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arcimedes
17-04-2011, 11:29
Since yesterday afternoon the superhub has kept changing from using 4 downstream channels to 1 channel. This does not affect the speeds which are 30Mb whether one channel or four is used or not.

Here is part of the event log

Time Priority Description
Sun Apr 17 08:30:21 2011 Critical (3) DHCP FAILED - Requested Info not supported.;CM-MAC=a0;CMTS-MAC=CM-QOS=1.1;CM-VER=3.0;
Sun Apr 17 08:30:09 2011 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.0;
Sun Apr 17 08:07:59 2011 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=a0;CMTS-MAC=;CM-QOS=1.0;CM-VER=3.0;
Sun Apr 17 08:07:37 2011 Notice (6) CMTS DCC 434250000 MHz
Sun Apr 17 08:06:46 2011 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.0;
Sun Apr 17 07:32:36 2011 Notice (6) CMTS DCC 442250000 MHz
Sun Apr 17 07:10:14 2011 Notice (6) CMTS DCC 0 MHz
Sun Apr 17 06:03:41 2011 Critical (3) DCC aborted unable to communicate on new upstream channel;CM-MAC=a0;CMTS-MAC=;CM-QOS=1.0;CM-VER=3.0;
Sun Apr 17 06:03:41 2011 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:;CMTS-MAC=;CM-QOS=1.0;CM-VER=3.0;
Sun Apr 17 06:02:38 2011 Notice (6) CMTS DCC 450250000 MHz
Sun Apr 17 04:54:37 2011 Critical (3) SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=a0;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.0;
Sun Apr 17 04:49:48 2011 Error (4) DCC rejected parameter invalid for context;CM-MAC=;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

Downstream power

Locked QAM64 169 41712000 Kbits/sec 434250000 Hz 0.4 dBmV 33.9 dB Hybrid
Locked QAM64 170 41712000 Kbits/sec 442250000 Hz 1.3 dBmV 34.5 dB Hybrid
Locked QAM64 171 41712000 Kbits/sec 450250000 Hz 0.9 dBmV 34.2 dB Hybrid
Locked QAM64 172 41712000 Kbits/sec 458250000 Hz 1.2 dBmV 34.5 dB Hybrid

Upstream power

Locked ATDMA 2 20480 Kbits/sec 35800000 Hz 58.2 dBmV

The only thing I did yesterday was cut away the vegetation around the outside box in preparation for tivo installation. I dont think that would have had any effect:)

I think when its one one downstream channel the power goes to about 40 but of courses while I've been typing this it hasnt switched over to one channel

---------- Post added at 10:29 ---------- Previous post was at 09:41 ----------

Just got power levels when locked on 1 channel only.

I did find the cable outside was a bit loose so have tightened it up.

We will se if that makes any difference.




Downstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power SNR Docsis/EuroDocsis locked
Locked QAM64 171 41712000 Kbits/sec 450250000 Hz 38.1 dBmV 33.5 dB Hybrid
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown


--------------------------------------------------------------------------------

Upstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power
Locked ATDMA 2 20480 Kbits/sec 35800000 Hz 56.7 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV

Ignitionnet
17-04-2011, 11:32
Upstream power too high, downstream power ridiculously high and SNR poor. I'm amazed you have one channel locked.

Either your superhub is hosed or there's an area fault. Check the service status and if no fault present get a tech visit.

Chrysalis
17-04-2011, 12:00
the fact you had a single 42mbit channel give you full speeds suggests your area is very low utilised.

When I was down to a single channel I was able to only achieve around 20-25mbit on speedtests, and mine is QAM256 vs your QAM64. So in my area if they rolled this out on docsis1 tech I would be having performance issues.

jb66
17-04-2011, 12:46
I didnt think it was possible to have a downstream that high, my meter cant go that high! Something is really wrong!

Peter_
17-04-2011, 12:48
I didnt think it was possible to have a downstream that high, my meter cant go that high!
Seen them in the mid twenties on our tools maybe the Superhub can show higher levels.

jb66
17-04-2011, 12:50
yeah probably, over 20 and it says "level too high"

pip08456
17-04-2011, 12:52
Seen them in the mid twenties on our tools maybe the Superhub can show higher levels.

Seems like the superhub can do multiple things except work correctly!:D

Peter_
17-04-2011, 12:52
yeah probably, over 20 and it says "level too high"
I have seen 29 but no higher as usually it is offline, surprised he had a connection that high.

arcimedes
17-04-2011, 12:59
Seems to back to behaving normally now since tightening up the connection outside. Unless anything else happens I shall leave until the tech comes to install the Tivo and connect the V+ downstairs. They will have put the splitter backin outside as a previous tech tidied up things when there was a problem (removed corroded bits and pieces).

The power level may not be real on one channel if the software doesnt allow enough bits to store it.

---------- Post added at 11:59 ---------- Previous post was at 11:58 ----------

Seems like the superhub can do multiple things except work correctly!:D

Thats why its called a SuperHub:erm:

craigj2k12
17-04-2011, 14:07
yes but when he has 4 channels the power levels are fine (downstream)

the upstream is still too high

pip08456
17-04-2011, 14:09
It is most likely the high upstream which is stopping the modem side locking onto more than one channel.

Bottom line - it needs sorting out by a tech.

Ignitionnet
17-04-2011, 14:27
the fact you had a single 42mbit channel give you full speeds suggests your area is very low utilised.

When I was down to a single channel I was able to only achieve around 20-25mbit on speedtests, and mine is QAM256 vs your QAM64. So in my area if they rolled this out on docsis1 tech I would be having performance issues.

Which is precisely why they didn't roll it out without bonding. 33Mbit/s is a big ask and nigh on impossible on 64QAM EuroDOCSIS due to overheads.

Area could be much more heavily utilised than that though, DOCSIS 3 is supposed to load balance to avoid heavily utilised downstream channels with bonded modems.

pip08456
17-04-2011, 14:41
Which is precisely why they didn't roll it out without bonding. 33Mbit/s is a big ask and nigh on impossible on 64QAM EuroDOCSIS due to overheads.

Area could be much more heavily utilised than that though, DOCSIS 3 is supposed to load balance to avoid heavily utilised downstream channels with bonded modems.

I like that word.:D

Ignitionnet
17-04-2011, 15:17
I like that word.:D

I've worked in IT for more than long enough to not use absolutes unless absolutely sure. What it's supposed to do and what actually happens with the software running on VM's CMTS could be different things.

Chrysalis
17-04-2011, 15:24
Which is precisely why they didn't roll it out without bonding. 33Mbit/s is a big ask and nigh on impossible on 64QAM EuroDOCSIS due to overheads.

Area could be much more heavily utilised than that though, DOCSIS 3 is supposed to load balance to avoid heavily utilised downstream channels with bonded modems.

yep and that was a (increasingly rare) good decision to use docsis3 from VM.

Neo-Tech
18-04-2011, 00:59
I've seen mine go as high as 40dBmV when I was faffing around with attenuators whilst clearing up wires. But obviously didn't get a lock on, if I did, that would be... :shocked:

arcimedes
18-04-2011, 07:38
I've worked in IT for more than long enough to not use absolutes unless absolutely sure. What it's supposed to do and what actually happens with the software running on VM's CMTS could be different things.

I agree. My experience in IT goes back pre IP to X25 and what I found was the switching software worked really good except when you got into error conditions which was the hardest part to test along with the interaction with the mainfame software.

When we were rolling 64Kbits connections we had no real problems until we tried to connect a Honeywell (I think) and then it wouldnt work!

Broken Hope
18-04-2011, 18:37
It is most likely the high upstream which is stopping the modem side locking onto more than one channel.

Bottom line - it needs sorting out by a tech.

I've had upstream power in the 55-56 range for as long as I can remember, mainly because every time I've had a tech out they have never been able to fix it.. I don't have any issues with my connection though.

arcimedes
18-04-2011, 18:51
I've had upstream power in the 55-56 range for as long as I can remember, mainly because every time I've had a tech out they have never been able to fix it.. I don't have any issues with my connection though.

I dont have any issues either after tightening up the connector in the outside box. At the moment its 58. If it aint broke dont try to fix it:)

Anyway when they put Tivo in and move teh SA box they will have to put the splitter back in outside box and then we will see how the hub behaves;)

jb66
18-04-2011, 20:32
TiVo doesn't like u/s over 55. Will be interesting, another appointment to fit an hdu maybe

Ignitionnet
18-04-2011, 22:26
TiVo doesn't like u/s over 55. Will be interesting, another appointment to fit an hdu maybe

If an HDU is required the local network needs lining up or a line extender installed to be honest.

Of course what actually happens... :)

Marcus125
18-04-2011, 22:31
If an HDU is required the local network needs lining up or a line extender installed to be honest.

Of course what actually happens... :)

Do you have much real world network exp?

Or is it all text book?

jb66
18-04-2011, 22:37
If an HDU is required the local network needs lining up or a line extender installed to be honest.

Of course what actually happens... :)

It could be a 29db tap. Sometimes I have to fit an hdu for two devices then heavily attenuate to get the downstream down