Motorola DCT2000 - RF Return Path working?

Post by Captain America
I have a question on the RF Return on the Motorola DCT2000
(DCT2244/ABCDEFG) which has both the StarVue II RF Return as well as a
telco return option. I remember before this monday when the network was
rebuilt on Comcast (former AT&T/TCI/Viacom) area, the setup menu
configuration shows the return path as Telco, now it shows up as RF Return
after the new network is launched. However, on the DCT 2000 Diagnostics
STARVUE II DIAGNOSTICS
STATUS : -
FREQUENCY : 11.552Mhz
LEVEL : 25
IPPV : ENABLED
LAST POLL REQ : 48
11-25-2003 07:43:11
LAST POLL ACK : 75
11-27-2003 09:26:11
Am I reading this correctly that the RF Return is working, the way my cable
Wall -> Input A on Mitsubitshi HSU-70 SVHS VCR -> Loop-thru -> Motorola
DCT2000 -> Input B on Mitsubitshi HSU-70 SVHS VCR -> Pioneer PDP4330HD
Plasma TV Media Receiver?

Be careful. It is very rare that a VCR will allow an return RF path. I
suggest splitting the RF input and dedicate one side to the DCT input. Use
A/V patches to loop in the VCR.

It appears form your data that the RF return is functional. What I don't
understand is an update timestamp two days after the last request timestamp.
A typo on your part?

An RF level of 25 is very low suggesting you are connected to a low
attenuation tap with a more or less direct connection to that particular
outlet. There seems to be little return loss to overcome. It's possible
that 11.552mHz is a very clean spot in the sub-band, but I doubt it.
Because return noise is cumulative it is very common to see return levels at
55 dBmV or higher. It's possible, if RF return is a new feature of your
plant, that system balancing has yet to be fully fleshed out.

Post by Captain America
Since is basically the LAST POLL REQ when the
headend last polled the box and LAST POLL ACK is when it last responded?

This is correct. Did you misread the request/acknowledge dates? They
should match, or the acknowledge will lag behind the request date.

Post by Captain America
Also, another question is I noticed the time seems to always be a future
time/date - is it just using the Greenwhich Mean Time (GMT) instead of
Pacific Standard Time GMT -8? Thanks.
John

You don't say what time zone you are in, but GMT is standard operating
procedure.

weithrino

Captain America

2003-12-01 10:48:18 UTC

Post by Captain America
I have a question on the RF Return on the Motorola DCT2000
(DCT2244/ABCDEFG) which has both the StarVue II RF Return as well as
a telco return option. I remember before this monday when the network
was rebuilt on Comcast (former AT&T/TCI/Viacom) area, the setup menu
configuration shows the return path as Telco, now it shows up as RF
Return after the new network is launched. However, on the DCT 2000
STARVUE II DIAGNOSTICS
STATUS : -
FREQUENCY : 11.552Mhz
LEVEL : 25
IPPV : ENABLED
LAST POLL REQ : 48
11-25-2003 07:43:11
LAST POLL ACK : 75
11-27-2003 09:26:11
Am I reading this correctly that the RF Return is working, the way my

cable

Post by Captain America
Wall -> Input A on Mitsubitshi HSU-70 SVHS VCR -> Loop-thru ->
Motorola DCT2000 -> Input B on Mitsubitshi HSU-70 SVHS VCR -> Pioneer
PDP4330HD Plasma TV Media Receiver?

Be careful. It is very rare that a VCR will allow an return RF path.
I suggest splitting the RF input and dedicate one side to the DCT
input. Use A/V patches to loop in the VCR.

Yeah but you never know since this VCR seems to send the full signal from
input A to the loop-thru from what I can tell.

Post by weitrhino
It appears form your data that the RF return is functional. What I
don't understand is an update timestamp two days after the last
request timestamp. A typo on your part?

What does the each line mean though?

STATUS : -
IPPV : ENABLED
LAST POLL REQ : 48
11-25-2003 07:43:11
LAST POLL ACK : 75
11-27-2003 09:26:11

The IPPV is Interactive Pay Per View right? But what exactly is the Status
and how do you interpret it since it's just a -. So Poll Req is when the
headend last polled the box and what's the acknowledgement? Is it just the
upstream packet that was sent but does it only update when it's successful
or does it say something else if the packet never made it to the other
side. As for the Poll Req timestamp, that was when it was switched to the
new rebuilt system on Monday, November 24, 2003 which was probably already
which was sometime in the AM San Francisco time which is GMT -800 so it was
a later poll. The Acknowledgement timestamp seems to be 11-29-2003 when I
checked sometime Friday night so maybe they are just testing the headend or
something. I was wondering what the 48 and 75 means?

Post by weitrhino
An RF level of 25 is very low suggesting you are connected to a low
attenuation tap with a more or less direct connection to that
particular outlet. There seems to be little return loss to overcome.
It's possible that 11.552mHz is a very clean spot in the sub-band, but
I doubt it. Because return noise is cumulative it is very common to
see return levels at 55 dBmV or higher. It's possible, if RF return
is a new feature of your plant, that system balancing has yet to be
fully fleshed out.

It's not really a tap. From what I gather, I live in a big apartment
building with 60 apartments and there is a cable that is like the size of
three RG-6QS cables that runs to the roof, maybe it's fiber optic cable as
it only existed about 2 weeks ago to connect the building to the new
network. The cable runs into a amplifier on the roof and then it goes
through 8 way 1Ghz splitters where one outlet goes to each apartment.
Ofcourse, after it ends in my apartment, I have a 4 way 5Mhz-2Ghz splitter
where one goes to the Plasma direct, the other goes through the VCR and
then DCT2000 and the third one goes to my computers tuner. I don't have
the 4th one hooked up yet so could that be the reason because I am running
it through a splitter. The RF Return seems to be new as our neighborhood
just got connected a week ago as they rebuild the entire city at the same
time. So 25 is really 25 dBmV?

Post by Captain America
Since is basically the LAST POLL REQ when the
headend last polled the box and LAST POLL ACK is when it last
responded?

This is correct. Did you misread the request/acknowledge dates? They
should match, or the acknowledge will lag behind the request date.

Nope, it's correct. The last one shows 11-29-2003 when I checked it Friday
night/Saturday morning.

Post by Captain America
Also, another question is I noticed the time seems to always be a
future time/date - is it just using the Greenwhich Mean Time (GMT)
instead of Pacific Standard Time GMT -8? Thanks.
John

You don't say what time zone you are in, but GMT is standard operating
procedure.

Actually, I did. Pacific Standard Time is PST and basically 8 hours behind
GMT as I'm in San Francisco, California. This is the latest one as of this
minute:

STARVUE II DIAGNOSTICS

STATUS : -
FREQUENCY : 11.552Mhz
LEVEL : 25
IPPV : ENABLED

LAST POLL REQ : 48
11-25-2003 07:43:11
LAST POLL ACK : 92
11-27-2003 09:27:34

It seems the ack's timestamp is updated every two days but isn't the REQ
supposed to update as well?

Post by weitrhino
weithrino

Thanks,
John

weitrhino

2003-12-01 17:26:08 UTC

Post by Captain America
What does the each line mean though?
STATUS : -
IPPV : ENABLED
LAST POLL REQ : 48
11-25-2003 07:43:11
LAST POLL ACK : 75
11-27-2003 09:26:11
The IPPV is Interactive Pay Per View right? But what exactly is the Status
and how do you interpret it since it's just a -. So Poll Req is when the
headend last polled the box and what's the acknowledgement? Is it just the
upstream packet that was sent but does it only update when it's successful
or does it say something else if the packet never made it to the other
side. As for the Poll Req timestamp, that was when it was switched to the
new rebuilt system on Monday, November 24, 2003 which was probably already
which was sometime in the AM San Francisco time which is GMT -800 so it was
a later poll. The Acknowledgement timestamp seems to be 11-29-2003 when I
checked sometime Friday night so maybe they are just testing the headend or
something. I was wondering what the 48 and 75 means?

I'll tell you as much as I am certain. Ippv is Impulse Pay Per View, you
should need nothing more than your remote for ordering PPV. The STATUS
field is correct with a -. My assumption is there would be an error code if
there were an error. There will be no change in the LAST POLL ACK field if
the return packet is unsucessful. The REQ field will change anytime the box
receives a polling request, or a simple refresh box hit. The ACK field will
only change when the return packet is verified by the box controller. As
for the 48 and 75, I am uncertain.

You can call your customer service line and ask them to hit your box and
then watch the box update to see this process in action. If this system has
only just come online, give them some time to get it fully operational. A
fully functioning return RF path via digital boxes is a precursor to cable
modems. I suspect they'll be less than a year away.

weithrino

Post by Captain America
Since is basically the LAST POLL REQ when the
headend last polled the box and LAST POLL ACK is when it last responded?

This is correct. Did you misread the request/acknowledge dates? They
should match, or the acknowledge will lag behind the request date.

Nope, it's correct. The last one shows 11-29-2003 when I checked it Friday
night/Saturday morning.

Post by Captain America
Also, another question is I noticed the time seems to always be a
future time/date - is it just using the Greenwhich Mean Time (GMT)
instead of Pacific Standard Time GMT -8? Thanks.
John

You don't say what time zone you are in, but GMT is standard operating
procedure.

Actually, I did. Pacific Standard Time is PST and basically 8 hours behind
GMT as I'm in San Francisco, California. This is the latest one as of this
STARVUE II DIAGNOSTICS
STATUS : -
FREQUENCY : 11.552Mhz
LEVEL : 25
IPPV : ENABLED
LAST POLL REQ : 48
11-25-2003 07:43:11
LAST POLL ACK : 92
11-27-2003 09:27:34
It seems the ack's timestamp is updated every two days but isn't the REQ
supposed to update as well?

Post by weitrhino
weithrino

Thanks,
John

Captain America

2003-12-01 20:57:19 UTC

Status

Post by Captain America
and how do you interpret it since it's just a -. So Poll Req is when
the headend last polled the box and what's the acknowledgement? Is
it just

the

Post by Captain America
upstream packet that was sent but does it only update when it's
successful or does it say something else if the packet never made it
to the other side. As for the Poll Req timestamp, that was when it
was switched to the new rebuilt system on Monday, November 24, 2003
which was probably already which was sometime in the AM San Francisco
time which is GMT -800 so it

was

Post by Captain America
a later poll. The Acknowledgement timestamp seems to be 11-29-2003
when I checked sometime Friday night so maybe they are just testing
the headend

Post by Captain America
something. I was wondering what the 48 and 75 means?

I thought the - would be a bad thing since it's kind of like a uncertain
status or something. The thing I'm confused about is the ACK field which
seems to update around 1am every two days. Wouldn't a new REQ have to be
sent before it will do a ACK or is it just the REQ can specify the time
interval that the box needs to send a return packet, something like telling
the box to send data back every 48 hours? I wonder if the 48 and 75 is the
sequence number or just the signal level?

Post by Captain America
You can call your customer service line and ask them to hit your box
and then watch the box update to see this process in action. If this
system has only just come online, give them some time to get it fully
operational. A fully functioning return RF path via digital boxes is
a precursor to cable modems. I suspect they'll be less than a year
away.

The cable modem became available on the same day the new system was
launched since Comcast I think is trying to get their new networks rolling
as there is a 20% in pricing for standard cable in the new network versus
old network areas. I don't think the network is completely rebuilt yet as
the streets seems to have all these markings on the ground and lots of the
pothole covers have not been replaced as of yet which seems to be something
they do once they are finished with that area. People who are one block
away from me had the new network launched back on October 2 but they seem
to have worst signal quality on channels 54-70. What seemed to have
happened was that we were on the old network and then they rebuilt the
network but the building somehow lost the signal for a week before the new
network got wired so they had to do some temporary fix to get the signal to
the building before they finally wired the building to the new network
which took an entire day about 2 weeks ago.

Post by Captain America
weithrino

Thanks,
John

Post by weitrhino
An RF level of 25 is very low suggesting you are connected to a low
attenuation tap with a more or less direct connection to that
particular outlet. There seems to be little return loss to
overcome. It's possible that 11.552mHz is a very clean spot in the
sub-band, but I doubt it. Because return noise is cumulative it is
very common to see return levels at 55 dBmV or higher. It's
possible, if RF return is a new feature of your plant, that system
balancing has yet to be fully fleshed out.

It's not really a tap. From what I gather, I live in a big apartment
building with 60 apartments and there is a cable that is like the
size of three RG-6QS cables that runs to the roof, maybe it's fiber
optic cable as it only existed about 2 weeks ago to connect the
building to the new network. The cable runs into a amplifier on the
roof and then it goes through 8 way 1Ghz splitters where one outlet
goes to each apartment. Ofcourse, after it ends in my apartment, I
have a 4 way 5Mhz-2Ghz splitter where one goes to the Plasma direct,
the other goes through the VCR and then DCT2000 and the third one
goes to my computers tuner. I don't have the 4th one hooked up yet
so could that be the reason because I am running it through a
splitter. The RF Return seems to be new as our neighborhood just got
connected a week ago as they rebuild the entire city at the same
time. So 25 is really 25 dBmV?

Post by Captain America
Since is basically the LAST POLL REQ when the
headend last polled the box and LAST POLL ACK is when it last responded?

This is correct. Did you misread the request/acknowledge dates?
They should match, or the acknowledge will lag behind the request
date.

Nope, it's correct. The last one shows 11-29-2003 when I checked it

Friday

Post by Captain America
night/Saturday morning.

Post by Captain America
Also, another question is I noticed the time seems to always be a
future time/date - is it just using the Greenwhich Mean Time (GMT)
instead of Pacific Standard Time GMT -8? Thanks.
John

You don't say what time zone you are in, but GMT is standard
operating procedure.

Actually, I did. Pacific Standard Time is PST and basically 8 hours

behind

Post by Captain America
GMT as I'm in San Francisco, California. This is the latest one as
of

this

Post by Captain America
STARVUE II DIAGNOSTICS
STATUS : -
FREQUENCY : 11.552Mhz
LEVEL : 25
IPPV : ENABLED
LAST POLL REQ : 48
11-25-2003 07:43:11
LAST POLL ACK : 92
11-27-2003 09:27:34
It seems the ack's timestamp is updated every two days but isn't the
REQ supposed to update as well?

Post by weitrhino
weithrino

Thanks,
John

Captain America

2003-12-01 21:20:33 UTC

Status

Post by Captain America
and how do you interpret it since it's just a -. So Poll Req is when
the headend last polled the box and what's the acknowledgement? Is
it just

the

was

Post by Captain America
a later poll. The Acknowledgement timestamp seems to be 11-29-2003
when I checked sometime Friday night so maybe they are just testing
the headend

Post by Captain America
something. I was wondering what the 48 and 75 means?

I'll tell you as much as I am certain. Ippv is Impulse Pay Per View,
you should need nothing more than your remote for ordering PPV. The
STATUS field is correct with a -. My assumption is there would be an
error code if there were an error. There will be no change in the
LAST POLL ACK field if the return packet is unsucessful. The REQ
field will change anytime the box receives a polling request, or a
simple refresh box hit. The ACK field will only change when the
return packet is verified by the box controller. As for the 48 and
75, I am uncertain.
You can call your customer service line and ask them to hit your box
and then watch the box update to see this process in action. If this
system has only just come online, give them some time to get it fully
operational. A fully functioning return RF path via digital boxes is
a precursor to cable modems. I suspect they'll be less than a year
away.
weithrino

Just a update... I called Comcast and did the automated reauthorization to
the box and this is what I noticed as the final result...

STARVUE II DIAGNOSTICS

STATUS : -
FREQUENCY : 11.552Mhz
LEVEL : 25
IPPV : ENABLED

LAST POLL REQ : 112
12-01-2003 21:05:25
LAST POLL ACK : 112
12-01-2003 21:06:45

The FREQUENCY started at 11.552Mhz and then it changed to 8.096Mhz while
the Level went from 25 38 24 40 48 56 41 49 57 and then back to 25. Both
the REQ and ACK started at 108 so I think that's the sequence number. When
the FREQUENCY and LEVEL changed, the REQ went up one at a time to 109, 110,
111, 112 while the ACK still stayed at 108 and didn't change until the REQ
made it to 112 so it seems like the sequence number where it's the 112th
REQ and 112th ACK. I just hope there won't be any issues when the DCT5100
replaces this box next week.

Thanks,
John

itv_guy

2003-12-02 01:28:56 UTC

Status

Post by Captain America
and how do you interpret it since it's just a -. So Poll Req is when
the headend last polled the box and what's the acknowledgement? Is
it just

the

was

Post by Captain America
a later poll. The Acknowledgement timestamp seems to be 11-29-2003
when I checked sometime Friday night so maybe they are just testing
the headend

Post by Captain America
something. I was wondering what the 48 and 75 means?

I'll tell you as much as I am certain. Ippv is Impulse Pay Per View,
you should need nothing more than your remote for ordering PPV. The
STATUS field is correct with a -. My assumption is there would be an
error code if there were an error. There will be no change in the
LAST POLL ACK field if the return packet is unsucessful. The REQ
field will change anytime the box receives a polling request, or a
simple refresh box hit. The ACK field will only change when the
return packet is verified by the box controller. As for the 48 and
75, I am uncertain.
You can call your customer service line and ask them to hit your box
and then watch the box update to see this process in action. If this
system has only just come online, give them some time to get it fully
operational. A fully functioning return RF path via digital boxes is
a precursor to cable modems. I suspect they'll be less than a year
away.
weithrino

When

Post by Captain America
the FREQUENCY and LEVEL changed, the REQ went up one at a time to 109, 110,
111, 112 while the ACK still stayed at 108 and didn't change until the REQ
made it to 112 so it seems like the sequence number where it's the 112th
REQ and 112th ACK. I just hope there won't be any issues when the DCT5100
replaces this box next week.
Thanks,
John

The LAST POLL REQ field contains the sequence number of the last poll
request received by the DCT2000. The time stamp of the last poll request
will be displayed immediately below LAST POLL REQ. If no poll request has
been received by the DCT2000, the sequence number field will display N/A and
the time stamp field will display N/A. If a poll request has been received
by the DCT2000 but the system time of the DCT2000 has not yet been
initialized, the time stamp field will display NOT AVAILABLE.

The LAST POLL ACK field contains the sequence number of the last poll
acknowledge received by the DCT2000. The time stamp of the last poll
acknowledge will be displayed immediately below LAST POLL ACK. If no poll
acknowledge has been received by the DCT2000, the sequence number field will
display N/A and the time stamp field will display N/A. If a poll acknowledge
has been received by the DCT2000 but the system time of the DCT2000 has not
yet been initialized, the time stamp field will display NOT AVAILABLE.

Captain America

2003-12-02 19:24:17 UTC

Post by itv_guy

Status

Post by Captain America
and how do you interpret it since it's just a -. So Poll Req is
when the headend last polled the box and what's the
acknowledgement? Is it just

the

Post by Captain America
upstream packet that was sent but does it only update when it's
successful or does it say something else if the packet never made
it to the other side. As for the Poll Req timestamp, that was
when it was switched to the new rebuilt system on Monday, November
24, 2003 which was probably already which was sometime in the AM
San Francisco time which is GMT -800 so it

was

Post by Captain America
a later poll. The Acknowledgement timestamp seems to be
11-29-2003 when I checked sometime Friday night so maybe they are
just testing the headend

Post by Captain America
something. I was wondering what the 48 and 75 means?

I'll tell you as much as I am certain. Ippv is Impulse Pay Per
View, you should need nothing more than your remote for ordering
PPV. The STATUS field is correct with a -. My assumption is there
would be an error code if there were an error. There will be no
change in the LAST POLL ACK field if the return packet is
unsucessful. The REQ field will change anytime the box receives a
polling request, or a simple refresh box hit. The ACK field will
only change when the return packet is verified by the box
controller. As for the 48 and 75, I am uncertain.
You can call your customer service line and ask them to hit your
box and then watch the box update to see this process in action.
If this system has only just come online, give them some time to
get it fully operational. A fully functioning return RF path via
digital boxes is a precursor to cable modems. I suspect they'll be
less than a year away.
weithrino

When

Post by Captain America
the FREQUENCY and LEVEL changed, the REQ went up one at a time to
109,

110,

Post by Captain America
111, 112 while the ACK still stayed at 108 and didn't change until
the REQ made it to 112 so it seems like the sequence number where
it's the 112th REQ and 112th ACK. I just hope there won't be any
issues when the DCT5100 replaces this box next week.
Thanks,
John

The LAST POLL REQ field contains the sequence number of the last poll
request received by the DCT2000. The time stamp of the last poll
request will be displayed immediately below LAST POLL REQ. If no poll
request has been received by the DCT2000, the sequence number field
will display N/A and the time stamp field will display N/A. If a poll
request has been received by the DCT2000 but the system time of the
DCT2000 has not yet been initialized, the time stamp field will
display NOT AVAILABLE.
The LAST POLL ACK field contains the sequence number of the last poll
acknowledge received by the DCT2000. The time stamp of the last poll
acknowledge will be displayed immediately below LAST POLL ACK. If no
poll acknowledge has been received by the DCT2000, the sequence number
field will display N/A and the time stamp field will display N/A. If a
poll acknowledge has been received by the DCT2000 but the system time
of the DCT2000 has not yet been initialized, the time stamp field will
display NOT AVAILABLE.

Thanks for the explanation. Okay, I guess the other question I have is the
LAST POLL ACK timestamp and sequence updates every 2 days but the LAST POLL
REQ remains the same with no updated timestamp. Doesn't a ACK require a
new POLL REQ each time or does the LAST POLL REQ simply contain information
on the time interval it needs to send ACK's back? And does LAST POLL ACK
only mean the box send a signal back without confirming whether the other
end received it or not or is it basically telling you when the last time
the other side confirmed the ACK packet?

Thanks,
John

weitrhino

2003-12-06 04:29:28 UTC

---- Original Message -----
From: "Captain America" <***@America.org.invalid>
Newsgroups: alt.cable-tv,alt.cable-tv.tci-digital,rec.video.cable-tv
Sent: Monday, December 01, 2003 4:20 PM
Subject: Re: Motorola DCT2000 - RF Return Path working?

Post by Captain America
I just hope there won't be any issues when the DCT5100
replaces this box next week.
Thanks,
John

I will respectfully bow out at this point because my experience with the
back-end operation of the box controller is limited. I can tell you the
DCT5100 will have different dignostic screens.

weithrino

Captain America

2003-12-06 21:19:10 UTC

Post by weitrhino
---- Original Message -----
Newsgroups: alt.cable-tv,alt.cable-tv.tci-digital,rec.video.cable-tv
Sent: Monday, December 01, 2003 4:20 PM
Subject: Re: Motorola DCT2000 - RF Return Path working?

Post by Captain America
I just hope there won't be any issues when the DCT5100
replaces this box next week.
Thanks,
John

The DCT5100 does have different diagnostic screens. What I was trying to
find out from the DCT2000 was that the RF Return Path was indeed working.
The only part I'm confused is the LAST POLL REQ timestamp doesn't update
while the LAST POLL ACK does update every 2 days. Does the LAST POLL REQ
simply tell it to send ACK packets at 48 hour intervals and does the ACK
timestamp only update when the head controller acknowledges the packet the
box sent or does it simply update the timestamp even if the packet was sent
but isn't confirmed by the other side.

Thanks,
John

weitrhino

2003-12-07 03:49:14 UTC

Post by Captain America
I just hope there won't be any issues when the DCT5100
replaces this box next week.
Thanks,
John

This may be a configurable system parameter. In my system, an
acknowledgement only appears as a result of a request. But I suppose it is
possible for a controller to be configured to embed an upload command to
function at regular intervals. That would seem to make sorting the return
data of thousands of boxes a difficult task unless the upload is keyed by
the system timestamp and the controller expects certain boxes to respond at
a given timestamp.

But I'm out of the know and only guessing here.

weitrhino

Captain America

2003-12-07 05:09:20 UTC