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Mr Matt
join:2008-01-29
Eustis, FL

Mr Matt

Member

Best Switch for AT&T Uverse

I am moving to an apartment where AT&T Uverse is available. The Residential Gateway (RG) will be installed in a structured wiring cabinet. I intend to install a separate wireless access point since the RG will be in a shielded location. There is a CAT5E to each of three locations where I want to install a Uverse Set Top Box. I also want to install a computer and printer at each location. I have reviewed a number of forums and learned that in order to prevent IPTV flooding of devices other than the STB connected to the switch, I need a switch that supports IGMP Snooping. Since I will need at least three switches I am looking for affordable switches. I found the TP Link TL-SG108E, a managed switch with basic automatic IGMP Snooping. The manufacture claims that when the IGMP feature is enabled, the switch will direct IPTV streams only to those ports requiring the stream. My main concern is whether I need the capability of more sophisticated switch, like the Netgear GS108Tv2 or TP-Link TL-SG2008 that allows the user to manually set IGMP Snooping on a per port basis. Your advice will be appreciated.
Gardentool
join:2013-01-18
Oklahoma City, OK

Gardentool

Member

Matt, I went looking through a bunch of threads a few weeks ago trying to find information about switches to use in my structured wiring enclosure for the entire network. While I wasn't trying to do exactly what you are doing, my conclusion from the reading was that many of the switches even claiming IGMP Snooping v3 support were not working correctly. I'm not sure I came across one thread were somebody was something they did have something that worked.

Wily_One
Premium Member
join:2002-11-24
San Jose, CA

Wily_One

Premium Member

Does anyone know how U-verse uses IGMP? If it's only for IPTV, it should just be for the DVR/STBs, not the whole LAN. In my case my DVR & STBs are via coax, so I shouldn't need any IGMP at all on the Ethernet side, and could therefore block, right?

OSUGoose
join:2007-12-27
Columbus, OH

OSUGoose to Mr Matt

Member

to Mr Matt
This is what AT&T uses:

»www.att.com/equipment/ac ··· q_model=

alchav
join:2002-05-17
Saint George, UT

alchav to Mr Matt

Member

to Mr Matt
I have FTTH with IPTV, and my Provider installed a Netgear GigaBit Switch in the Structured Wiring Cabinet and connected my HDTV's with Cat5 runs from there. I wanted my own Internal Network, so I put a Linksys Router that runs to a Linksys GigaBit Switch to connect my two Desktops, Server, and Laser Printer. This way I keep my Internal Network separate from my Provider's Network. The IPTV works great, and my Amazon Streaming is amazing on my HDTV.
Mr Matt
join:2008-01-29
Eustis, FL

Mr Matt to Wily_One

Member

to Wily_One
said by Wily_One:

Does anyone know how U-verse uses IGMP?[/bquote

The Residential Gateway uses IGMP snooping to direct IPTV streams to the port a Set Top Box is connected to. As I understand the problem, if an unmanaged switch is connected to a port on the RG and a Uverse Set Top Box is connected to the switch the IPTV stream will be directed to all ports on the switch, causing IPTV flooding to other devices connected to the switch. According to the specification on the TP Link TL-SG108E with IP Snooping turned on, the IPTV stream will be delivered to those ports that have multimedia devices connected to them. My concern is if the TL-SG108E is compatible with the Uverse RG.

Here is an explanation of IGMP snooping from page 78 of the TP Link instruction manual for the TL-SG2008 found here:

»www.tp-link.com/resource ··· 0984.pdf

IGMP Snooping Process:
The switch, running IGMP Snooping, listens to the IGMP messages transmitted between the host and the router, and tracks the IGMP messages and the registered port. When receiving IGMP report message, the switch adds the port to the multicast address table; when the switch listens to IGMP leave message from the host, the router sends the Group-Specific Query message of the port to check if other hosts need this multicast, if yes, the router will receive IGMP report message; if no, the router will receive no response from the hosts and the switch will remove the port from the multicast address table. The router regularly sends IGMP query messages. After receiving the IGMP query messages, the switch will remove the port from the multicast address table if the switch receives no IGMP report message from the host within a period of time.


Wily_One
Premium Member
join:2002-11-24
San Jose, CA

Wily_One

Premium Member

That doesn't answer my question. Does U-verse use IGMP only for IPTV? If so, it should not be broadcast to the Ethernet segment. (if TV is over coax)
DMS1
join:2005-04-06
Plano, TX

DMS1

Member

said by Wily_One:

That doesn't answer my question. Does U-verse use IGMP only for IPTV? If so, it should not be broadcast to the Ethernet segment.

It's not IGMP per-se, but rather the actual multicast traffic that you need to worry about. U-verse uses multicast for TV, having established a multicast group containing the STBs and RG using IGMP. If you have another switch between the RG and one or more STBs that doesn't support IGMP snooping then any other devices attached to that switch will receive all the multicast traffic too, likely causing a significant performance impact.

Wily_One
Premium Member
join:2002-11-24
San Jose, CA

Wily_One

Premium Member

The HomePNA side is coax; my STBs are not using Ethernet so there are no switches involved.

I'll have to check if IGMP traffic is flooding the LAN side.
Mr Matt
join:2008-01-29
Eustis, FL

Mr Matt

Member

said by Wily_One:

I'll have to check if IGMP traffic is flooding the LAN side.

In reality it is the IGMP Snooping feature that keeps IPTV traffic from flooding the LAN if the port the LAN is connected to does not have an STB connected to it. Without a request for multicast traffic by a device connected to a port on the RG the RG will not send multicast traffic to that port. My concern is if the RG uses the same IP address range to transmit IPTV traffic that the Smart Switch uses to detect IPTV traffic.
Mr Matt

Mr Matt to Gardentool

Member

to Gardentool
said by Gardentool:

I went looking through a bunch of threads a few weeks ago trying to find information about switches to use in my structured wiring enclosure for the entire network.

I found this thread related to IGMP Snooping and smart switch configuration in an AT&T Uverse forum here:
»forums.att.com/t5/Setup- ··· 815#M159

brookeKrige
join:2012-11-05
San Jose, CA

brookeKrige to Wily_One

Member

to Wily_One
said by Wily_One:

should not be broadcast to the Ethernet segment. (if TV is over coax)

Don't know but it makes sense. Thinking of coax like a 5th LAN port. RG itself must be as-good-as an IGMP-snooping switch in keeping traffic off its own LAN ports (all LAN interfaces, including coax and wifi) that don't need it.

rolande
Certifiable
MVM,
join:2002-05-24
Dallas, TX
ARRIS BGW210-700
Cisco Meraki MR42

1 recommendation

rolande to Mr Matt

MVM,

to Mr Matt
IGMP snooping is a process whereby a switch identifies which physical switch ports have a host attached that wants to receive specific multicast traffic (i.e. U-verse video stream). When the switch sees an IGMP Join message from a host on a port, it implements a filter rule to forward only the multicast traffic matching the multicast group identified in the IGMP Join message (i.e. U-verse TV channel). If you connect all of the STBs directly to the RG via CAT5, the multicast traffic should only forward to those ports on the RG because the AT&T RG does IGMP snooping itself.

FYI On a side note: I discovered at one point almost 2 years ago that all multicast traffic was flooding on all ports on my older 2Wire 3801 RG. Once I rebooted it, IGMP snooping started working again and it stopped flooding to all ports. So there was supposedly an issue where the IGMP snooping filters could get hosed and the 2Wire would just flood all ports.

Only in the case that you attach an STB to a downstream switch that you have attached to the RG will you really need a switch that can do IGMP snooping. In that case, you would only be flooding the traffic for the particular channel that STB is receiving. If it is the DVR you've attached downstream, it would flood all channels being recorded or that any STB is receiving simultaneously. It would also be transmitting all channels that other STBs are watching back up the uplink connection via multicast. (The DVR manages all local video distribution. I would not recommend attaching it on a downstream switch from the RG if possible.) That could be a considerable amount of traffic. If it is a standalone STB it can only receive one channel at a time. The max amount of traffic would be around 6Mbps for an HD video stream. If all your devices are attached to your network at 100Mbps, it would not be a significant amount of traffic in that case.

In the case of the newer NVG589, the switch ports are capable of 1Gbps speeds. If you need to connect the DVR to a downstream switch you should make sure the uplink is at 1Gbps. This should give you plenty of headroom for your internal network.