NTL Issues in Hot weather

[slacky]

Hi All,

This is my first post here, but I wont bore you with stuff about me.
Hopefully though, I can bore you with an issue I am having as of late.
Basically, any time there is sustained warm weather, I get drops outs to my VM 20MB connection.
The symptoms are:

*Internet drops out. Unable to browse to web by URL or IP.
*Can still see my gateway just fine (Cisco ASA 5505) and can also HTTP to the NTL:250 which is *outside* of my ASA, in other words, traffic is passing perfectly through my kit. Debugs show the same.
*In order to get the connection back I usually have to reboot the Cable modem.
*The room is air conditioned, so it isnt related to the heat of the Modem/Firewall, I'm thinking more along the lines of the box on the street?
*Nothing in the NTL:250's logs that looks particularly alarming.
Is there anything else I can try? 25p/Min sounds rather harsh for me to report a fault so I hoped somebody here had a suggestion?

Thanks for any help you can provide :D :dunce:

[fatassmichael]

Can you post the power levels from the modem.

[slacky]

Hi Mate,

Currently the internet is "back". But the power levels are at:

Downstream Receive Power Level : -9.6 dBmV
Downstream SNR : 37.9 dB

Upstream transmit Power Level : 40.0 dBmV


Just got off the phone with VM Techs. Even though I have tried this with a Cisco ASA firewall, a Cisco 1721 router and directly connected to the modem over the last few weeks, they say there is no fault :(
They want me to directly connect to the modem again....oh well.


Thanks for your response :)

---------- Post added at 20:51 ---------- Previous post was at 20:46 ----------

Forgot to say, the Line has a "15db Forward Path attenuator" on it, fitted by an NTL engineer long ago.

[Hugh]

Slacky, I know you said the room is air-conned, but is the modem in a cupboard/enclosed shelf with other equipment?

[RedDragon]

If the box you are refering to is a waist high green cabinet, it contains an amplifier which can get a bit too hot if in full view of the sun. This can cause a drop in signal levels of a few dB, this is not normally a problem unless your return path signal is maxing out at 59 to 61 dB in which case your modem will drop out on a sunny day.

---------- Post added at 20:59 ---------- Previous post was at 20:56 ----------

Sorry, bit slow posting back there. The upstream seems ok but I would be worried about the downstream, -9.6 is too low for a consistant connection.

[slacky]

Well the VM tech seemed happy that there was nothing wrong, and that my £500 firewall was to blame :o:

Anyway, thanks for the response, ill quiz them about the downstream next time the connection drops out! Thanks guys, much more helpful than the VM call centre girl!

---------- Post added at 21:29 ---------- Previous post was at 21:03 ----------

Slacky, I know you said the room is air-conned, but is the modem in a cupboard/enclosed shelf with other equipment?

Hi mate,

No, they are in the open and very well ventilated.

[Axegrinder]

I had this problem today

The sync light went out and lost connectivity...so i checked the power levels and the upstream was hitting 61db and staying there for a good few hours, then the sync light came back on but the ready light kept flashing.

[sollp]

Hi All,

This is my first post here, but I wont bore you with stuff about me.
Hopefully though, I can bore you with an issue I am having as of late.
Basically, any time there is sustained warm weather, I get drops outs to my VM 20MB connection.
The symptoms are:

*Internet drops out. Unable to browse to web by URL or IP.
*Can still see my gateway just fine (Cisco ASA 5505) and can also HTTP to the NTL:250 which is *outside* of my ASA, in other words, traffic is passing perfectly through my kit. Debugs show the same.
*In order to get the connection back I usually have to reboot the Cable modem.
*The room is air conditioned, so it isnt related to the heat of the Modem/Firewall, I'm thinking more along the lines of the box on the street?
*Nothing in the NTL:250's logs that looks particularly alarming.
Is there anything else I can try? 25p/Min sounds rather harsh for me to report a fault so I hoped somebody here had a suggestion?

Thanks for any help you can provide :D :dunce:

Where abouts in the country are you?

[AbyssUnderground]

Mine dropped about 9.20pm today and didn't return till 10.20pm. It did this the other day at around the same time. Sync totally lost, no signal. Also my router reset to factory defaults which was odd (but I was messing with it at at the time).

[monkey2468]

Hmm, makes you wonder which bright spark decided to repaint all the green cabs round here to MAT BLACK!!!!! |Obviously didn't do science at skhuul!:)

Edit: just from experience (ex-employee) I know that some old cable networks (before the ntl: buyouts) that they didn't add any cooling fans to the main cabs (50p?).

[slacky]

Where abouts in the country are you?

Hi,

I'm in Kirklees in west Yorkshire. For the record, the light status always seems "normal", even during the outages *shrugs*

[monkey2468]

Hi,

I'm in Kirklees in west Yorkshire. For the record, the light status always seems "normal", even during the outages *shrugs*
Huddersfield or Dewsbury?
Doesn't matter though as they were decently (ish) build netwok.
What do you mean by status light?

[slacky]

I mean the status lights on the NTL:250. It doesn't appear to lose sync, the send and receive lights just stop flashing and that's about it.

[DocDutch]

slacky when this happens can you ping the modem at all (192.168.100.1) and see if you drop any packets then?

ALso what I've had when I had 1 of those "lovely" attenuators was that my line was more off then on so took it off and it was fine after that.

---------- Post added at 13:17 ---------- Previous post was at 13:16 ----------

ps forgive my rudeness and lemme :welcome: you here

[slacky]

slacky when this happens can you ping the modem at all (192.168.100.1) and see if you drop any packets then?

ALso what I've had when I had 1 of those "lovely" attenuators was that my line was more off then on so took it off and it was fine after that.

---------- Post added at 13:17 ---------- Previous post was at 13:16 ----------

ps forgive my rudeness and lemme :welcome: you here

Hiya :)

Yes, i can get to the modem just fine, either via continuous ping or by HTTP to the devices admin page. I have tried removing the attenuator and the line dropped out shortly afterwards :(