[mythtv-users] Need tuner trade-off information with Comcast service

[Gary Buhrmaster]

On Thu, Mar 5, 2015 at 3:56 PM, John Moore (CompuCom Systems Inc)
<v-johmo at microsoft.com> wrote:
....
> My opinion, it was worth it.  Just besure to have a 1Gig switch.

Depends on whether one gets the internal or external model.

> It didn’t like 100M, even trying to use 1 tuner.  The moment I connected to 1gig
> switch, a lot of my problems went away.

Note that both the Ceton and the SiliconDust devices
use UDP.  Packets of any type can get dropped if your
network is "busy" (or "bursty"), but when a UDP packet
from a video source gets dropped you may end up
seeing "pixelation".  Some switches support QoS,
but only the SiliconDust device sets a DSCP value,
so for the Ceton, which does not(*), you want a switch
that not only supports QoS, but setting QoS by port.
That means more enterprise style equipment
(sInce the SD product sets DSCP, the prosumer
switches that simply support QoS (usually for VoIP)
are probably adequate).

Of course, if you use a dedicated point-to-point
network (which also happens with the Ceton PCIe
cards, it is a dedicated internal network) that problem
(mostly) goes away, but many people use their
shared/common network, and may experience video
"glitches".

Gary

(*) I submitted an RFE to Ceton to request that
they add DSCP, and maybe it will happen
eventually (or, to be fair, maybe it already has in
later firmware releases).  But as I do not actually
own a Ceton network tuner (I have chosen
SiliconDust as my vendor), I only know that
problems could be seen under specific test
conditions with network based OCUR devices
without network QoS and heavy network traffic.