50M : Post RS Errors

[Ignitionnet]

Originally Posted by jb66

This is why Techs need better tools. I need a meter to plug into the taps and see that what the SNR is, if its poor pass to networks if not move to end of the drop, if poor book a repull if not move on.....

Same with upstream

Newer cable modems are basically full-capture spectrum analysers. They may issue those or, alternatively, as more of those arrive on the network they can just query them remotely for network conditions.

[jb66]

Originally Posted by Ignitionnet

Newer cable modems are basically full-capture spectrum analysers. They may issue those or, alternatively, as more of those arrive on the network they can just query them remotely for network conditions.

The problem with that is you need someone clever enough on the end of the phone to look at it rather than "book a tech" for a "closer look" with no diagnostic tools to scratch his head and swap out the hub again.

[Ignitionnet]

Originally Posted by jb66

The problem with that is you need someone clever enough on the end of the phone to look at it rather than "book a tech" for a "closer look" with no diagnostic tools to scratch his head and swap out the hub again.

Nah, just a decent front end that colours the numbers in lots of green / red / amber along with a workflow that shoves it in the agent's face before they're allowed to book a tech

[vm_tech]

Originally Posted by jb66

This is why Techs need better tools. I need a meter to plug into the taps and see that what the SNR is, if its poor pass to networks if not move to end of the drop, if poor book a repull if not move on.....

Same with upstream

I agree JB, upstream meters should be a necessity.

[Kushan]

Originally Posted by jb66

The problem with that is you need someone clever enough on the end of the phone to look at it rather than "book a tech" for a "closer look" with no diagnostic tools to scratch his head and swap out the hub again.

Originally Posted by Ignitionnet

Nah, just a decent front end that colours the numbers in lots of green / red / amber along with a workflow that shoves it in the agent's face before they're allowed to book a tech

I don't understand, Virgin already has this. It's called Red Tools. It shows all the modem stats, as well as a bunch of other stuff. It also lets you remotely reboot the hub and works for STBs as well.

Agents are trained on power levels and what to look for, acceptable SNR and that sort of thing. They have tools for monitoring all of the statistics, BADGER for utilisation, Cardie for noise and all first line agents are trained to use them. Failing that, second line can log straight into the UBR.

[Ignitionnet]

Originally Posted by vm_tech

I agree JB, upstream meters should be a necessity.

What are you hoping for an upstream meter to tell you?

[vm_tech]

Originally Posted by Ignitionnet

What are you hoping for an upstream meter to tell you?

The most common BB fault when I was a service tech was high upstream. To have a meter to give you a reading of what that was at a given point saves masses amounts of time.

[jb66]

One example is I can go to a house and the upstream is 49db and I think that's fine no fault there. But after I get a repeat fault my principal tech who has an upstream meter finds out the upstream at the taps is 34db. So I've lost over 10db on the drop so there must be a heatshrink or damage to it. I have no tools to check that

[Sephiroth]

Originally Posted by jb66

One example is I can go to a house and the upstream is 49db and I think that's fine no fault there. But after I get a repeat fault my principal tech who has an upstream meter finds out the upstream at the taps is 34db. So I've lost over 10db on the drop so there must be a heatshrink or damage to it. I have no tools to check that

Surely this is distance & frequency dependent, JB? For example taking 150m RG11 cable as the external example and 1m RG6 as internal with a 3.5dB splitter at the Omnibox you'd get attenuation as follows:

4.5 dB for 45.8 MHz
3.5 dB for the splitter (there may be one on the outside too)
0.6 dB for the 1m coax from the modem
----
8.6 dB total loss based on the assumptions

So without the parameters I've suggested being given, we have no way of knowing if a 10 dB loss on the drop is reasonable.

[jb66]

In the example the 10db loss was over the drop (tested at the omni), there was a damaged join under the lawn that caused the stinger to go rusty causing low frequecies to be blocked but allowed higher frequencies through. With correct tools it would have been a doddle to diagnose

[Jon22]

Right tech has been, was the same person as last time. He could immediately see there was a problem as his PDA was showing a fail on the upstream test. He could also see that the downstream SNR was low. Went off to the cabinet and adjusted the upstream there. So thats been lowered but he still wasn't happy with the downstream SNR. Rang up the same people who gave the CARDIE reading before and they said it was fine. I don't think he was convinced, so he rang networks and passed it on to them. They are going to monitor it over the next few days and the tech is going to call me back on Thursday. Stats are currently:

DS-1 DS-2 DS-3 DS-4 DS-5 DS-6 DS-7 DS-8
Frequency (Hz) 299000000 267000000 275000000 283000000 291000000 307000000 315000000 323000000
Lock Status(QAM Lock/FEC Sync/MPEG Lock) Locked Locked Locked Locked Locked Locked Locked Locked
Channel ID 13 9 10 11 12 14 15 16
Modulation 256QAM 256QAM 256QAM 256QAM 256QAM 256QAM 256QAM 256QAM
Symbol Rate (Msym/sec) 6.952000 6.952000 6.952000 6.952000 6.952000 6.952000 6.952000 6.952000
Interleave Depth I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17
Power Level (dBmV) 8.90 8.88 8.79 8.91 8.93 9.44 9.60 9.87
RxMER (dB) 33.72 33.72 33.60 33.60 33.96 34.08 33.83 34.08
Pre RS Errors 863274 9317351 11353577 5384277 1393045 13566411 429405 510327
Post RS Errors 128220 80392 107277 114269 164189 251900 183539 183389

Upstream
US-1 US-2 US-3 US-4
Channel Type 2.0 N/A N/A 2.0
Channel ID 50 N/A N/A 49
Frequency (Hz) 39400000 N/A N/A 46200000
Ranging Status Success N/A N/A Success
Modulation 16QAM N/A N/A 16QAM
Symbol Rate (Sym/sec) 5120000 N/A N/A 5120000
Mini-Slot Size 4 N/A N/A 4
Power Level (dBmV) 49.00 N/A N/A 48.96
T1 Timeouts 0 0 0 0
T2 Timeouts 0 0 0 0
T3 Timeouts 2 0 0 5
T4 Timeouts 0 0 0 0

Hopefully networks find something but I'm not overly convinced they'll sort it.

Does the fact that one of the upstream values ending in .x6 mean anything? I thought that the value incremented in .25 steps. I wonder if it's worth asking the lady I'm dealing with on the VM forum to perhaps send out another Superhub, just to rule it out.

[Jon22]

Had a call back from the tech (voicemail) and networks have told him there is a fault affecting the area but it's at the headend. It's being worked on at the moment. Think he's going to call back later, may have some more info.

[heero_yuy]

Figures: You've got a large increase in DS signal strength but no improvement in RxMER so the problem is upstream of you. Once it's all fixed up a FPA of about 6db would get everything in the right bounds.

[Sephiroth]

That's right. The high power amplified the noise!

[Jon22]

Any idea what they might be doing to fix it?