Investigating intermittent NTL disconnections

fatherdougalmag

I'm having intermittent problems with my broadband service. I was on to tech support at the beginning of last week and a very helpful guy tried to talk me through the set-top box 'Help' page to see what values were on the right-hand side of the screen. Unfortunately I was in work but in mid conversation he could confirm that there were NTL problems in my area and that they had been resolved. But now I'm still getting periods of about 40 mins with no connection. So, in an effort to gather as much info as I can, I want to keep tabs on the STB values on the help page. The tech specifically mentioned values 3 and 5 and gave me guideline values of less than 75 (for field 3) and 28 or 29 (for field 5).

So does anyone know what these values represent? I can't find anything on the web about them. I am getting a value of anywhere between 37 or 38 for value 5. Can't remember what value 3 was but I have it written down at home.

During these down-times, the RDY light flashes but the SYNC is solid so it's like the modem isn't receiving valid params (IP address, gatway, DNS, etc.) During this down-time the signal read 38. When the connection came back it was 37.7 so it doesn't look like there's anything significant there. None of the other values changed (much).

So if anyone looking on knows what these values represent it might make more sense to me.

Serbian

Sorry, can't help you with the values you mention above, but it might be worth mentioning the general area you are in to see if people in the same area are also having problems.

Propocus

I have been having similar problems. I have never been disconnected but over the last few weeks I either get connected immediately, get connected after an hour or two, or don't get connected all. When this problem is occuring my modem is behaving exactly as yours - RDY flashing but SYNC is solid. I rang NTL today and they suspect that the modem is faulty - they are coming out next week to have a look. Has your situation resolved itself?

fatherdougalmag

I'm in Saggart.

I provided pings and traceroutes to NTL support and they said it was the PC/router that I had connected to the modem.

At this stage I have tried a Belkin wireless router (which I have been using for the past 1.5 years without problems - on the WAN side anyway). I have tried a VoIP analogue telephone adapter which doubles up as a router. This was then connected to my Belkin. That also showed problems (i.e connect/disconnect sequences every 15/20 seconds or so). I'm beginning to think that both the VoIP router and Belkin are misbehaving when I have more than one PC active at a time. I have a laptop connected via wireless and a PC connected to the switch. Although, I can't think why this is happening recently. Unfortunately, I'm not at home when the outages occur so I don't know what the LEDs are up to. And because of the nature of the problem (intermittent) it's hard to ring the other half and have her check the LEDs every 5 mins. I'll see how things are over the weekend.

I have occasionally seen the modem's RDY LED flash for prolonged periods of time. I think the RDY LED flashes whilst it's getting an IP address from NTL. The SYNC means that the communications (layer 1 & 2, if you like) are OK.

I'll be spending the weekend pinging the modem's default gateway (using NetPing) and logging up/down events. I'll also note the LED status on the modem and I'll only allow one PC to be connected to the service. If I've no downtime during all of this I can probably be sure its my router that's croaked/croaking.

jimmycrackcorm

I had problems with disconnects using BitTorrent but I updated my router firmware and that slved the problem.

causal

You've a STB, but my cable modem has these values:

Downstream Receive Power Level : -1.56 dBmv
Downstream SNR : 34.63 dB
Upstream Transmit Power Level : 42.00 dBmv

You can check desirable CM levels here.


hth,
causal

CiaranC

Having similar problems in Tallaght

fatherdougalmag

I was monitoring things over the weekend. Of course, the time when I'm in a position to run customer support when I can see the modem LEDs and it barely goes down. Still had a couple of outages though. I did start looking at the signal levels during these downtimes and I did notice that the upstream level dropped to 21 or so. When the connection is up, this is typically arounf the 45 mark. So that's something else that I'm going to be watching. I'm trying to develop a util which will pull down the signal strength levels from the modem configuration page every few seconds. I've got a mate down the road on NTL and he's having intermittent problems too so he's keep check too.

fatherdougalmag

Well I rang up today to get bumped down to 1Mbps and I mentioned my observation in passing to the tech. He just asked if I had gone through tech support (as opposed to the upgrade/downgrade/cancellation gang that he was on). I said that I had but I was getting nowhere. He said that I had been put down to 1Mbps and that he'd see if there's any related problems out my way.

When I got home (I had asked the missus to reboot the modem) I noticed that my d/l speed was still 2Mbps but my upstream signal strength has jumped to a whopping 59! So he (or someone) obviously tweaked something on their end (no site visit). As far as I know, 59 is quite high and might actually introduce problems in itself. But, for now, I'll just monitor things and hopefully it'll be an end to my problems. I did find solace over on NTL Hell as some people were in the same position I was. Other's also reported exceedingly high or low downstream values and reported intermittent problems.

So if you experience any probs like this, it's worth having a look at the signal strengths on the modem to see if there's any relationship between the signal strength and your downtimes or wobbly connections.

Propocus

Well the modem guy from NTL came out last Saturday and I hadn't had
the same problems for a couple of days - it turned out they added another fibre optic cable to our service area. It seems they suspect a noisy modem somewhere but its proving difficult to find. So the workaround is another cable...

RicardoSmith

My NTL has been down for 3 days. The sync light is on but the rdy light just flashes steadily. Getting so common now that I'm thinking of cancelling it.

fatherdougalmag

Whereabouts are you Propocus?

RicardoSmith, have you been on to tech support? You could also post your signal strengths just so we can compare.

RicardoSmith

fatherdougalmag wrote:

Whereabouts are you Propocus?

RicardoSmith, have you been on to tech support? You could also post your signal strengths just so we can compare.

Quite a few times at this point. They usually say they'll ring me back and most of the time they don't. When I do get to talk to them they tell me all sorts of nonsense, theres a problem and they are working on (for like 9 months? some problem..) or its the order I turn my computers on or some other such rubbish. The connection comes and goes regardless of whats happening with my equipment. So even if you knew nothing of IT common sense would tell you its a NTL problem. Even without the connection problems my pings have been woeful from day one. They've never improved regardless of anything NTL say they done. Basically the service is as bad is it was from day one.

I've never managed to get on to that admin site. Mind you I'm not connecting directly to the modem. I'll have go at that later.

My line fails the DSL test do that isn't an option for me, and to be honest after my experience with Eircom and NTL and not too confident that I'd a better conection with IBB. I considering simply using the web at work and ditching it at home. You just can't rely on it.

I'm back on dialup @ 34k. Its wonderful... :mad:

fatherdougalmag

If I was you (and it was something I nearly did) I'd tell them there's something wrong with your set top box or there's no reception on some channels, just to get them to come out. Then mention/show the techy the modem and he might do something for you.

RicardoSmith

fatherdougalmag wrote:

If I was you (and it was something I nearly did) I'd tell them there's something wrong with your set top box or there's no reception on some channels, just to get them to come out. Then mention/show the techy the modem and he might do something for you.

In fact I do have a problem with reception on the TV and someone is comming out too look at that today. But they said there was a line down in our area which was repaired and I shouldn't have a problem. But I do.

How do I check the signal strenght again. Admin settings on the modem. It has to be connect direct to the Laptop to do this I think yeah?

fatherdougalmag

You should go to http://192.168.100.1 user admin, password admin (or root/root). I have no problem accessing this indirectly (through two routers). On the main page, you should see figures for D/S Power Level, D/S SNR and U/S Power Level.

Alternatively, use DOCSDIAG to do all this for you. If you're on XP you'll need the Java Runtime and then just give the command: java -jar docsdiag.jar.

RicardoSmith

fatherdougalmag wrote:

You should go to http://192.168.100.1 user admin, password admin (or root/root). I have no problem accessing this indirectly (through two routers). On the main page, you should see figures for D/S Power Level, D/S SNR and U/S Power Level.

Alternatively, use DOCSDIAG to do all this for you. If you're on XP you'll need the Java Runtime and then just give the command: java -jar docsdiag.jar.

Thanks, I'll try that and let you know what I get.

RicardoSmith

This is what I got.

Downstream Lock : Locked 
Downstream Frequency : 402000000 Hz 
Downstream Modulation : QAM64 
Downstream Interleave Depth : 32 
Downstream Receive Power Level : -15.5 dBmV 
Downstream SNR : 31.1 dB 

Upstream Channel ID : 1 
Upstream Transmit Power Level : 17.0 dBmV 
Upstream Symbol Rate : 1280 Ksym/sec 
Upstream Frequency : 21008000 Hz 
Upstream Mini-Slot Size : 4 

What do you think?

Propocus

fatherdougalmag wrote:

Whereabouts are you Propocus?

RicardoSmith, have you been on to tech support? You could also post your signal strengths just so we can compare.

I am in Dublin 15, Blanchardstown and haven't had any problems since the
extra cable was put in the area - on 2MB and getting pings of around 40 ms
to www.jolt.co.uk.

RicardoSmith

Propocus wrote:

I am in Dublin 15, Blanchardstown and haven't had any problems since the
extra cable was put in the area - on 2MB and getting pings of around 40 ms
to www.jolt.co.uk.

The NTL guy called out. Theres a porblem with cable in the road. The levels are too low. They have to send someone else out to find the problem with that. So no BB till next week.

fatherdougalmag

Well at least the problem has been root caused. Your signals are way way out. Look here. The lowest my upstream dropped to was 25 and that was enough to cause my BB to bomb out. You're at 17!! Your downstream is right on the limit.

At least you know now how to check your levels so in future outtages, you'll be able to provide tech support with tangible values.

RicardoSmith

fatherdougalmag wrote:

Well at least the problem has been root caused. Your signals are way way out. Look here. The lowest my upstream dropped to was 25 and that was enough to cause my BB to bomb out. You're at 17!! Your downstream is right on the limit.

At least you know now how to check your levels so in future outtages, you'll be able to provide tech support with tangible values.

Its too low even for the TV signals. Anything at the end of the band is unwatchable. at least theres some hope of a fix now instead of the babble you get on the phone from the cable support team.

capistrano

RicardoSmith wrote:

This is what I got.

Downstream Receive Power Level : -15.5 dBmV 
Downstream SNR : 31.1 dB 
Upstream Transmit Power Level : 17.0 dBmV 

What do you think?

These figures are terrible. When I got NTL last December my power levels were similar to those and the service was crap. I had an old junction box that was causing the power level to fall. They replaced the box and now everything is more or less okay (still the odd infrequent outage sadly). I also noticed that the picture quality on the analogue channels improved too.

FYI, my figures are:

Downstream received signal power     = 2.1 dBmV
SigQu: Signal to Noise Ratio         = 35.6 dB
Upstream transmit signal power       = 61.0 

RicardoSmith

RicardoSmith wrote:

This is what I got.

Downstream Lock : Locked 
Downstream Frequency : 402000000 Hz 
Downstream Modulation : QAM64 
Downstream Interleave Depth : 32 
Downstream Receive Power Level : -15.5 dBmV 
Downstream SNR : 31.1 dB 

Upstream Channel ID : 1 
Upstream Transmit Power Level : 17.0 dBmV 
Upstream Symbol Rate : 1280 Ksym/sec 
Upstream Frequency : 21008000 Hz 
Upstream Mini-Slot Size : 4 

What do you think?

Well they've fixed it...

Downstream Modulation : QAM64 
Downstream Interleave Depth : 32 
Downstream Receive Power Level : 6.4 dBmV 
Downstream SNR : 35.4 dB 

Upstream Channel ID : 5 
Upstream Transmit Power Level : 43.75 dBmV 
Upstream Symbol Rate : 1280 Ksym/sec 
Upstream Frequency : 22992000 Hz 
Upstream Mini-Slot Size : 4 

Oddly enough I was told it would take a couple of days and they couldn't give me a date.