Tanix Tx3 as TV backend server

Talisman

Johnboy1951 wrote: »

You can report what you needed to do to get the IGMP snooping working on that.

The FAQ makes it seem quite trivial to setup - How to configure IGMP Snooping for IPTV network using L2 switch.

I'll report my findings when the task is complete.

Talisman

IGMP snooping requires a multicast router in the network otherwise the multicast traffic floods everywhere - this is the key lesson learned this week.

A Cisco engineer told me that the router is responsible for the multicast groups. The role of the network switch is to listen in to the IGMP traffic between the hosts and the router. The switch keeps a record of which hosts are members of the group so it knows where to direct the multicast traffic. Without the snooping of multicast group membership the switch will treat all multicast traffic like broadcast traffic.

I have an old Draytek firewall gathering dust in the attic and I remember seeing the IGMP settings in the web interface years ago so I'll nurse it back to life to try it out but it seems like overkill for a simple home network.

Johnboy1951

Talisman wrote: »

IGMP snooping requires a multicast router in the network otherwise the multicast traffic floods everywhere - this is the key lesson learned this week.

A Cisco engineer told me that the router is responsible for the multicast groups. The role of the network switch is to listen in to the IGMP traffic between the hosts and the router. The switch keeps a record of which hosts are members of the group so it knows where to direct the multicast traffic. Without the snooping of multicast group membership the switch will treat all multicast traffic like broadcast traffic.

I have an old Draytek firewall gathering dust in the attic and I remember seeing the IGMP settings in the web interface years ago so I'll nurse it back to life to try it out but it seems like overkill for a simple home network.

I am unsure of the import of the above ...... does it mean that not only is a compatible switch required (a lot of devices) but also the main router/switch needs to be compatible also?

I had expected that multicast traffic in to a switch got directly routed to the group membership hanging off the switch without ever reaching back to the router/switch ...... maybe that is what caught me ........

.... ?

Talisman

The Draytek was a headache - it has IGMP but it can't be used if the device is in bridge mode and also doesn't work if the WAN port isn't connected so it's back in the attic!

I've been reading RFC 3376 - Internet Group Management Protocol, Version 3, it's the document which describes the protocol and as you can imagine is quite the page turner. The good news is that IGMP is implemented in software so there is no special hardware requirement.

I found the Scapy project which is implemented in Python, the code library contains a class for IGMP v3. My intention is to create a script to run as a service on the RPi which will implement the router/querier functionality.

Talisman

Johnboy1951 wrote: »

I am unsure of the import of the above ...... does it mean that not only is a compatible switch required (a lot of devices) but also the main router/switch needs to be compatible also?

I had expected that multicast traffic in to a switch got directly routed to the group membership hanging off the switch without ever reaching back to the router/switch ...... maybe that is what caught me ........

.... ?

The cheap home network routers like the ones that we get from service providers do not provide an IGMP querier. The job of the querier is to send an IGMP query packet to the multicast broadcast address every minute or so. The role of the network switch is to forward the query packets to all of their ports. When a device connected to the switch receives a query packet it responds by sending requests to join all groups that it wants to belong to.

The IGMP querier is the piece you were missing but as I have learned it doesn't have to be implemented in the router.

Ste-

Johnboy,

Finally bit the bullet on the hdhomerun, what kind of aerial are you feeding into it ? My rabbit ears work fine for the 547 mux but won't tune to 570 at all. Have tried different aerials. Maybe it's the position of them ?

Johnboy1951

Ste- wrote: »

Johnboy,

Finally bit the bullet on the hdhomerun, what kind of aerial are you feeding into it ? My rabbit ears work fine for the 547 mux but won't tune to 570 at all. Have tried different aerials. Maybe it's the position of them ?

I have an outdoor aerial, but am quite a distance from the transmitter.

Have you done a full scan in the HDHomerun web interface?

Ste-

Johnboy1951 wrote: »

I have an outdoor aerial, but am quite a distance from the transmitter.

Have you done a full scan in the HDHomerun web interface?

Yeah a couple of times. I think it's the placement of the aerial. I had it upstairs but it kept crashing my powerline adapters. I connected it straight to the router and that's fine but the reception isn't good enough.

Johnboy1951

Ste- wrote: »

Yeah a couple of times. I think it's the placement of the aerial. I had it upstairs but it kept crashing my powerline adapters. I connected it straight to the router and that's fine but the reception isn't good enough.

Most likely then.

Ste-

Johnboy1951 wrote: »

Most likely then.

Moved it back upstairs. it's no longer crashing my network but it still drops to 0 occasionly on the SNR causing data errors in tvheadend.

Johnboy1951

Maybe you could consider an 'outdoor' aerial, even fitted in the attic if outside is too problematic, should be a big improvement?

Ste-

Johnboy1951 wrote: »

Maybe you could consider an 'outdoor' aerial, even fitted in the attic if outside is too problematic, should be a big improvement?

Was afraid of that. The same aerials work fine with USB DVB-T inputs tho.

Johnboy1951

It is possible that the problem is not a weak signal/inefficient tuner, but some problem with the HDHomerun.

The only suggestion I would have is to test it in another location to see if it works correctly ... thus using a different aerial.

Maybe a post in the Terrestrial section would get some helpful responses?

Ste-

Johnboy1951 wrote: »

It is possible that the problem is not a weak signal/inefficient tuner, but some problem with the HDHomerun.

The only suggestion I would have is to test it in another location to see if it works correctly ... thus using a different aerial.

Maybe a post in the Terrestrial section would get some helpful responses?

Have tried it in different rooms, upstairs downstairs all with the same issue. I might have to get on to silicondust support get them to check it.

Johnboy1951

Ste- wrote: »

Have tried it in different rooms, upstairs downstairs all with the same issue. I might have to get on to silicondust support get them to check it.

The different location I had in mind was not within your house but elsewhere, so a different aerial and reception conditions would be tested.

Ste-

Johnboy1951 wrote: »

The different location I had in mind was not within your house but elsewhere, so a different aerial and reception conditions would be tested.

I've moved the aerial away from most of the electrics and the data errors have dropped to an average of 1000/1500 wheres before it ws failing recordings because there was so many data errors.

Johnboy1951

IMO you really need to use a proper aerial and not just some 'rabbit ears'.