[mythtv-users] Intermittent macroblocking on Ceton InfiniTV 6 ETH - Cure(s)?

Gary Buhrmaster gary.buhrmaster at gmail.com
Mon Jan 9 22:20:10 UTC 2017


On Mon, Jan 9, 2017 at 7:40 PM, Peter Bennett <cats22 at comcast.net> wrote:
> ...  I have previously
> requested Comcast to send a firmware update to my cable card, and they
> did that immediately. In order to do that I assume there must be a two
> way signal so that the cable card can be located on the network.



OCUR devices (HDHR, Ceton) are Unidirectional (the U) devices.
All the traffic is one way(*).  STBs can do a number of things,
including one or two way Docsis communications (DSG), or can
use a return path (typically in the <10MHz range) that allows them
to send upstream data while using a one-way OOB or DSG channel.

The CableCARD firmware is often sent in the OOB (low
bitrate, low reliability) multiplex that sends the segments of the
firmware slowly but surely (just like the OOB guide data that
slowly, but surely get downloaded, and the code for the STB,
which slowly, but surely, get downloaded.  And the mix also
contains the CableCARD maps, and/or authorizations, which
are sent....)  This data is sent over and over again (because it
has low reliability), which can take minutes, or even hours to
get all the segments.  Once all the required segments are
received, the code is flashed, the maps are updated, the
authorizations are committed.  There may be multiple
firmwares, or maps, or authorizations for multiple devices/platforms
being sent all the time, and your device listens for a match on
its infromation (this allows the MSO to selectively update
some devices).  If you really want to know the gory details,
the SCTE and CableLabs sites can searched.  The details
of the individual segments are manufacturer and software
release specific (not everyone uses the same guide format
for example).





(*) Since it is one-way, any CSR that says "It looks good to me"
is misunderstanding what they are looking at.  They have nothing
to look at other than that there are host/data/ids in the display.
Only STBs can call home.


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