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4motions
04-06-2009, 03:17
Got my 50mb installed yesterday, however Ive noticed that most people have 3 downstream channels like this:

Frequency 299000000 307000000 315000000 N/A
Lock Status
(QAM Lock/FEC Sync/MPEG Lock) Y/Y/Y Y/Y/Y Y/Y/Y N/N/N
Channel Id 60 61 62 N/A
Modulation 64QAM 64QAM 64QAM N/A
Symbol Rate
(Msym/sec) 6.952 6.952 6.952 N/A
Interleave Depth I=12
J=17 I=12
J=17 I=12
J=17 N/A
Power Level
(dBmV) 4.62 4.51 4.68 N/A
RxMER
(dB) 34.72 34.87 35.20 N/A
Correctable
Codewords 0 1 0 N/A
Uncorrectable
Codewords 1005 252 717 N/A

However, this is the downstream info from my modem:

Frequency 299000000 307000000 315000000 323000000
Lock Status
(QAM Lock/FEC Sync/MPEG Lock) Y/Y/Y Y/Y/Y Y/Y/Y Y/Y/Y
Channel Id 35 36 37 38
Modulation 256QAM 256QAM 256QAM 256QAM
Symbol Rate
(Msym/sec) 6.952 6.952 6.952 6.952
Interleave Depth I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17
Power Level
(dBmV) -0.00 0.10 0.52 0.20
RxMER
(dB) 37.36 37.36 37.94 37.94
Correctable
Codewords 2 3 5 5
Uncorrectable
Codewords 277 261 259 279

Why is it Im using 4 downstreams and others are on 3

Thanks ;)

Peter_
04-06-2009, 08:17
Got my 50mb installed yesterday, however Ive noticed that most people have 3 downstream channels like this:

Frequency 299000000 307000000 315000000 N/A
Lock Status
(QAM Lock/FEC Sync/MPEG Lock) Y/Y/Y Y/Y/Y Y/Y/Y N/N/N
Channel Id 60 61 62 N/A
Modulation 64QAM 64QAM 64QAM N/A
Symbol Rate
(Msym/sec) 6.952 6.952 6.952 N/A
Interleave Depth I=12
J=17 I=12
J=17 I=12
J=17 N/A
Power Level
(dBmV) 4.62 4.51 4.68 N/A
RxMER
(dB) 34.72 34.87 35.20 N/A
Correctable
Codewords 0 1 0 N/A
Uncorrectable
Codewords 1005 252 717 N/A

However, this is the downstream info from my modem:

Frequency 299000000 307000000 315000000 323000000
Lock Status
(QAM Lock/FEC Sync/MPEG Lock) Y/Y/Y Y/Y/Y Y/Y/Y Y/Y/Y
Channel Id 35 36 37 38
Modulation 256QAM 256QAM 256QAM 256QAM
Symbol Rate
(Msym/sec) 6.952 6.952 6.952 6.952
Interleave Depth I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17
Power Level
(dBmV) -0.00 0.10 0.52 0.20
RxMER
(dB) 37.36 37.36 37.94 37.94
Correctable
Codewords 2 3 5 5
Uncorrectable
Codewords 277 261 259 279

Why is it Im using 4 downstreams and others are on 3

Thanks ;)
It depends on what area you are in.

Nothing to worry about or it could be that you are on one of the new Motorola BSR's that Virgin are installing at the moment in the exchanges.

lsproc
04-06-2009, 08:22
Thought Nottinghamshire wasnt done yet :dozey:

Peter_
04-06-2009, 08:24
Thought Nottinghamshire wasnt done yet :dozey:
To early for me but over that way:dunce:

ro53ben
04-06-2009, 09:28
4 channels bonded for me

Frequency 298750000 306750000 314750000 322750000
Lock Status
(QAM Lock/FEC Sync/MPEG Lock) Y/Y/Y Y/Y/Y Y/Y/Y Y/Y/Y
Channel Id 59 60 61 62
Modulation 256QAM 256QAM 256QAM 256QAM
Symbol Rate
(Msym/sec) 6.952 6.952 6.952 6.952
Interleave Depth I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17
Power Level
(dBmV) -2.05 -2.45 -2.43 -1.91
RxMER
(dB) 38.26 38.26 38.61 38.61
Correctable
Codewords 5079 4384 4682 4531
Uncorrectable
Codewords 6392 6057 5940 6097

Zhadnost
04-06-2009, 09:42
4 for me too, although only 3 are working. What I find more interesting is that some peoples config file names are gibberish and (well mine) isn't.

Peter_
04-06-2009, 10:09
4 for me too, although only 3 are working. What I find more interesting is that some peoples config file names are gibberish and (well mine) isn't.
It will show 4 channels but in the main just 3 work depending on area and exchange.

Zhadnost
04-06-2009, 11:08
4 were working up until yesterday, now the 4th ones error count is going through the roof and I lose my internet connection every 30 seconds to 20 minutes.

Sometimes it drops all the DS channels one at a time.

Got engineer visit booked for tomorrow morning.

4motions
04-06-2009, 16:46
Thanks for letting me know, was thinking I was special getting 4 channels instead of 3 :P

One thing I was wondering, could someone tell me if my signal levels are ok? Not sure what the recommended range is for the 50mb

Downstream

Power Level
(dBmV) -0.00 0.10 0.52 0.20

Upstream

Power Level
(dBmV) 39.00

Thanks

ro53ben
04-06-2009, 17:39
The downstream level should be between minus 7 and plus 7 for 50meg, same applies to 20 meg. Yours look perfect to me.

4motions
05-06-2009, 01:23
The downstream level should be between minus 7 and plus 7 for 50meg, same applies to 20 meg. Yours look perfect to me.

Thanks for the help, wasnt sure if the level was different for 50mb. Now I just need to try and reduce my ping times :)

Ignitionnet
05-06-2009, 09:22
It will show 4 channels but in the main just 3 work depending on area and exchange.

If a customer is synced to 4 channels all 4 should work - the information on what channels are active comes from the CMTS. Modem ranges to primary downstream which sends it an MDD message giving info on where the other active downstreams are.

When you see a customer with a wideband modem that is only synched to 299 / 298.75 you'll probably find it accompanied by an MDD message timeout.

Peter_
05-06-2009, 10:01
If a customer is synced to 4 channels all 4 should work - the information on what channels are active comes from the CMTS. Modem ranges to primary downstream which sends it an MDD message giving info on where the other active downstreams are.

When you see a customer with a wideband modem that is only synched to 299 / 298.75 you'll probably find it accompanied by an MDD message timeout.
Could please clarify what MDD is and apart from that my answer is correct as that is what we see on modems from various areas.

Ignitionnet
05-06-2009, 10:05
Could please clarify what MDD is and apart from that my answer is correct as that is what we see on modems from various areas.

MDD - MAC Domain Descriptor - it's the details of the active downstream channels in the bonded groups.

I know what you mean I just meant that if you can see a downstream channel locked it should be working as the CMTS told the modem it was active, if it's blank you're usually fine, apart from Zhad who loses channel 4 due to a dodgy modem or downstream path :)

---------- Post added at 09:05 ---------- Previous post was at 09:03 ----------

The downstream level should be between minus 7 and plus 7 for 50meg, same applies to 20 meg. Yours look perfect to me.

It's not that narrow a range for 20Mbit or 50Mbit, but depends on a few things.

20Mbit should work alright +/- 10dBmV or more and 50 should be alright to around the +/- 10dBmV mark. I know sometimes it doesn't though :(

Peter_
05-06-2009, 10:07
MDD - MAC Domain Descriptor - it's the details of the active downstream channels in the bonded groups.


Thanks ;)

ro53ben
05-06-2009, 11:20
It's not that narrow a range for 20Mbit or 50Mbit, but depends on a few things.

20Mbit should work alright +/- 10dBmV or more and 50 should be alright to around the +/- 10dBmV mark. I know sometimes it doesn't though :(

I was running at around +10 and my line was very unstable. I was advised by senior technicians it's because this figure was too high. They sent out an engineer to adjust the line accordingly to ensure it was +/- 7dBmV which, I'm told, are the required parameters. The line became more stable.

I'm not going to argue with you about what it should or shouldn't be, I'm no expert on this, but I am going to claim from experience that having a rating within that narrower range is definitely more stable which is why they sent an engineer to adjust it.

Zhadnost
05-06-2009, 12:45
Apart from Zhad who loses channel 4 due to a dodgy modem or downstream path :)


Sounds like the latter.

Got a call this morning (probably from the woman who was supposed to assist the install).

Apaprently they're having a problem with one of the UBRs (her words not mine, I still prefer the term CMTS).

So it's apparently an area fault and according to reports I shouldn't be expecting speeds greater than 1Mbit (I'm still getting 50 while it's working), the reason why I keep getting cut off is probably due to them working on it (for 2 days?). They don't have an anticipated time to fix.

ro53ben
05-06-2009, 13:02
Which area was this?

Zhadnost
05-06-2009, 13:09
Southampton

ro53ben
05-06-2009, 13:11
Thanks. I get similar symptoms, but I'm not near there :S