Erratic connections - getting nowhere with NTL support

davidsi · 05-04-2006, 21:31

Since NTL apparently "reoptimized" the UBR that I use last week I've been suffering from connections which most of the time work absolutely fine but every so often appear to glitch perhaps with packet loss but I have been unable to prove that. I've now been onto NTL several times and each call has resulted in a different story and there's been no resolution.

The problem is most noticable when using ssh (or microsoft remote desk top) to another system over my 2Mb NTL connection. Everything works fine, but then the connection will appear to freeze for several seconds - it eventually recovers. This had all been working fine since christmas and had never had a problem up until last week.

Unfortunately when I call support its seems impossible for them to see what the problem could be mainly because I'm clearly able to surf the net and access other systems so as far they can see it works. Anyone got any ideas?

I'm in the luton franchise area and the UBR is the Hatfield one. Although I normally use a linksys wireless router I have also tried directly connecting (wired) to my terrayon cable modem and it is still a problem. I've also tried with both my PC (Win XP) and my MAC.

Chrysalis · 05-04-2006, 22:27

the freezing is caused by contention and will probably not happen at 5am

I have had this problem for a few months now.

Try power cycling your modem so it goes onto a different upstream it may improve things.

isf · 06-04-2006, 00:25

Me too, the internet has been barely useable since whatever 'upgrades' NTL performed in their Fri 27th maintenence . My SSH connection locks up and webpages freeze or fail to load at all. I'm seeing moderate packet loss but the problem is intermittent which makes it hard to diagnose.

davidsi · 08-04-2006, 08:37

I don't think it can be contention. I've tried at many different times of day/night and the basic problem still exists. At quieter times of the day overall performance is better but I still see connections freezing and like isf webpages failing to load. I've tried powering off/on several times and that too seems to make little difference.

James Henry · 08-04-2006, 11:50

Quote:

Originally Posted by davidsi

I don't think it can be contention. I've tried at many different times of day/night and the basic problem still exists. At quieter times of the day overall performance is better but I still see connections freezing and like isf webpages failing to load. I've tried powering off/on several times and that too seems to make little difference.

Sounds like noise on the upstream or downstream, possibly your area has been optimised for extra bandwidth but you connection isn't a good enough quality to support this optimisation, or you've been moved to an upstream channel that's noisy in your area.

All you can do is try tech support again and perhaps if you can't get though one of the moderators here could assist.

IanGuy · 08-04-2006, 12:11

I have been having the exact same problems as you since about a week ago. Online gaming has become impossible, when ringing CS they just say we can't see any problems sir. And due to both sync and rdy lights being solid they quite simply state it's a problem with my pc, which I know for a fact is not true. When I reboot the modem, it seems to get a better upstream signal but this only lasts an hour or so, then my connection goes back to "normal".

It seems that it's definitely a problem with upstream, packet loss has been as high as 68.4% on some days when tracert'ing www.google.co.uk

isf · 08-04-2006, 15:14

IanGuy,

Traceroute cannot be used to measure packet loss. Once you have done a trace, you need to ping each host after your STB/modem, this is also the only way to determine where the packets are being dropped. So with a trace like this:

Quote:

traceroute to www9.thdo.bbc.co.uk (212.58.224.55), 30 hops max, 52 byte packets
1 ROUTER (x.x.x.x) 1.198 ms 1.265 ms 1.184 ms
2 STB (x.x.x.x) 12.999 ms 22.547 ms 11.266 ms
3 bagu-t2cam1-a-v119.inet.ntl.com (80.5.162.77) 9.134 ms 9.980 ms 13.416 ms
4 bagu-t2core-a-ge-wan63.inet.ntl.com (80.5.161.17) 12.465 ms 9.683 ms 13.291 ms
5 ETC...

first ping the host immediately after your STB/modem and work outwards until you find where the packets are being lost. You also need to make sure you have a decent sample size for a % figure to be meaningful, on windows I would use:

Quote:

ping -n 100 x.x.x.x

My issue was packet loss between STB and the next hop, spoke to customer support earlier, they told me there was a power level issue and booked an engineer for Monday morning. After they ran the diagnostic AGC was down to 47% from 64 and I'm now seeing a consistant 1% packet loss (100 pkts). HTH.

Stuart · 08-04-2006, 15:27

Quote:

Originally Posted by davidsi

Since NTL apparently "reoptimized" the UBR that I use last week I've been suffering from connections which most of the time work absolutely fine but every so often appear to glitch perhaps with packet loss but I have been unable to prove that. I've now been onto NTL several times and each call has resulted in a different story and there's been no resolution.

The problem is most noticable when using ssh (or microsoft remote desk top) to another system over my 2Mb NTL connection. Everything works fine, but then the connection will appear to freeze for several seconds - it eventually recovers. This had all been working fine since christmas and had never had a problem up until last week.

Unfortunately when I call support its seems impossible for them to see what the problem could be mainly because I'm clearly able to surf the net and access other systems so as far they can see it works. Anyone got any ideas?

I'm in the luton franchise area and the UBR is the Hatfield one. Although I normally use a linksys wireless router I have also tried directly connecting (wired) to my terrayon cable modem and it is still a problem. I've also tried with both my PC (Win XP) and my MAC.

Please PM me your name, address, account number and a daytime phone number, and I'll refer this to our contacts.

to the forum BTW.

IanGuy · 08-04-2006, 17:34

Quote:

Originally Posted by isf

IanGuy,

Traceroute cannot be used to measure packet loss. Once you have done a trace, you need to ping each host after your STB/modem, this is also the only way to determine where the packets are being dropped. So with a trace like this:

first ping the host immediately after your STB/modem and work outwards until you find where the packets are being lost. You also need to make sure you have a decent sample size for a % figure to be meaningful, on windows I would use:

My issue was packet loss between STB and the next hop, spoke to customer support earlier, they told me there was a power level issue and booked an engineer for Monday morning. After they ran the diagnostic AGC was down to 47% from 64 and I'm now seeing a consistant 1% packet loss (100 pkts). HTH.

This still doesn't explain connection interrupts while gaming, absolutely nothing has changed with my system, i've run virus checks, i have no adware/spyware and my processes are minimal. I get random spikes in all games, on all servers aswell as MSN Messenger getting signed off frequently - simple answer: NTL's problem not mine.

John S · 08-04-2006, 17:52

Ive had something similar to this freezing/contention/whatever for weeks.
Sometimes in the morning and evening it is OK but now its started with Email.
Ive run virus checks adaware and disaabled the firewall changed mice etc etc.
Ive just disconnected the modem cable and everything is fine connect up the modem again and its freezing again.
Any suggestions please.

John.

isf · 09-04-2006, 14:05

Quote:

Originally Posted by IanGuy

This still doesn't explain connection interrupts while gaming, absolutely nothing has changed with my system, i've run virus checks, i have no adware/spyware and my processes are minimal. I get random spikes in all games, on all servers aswell as MSN Messenger getting signed off frequently - simple answer: NTL's problem not mine.

Is your actual connection going down or are you experiencing packet loss?

IanGuy · 09-04-2006, 15:11

I experience packet loss, but also at times the RDY light does actually go off, but then the modem cycles automatically.

davidsi · 09-04-2006, 15:21

Quote:

Originally Posted by IanGuy

I experience packet loss, but also at times the RDY light does actually go off, but then the modem cycles automatically.

That sounds like a slightly different set of symptoms to what I see - my modem light is absolutely always on, and even when one connection may be 'hanging' I can make other connections without any problems.

isf · 09-04-2006, 15:23

Quote:

Originally Posted by IanGuy

I experience packet loss, but also at times the RDY light does actually go off, but then the modem cycles automatically.

Nothing in the error log on your STB?

IanGuy · 09-04-2006, 15:51

I've got this in my modem error log -

1Time Not EstablishedFRI APR 07 13:25:14 2006 19583Critical (3)82000200No Ranging Response received - T3 time-out