[mythtvnz] Kernel updates with TBS tuners -> HDHomeRun

[Stephen Worthington]

On Thu, 1 Nov 2018 21:29:01 +1300, you wrote:

>Greetings all
>
>I'm tired of hoops I seem to have to jump through when I do a kernel
>update on my backend machine to accommodate the TBS6281 (DVB-T) and
>TBS6982 (DVB-S) tuners I have.
>
>The DVB-S tuner is redundant now so I'm looking to simplify the whole
>setup with a SiliconDust HDHomeRun Connect Quatro for DVB-T only that can
>sit next to the aerial feed and main Ethernet switch in the garage.
>
>How do people who use them rate them? Do they need a huge amount of signal
>to split 4 ways or is it handled more intelligently than that?
>
>I assume 100Mb Ethernet would do but 1Gb would be better - any opinions on
>the optimum setup?
>
>Cheers

From the specifications:

https://www.silicondust.com/product/hdhomerun-quatro/

"100baseTX high-speed network"

So it only has 100 Mbit/s Ethernet.  So with four tuners, each
recording multiple HD channels at once, you would be using a
significant percentage of the 100 Mbit/s bandwidth.  So I would want
to have each Quatro on its own Ethernet card, if I was directly
connecting them to a card.  Going through a gigabit switch to a
gigabit card on the PC, the switch will store the incoming 100 Mbit/s
packets and send them out at 1000 Mbit/s, so you could handle more
than one Quatro on a gigabit card that way.  But even then, I have
heard that the data is sent as UDP packets with no way of
re-transmitting one that is missing or damaged.  So I would not want
to have my Quatro tuners on the same Ethernet card as general traffic,
as general traffic can suddenly be using all the available bandwidth
(eg copying a large file) and cause problems for the tuner traffic. So
my recommended setup would be a separate Ethernet card for the Quatro
tuners, and use a separate subnet for them - either partition the
ports on your switch, if it can do that, or use a separate switch. And
make sure that only the Quatro traffic goes on that subnet - do not
permit SAMBA to use it, for example.

I do wish that SiliconDust would get over using 100 Mbit/s Ethernet
and catch up with the modern world.  Surely they can find a cheap 1000
Mbit/s Ethernet chip to use now.  This is one of the reasons I have
never bought a SiliconDust device.  And they could use a better
protocol that had error recovery.

The other major problem to watch out for is that their wall-wart power
supplies always fail with age, and they also cause strange problems as
they start failing, so it can take ages to work out what the problem
is.  If I was ever to buy a SiliconDust device, I would consider
replacing the power supply immediately with a known good one.