I MAC address the mix rack, surface, touch screen, laptop (both wireless and lan addresses). Also have the option of connecting my T112 and iDR48 wirelessly, (just in case). My multicast is turned off. I have musicians for a few bands I work with, that have iphones which are both mac addressed as well running the itweak app.

I think I am going to wait for the new ipad. The rumor mill is communicating a new faster processor.

CRJ

Oswego, IL

T112 Surface

iDR48 Mix Rack

Sony F Series laptop

Win 7 500GB HD 8G RAM

iPad 2 and Dante soon

8

We use an Airport Extreme also without multicast currently. After an early issue that might have involved multicast back at 1.6 we turned it off.

112T/IDR48/IDR16

9

I’m using a TP-Link TL-WR1043ND router with some TP Link TL-ANT2408C omni 8dBi antennas, and this really works great, also because these antennas easily attach to a mic stand as they have a strong magnetic base.

The user guide states:

“DTIM Interval - This value determines the interval of the Delivery Traffic Indication Message (DTIM). A DTIM field is a countdown field informing clients of the next window for listening to broadcast and multicast messages. When the Router has buffered broadcast or multicast messages for associated clients, it sends the next DTIM with a DTIM Interval value. You can specify the value between 1-255 Beacon Intervals. The default value is 1, which indicates the DTIM Interval is the same as Beacon Interval.”

The latest firmware release note explicitly states “Add IGMP support” so this seems to suggest that this router supports multicast.

Tonight I’ll check if my router shows these settings:

https://www.tp-link.com/support/showfaq.asp?id=121

Wouter

10

Any suggestions with some proper, 19" rack mountable wireless routers?

11

Last summer, I was searching for a rack mount wireless router. There are a few in the market that are “business class” but also pricey. Cisco was the only brand (I found) you could purchase a separate rack ear kit that works with certain models. Many of the brands available are built for home and or small office settings. If you find one, please let me know.

CRJ

Oswego, IL

T112 Surface

iDR48 Mix Rack

Sony F Series laptop

Win 7 500GB HD 8G RAM

iPad 2 and Dante soon

12

Well, there is a company called Teqsas- https://www.teqsas.de/index.php?id=160&L=1

Hope to get a quote. I’m already using their inclinometer- so callesd LapTeq.

ddff

13

Thanks for sharing the link.

I went to the site and was looking for a spec sheet or a manual, and nothing was available but a sell sheet.

Not sure of the pricing, and you would think a company like Netgear etc, would offer something like this. Interesting.

CRJ

Oswego, IL

T112 Surface

iDR48 Mix Rack

Sony F Series laptop

Win 7 500GB HD 8G RAM

iPad 2 and Dante soon

14

UPDATE: received new feedback, see post on the next page.

Jus received feedback from TP Link regarding IGMP and multicast: a bit confusing however:

"Sehr geehrter Herr Tilkin,

IGMP liegt in drei Versionen vor. Die benötigte Multicast Funktion gibt es nur in Version 3 von IGMP. Wenn Sie diese Funktion benötigen, um t-home entertain nutzen zu wollen,muss ich Ihnen leider mitteilen, dass dies nicht möglich ist.

Mit freundlichen Grüßen

Mostafa Aziz

Technical Support Engineer"

In English: they say that multicast is only supported from IGMP version 3, which is unlike what Andy tells us, a bit confusing.

Wouter

My prayers have been heard, Dante is coming!

15

Hi Wouter,

I can’t explain their response.

I’ve just read the IGMP V3 Spec.

V3 is backwards compatible with V2 and V1.

But its the V1 spec that lays down the foundation for Multicast support.

V2 and V3 just add extra features.

Maybe they’re just telling you their device doesn’t do it yet, I.E they’re only partially complaint ?

Cheers

Andy

A&H

16

I think, maybe Wouters question has been misunderstood.

The correct translation of the answer is:

“There are 3 versions of multicast. The needed multicast function is only available in version 3 of IGMP. If you need this function to use t-home entertain, I’m sorry, I have to tell you, that this is not possible.”

I understand this, as if the router supports versions 1 and 2, but not 3.

Greetings from Austria :wink:

Andy

17

To be clear, I never doubted Andy :smiley: It’s TP-LINK’s support that I doubted, and with reason. Now I’ve got another reply from the english support team.

Their answer:

"Dear Wouter,

Thank you very much for your email requesting information about our product. This is Austin from TP-LINK support group.

On the latest firmware of TL-WR1043ND, there is no option for you to turn on or off IGMP multicast, but it supports this feature. Generally, IPTV users requires this feature on the router, if you have IPTV service, then you can check the IGMP multicast by IPTV.

For any further help, please feel free to let me know. To get technical support more quickly, please go to https://www.tp-link.com/en/support/faq.aspx?type=2

Best Regards

Austin Hu

Technical Support Engineer

TP-LINK TECHNOLOGIES CO., LTD."

UPDATE 16/02/2011

And I received another mail that confirms again:

TPLINK TL-WR1043ND router supports IGMP v1 and v2.

So it seems compliant to A&H requirements for multicast.</font id=“red”>

Wouter

My prayers have been heard, Dante is coming!

18

I neither doubted Andy nor Wouter :smiley:

I just wanted to translate the answer from TP-Link more precisely, because from Andy’s post, I got the impression, he did not understand exactly what they meant. My experiences with supports from many different companies let me think, that very often you don’t get an answer that fits to your question.

At the rare occasions, when I needed iLive support, the Austrian distributer’s support was very quick and helpful.

BTW …I just tried an iPad with a very cheap router (multicast disabled), and everything worked perfect :-)Even if I’m no Apple fan, I think I’ll have to buy an iPad and the Mixpad app! The app is worth every € !!!

Andy

19

thanks for your explain of the multicast option, i feel informed better.

my experience with the wireless remoting brought me to the desktop remote of windows.

i connect a stationary laptop with a wireless router together with the mixrack (wired!)

with my tablet i use the desktop remote to remoting the stationary laptop.

that offers control instead of just the remoting.

i can run diffrent programs i need, like itunes, or wavelab…

greetings from hamburg

IDR 48 / T112 / Laptop

20

Well, after some further testing with my iPad 2, and having my laptop connected- the airport extreme is just not going to cut it. During my testing with the rta displayed on the laptop, I encountered many times the frequency meters would freeze while making simple fader adjustments on the iPad. Many times I would also encounter “system busy” messages while selecting different channels with the processing view of the super strip. I have multicast turned off on the rig, and turning it on will actually slow things down further with the router I am using. Changing the multicast rate on the extreme does nothing, and it can get very time consuming rebooting the router after a simple adjustment, just to learn that the last 6 minutes made no difference.

Closing out of mixpad did clear up editor on the laptop, and vice versa, with just mix pad and no editor, made scrolling through channels with no latency.

I did learn that many older wireless routers supported IGMP. It seems many of the top manufacturers considered IGMP belongs on a switch versus a router. I am no real networking expert, but reading many different articles suggest this to be true.

I am certainly challenged looking at specs of many brands here in the states.

Going to try out the Belkin this weekend.

CRJ

Oswego, IL

T112 Surface

iDR48 Mix Rack

Sony F Series laptop

Win 7 500GB HD 8G RAM

Airport Extreme & Express

iPad 2 and Dante soon