[mythtv-users] trouble with CSPAN channels

Gary Buhrmaster gary.buhrmaster at gmail.com
Sat Mar 6 17:41:14 UTC 2021

On Sat, Mar 6, 2021 at 3:38 PM Greg Woods <greg at gregandeva.net> wrote:

> Thanks for any advice,

You are almost certainly experiencing the Comcast
IPTV migration.

In a number (I think most at this point) of franchises
the CSPAN channels (specifically the HD variants)
were converted to IPTV (only).  The SD version is still
available in linear QAM (which your CableCARD can
still tune) due to the need to be able to support the
(original) DTAs still in customer locations(***).  So in
order to access CSPAN (the SD version) you will
need to look at your local channel lineup, and change
to using that.  Same for CSPAN2 and CSPAN3.

As background, Comcast has a plan to migrate to
IPTV from linear QAM to free up bandwidth for
HSI.  Newly added channels are typically added
only in IPTV(*).  Existing HD channels with low(er)
viewership are also being selected to be moved
to IPTV only.  This has been ongoing for well
over a year now, and is shown on your bill(**).
In order to access those new channels, or to
continue to access the channels migrated, one
needs to use one of their boxes (or use their
streaming app).

If you go to your local Comcast store you can get
a channel lineup card which includes (in with some
small asterisk) which channels are IPTV.  The
online channel lineup (available at
   https://www.xfinity.com/support/local-channel-lineup )
does not (or did not) have that information.

Unfortunately, this migration has broken the
implied intent of the MCLU channels (1129
in your case) where a MCLU channel would get
the "best available" (whether that is HD or SD)
version of the channel.  For those channels
migrated to IPTV the linear QAM channel
map for CableCARDs does not fall back to
the SD version (the "best available") it just
does not work at all (of course if you are
using the X1 box it works as expected).

And for planning purposes, while Comcast has
not shared their schedules, it is clear that over
the long term CableCARDs will be able to receive
fewer and fewer channels, and you will need to
plan to either move to one of Comcast's X1 boxes
(if you want Comcast TV), migrate to another
TV provider, or just drop TV content.

As one would expect, the TiVo crowd (the largest
number of CableCARD users (which is not saying
much, the FCC numbers suggest OCUR/UDCP
users are a very small number total)) have been
up in arms over this, but most of the rational
ones have moved to the final stage of acceptance,
and either have moved on, or will continue using
their TiVo until such time a channel they care
about is migrated.

Good luck.

(*) Note, this being Comcast, there are
exceptions to every plan, and in particular
newly added channels that have an extremely
high local demand may be placed into linear
QAM in that location only to preserve the
available bandwidth (the last example was
the Marquee network which is in linear QAM
in the local Chicago area, but a previous
example is the Pac-12 network which is
IPTV in many markets, but linear QAM in
the markets where the member teams are

(**) If you read the small small print on your
bill (the part you likely never read, but you
perhaps should) it will talk about a channel
being added or migrated often using terms
such as "compatible equipment required"
(which means X1 or streaming app), or, in
some more recent bills, calling out HD IP or
IPTV explicitly.  In the case of CSPAN you
might need to go back to your historical
bills for quite a ways back.

(***) In addition to the DTAs, there is some
other existing equipment in the field, but
Comcast already has equivalent equipment
(at a very low BoM cost) that they can
easily deploy whenever they choose to
pull the trigger to do a wholesale replacement.

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