Poor cable performance

[Fat Tone]

HI guys.
After a few days of no change, I'm wondering if this is more than a temporary NTL problem and I'm looking for help...

Initially when NTL set me up, I could only get web sites working through a proxy they suggested. Now it makes no difference - they all work but I never get more than ~9 k/sec. Downloads can be great - up to ~70K/sec, but never just browsing.

Any suggestions gratefully received. Oh, incase you didn't read my last thread, I have a 3COM905-TX attached to a RT314 router (this makes no difference to speed BTW), attached to a Terayon TJ210 cable modem.

Thanks in advance, Tony.

[Kosh Naranek]

I don't know much about routers, so no help there !

For cablemodems check out these sites :

http://cable-dsl.home.att.net

http://speedguide.net/Cable_modems

Speedguide also have a TCP/IP analyzer which can tell you if your TCP/IP is set up for a broadband connection !

http://www.dslreports.com

http://www.pcpitstop.com

If downloads are great up to ~70k/sec then I see no problem at all, because that's just how things are.Some sites just can't/won't give you more than a few K/sec and that's even when you have a 2048 Mbit connection.

BTW
The one thing which greatly affects download speed is the size of your "Recievewindow" .. a registry setting under TCP/IP, but the links will tell.

[Fat Tone]

Thanks for that, Kosh. I'll do some more reading!

Cheers

Tony.

[Jammrock]

There is also another issue with cable/cable modems. Sometimes one of the cable devices will eat more power than the lines can provide and it causes troubles. If your cable starts dropping while you are surfing, then you are having signal troubles. If there are signal troubles you'll need a cable maintanence guy to come out and split the cable/modem lines and add a signal amplifier on the cable line (you can't put an amp on the modem line since the amp is only one way and modem needs two way communication).

The other possibility is that your cable tree is overloaded. The most major downfall of cable in its current form is that an entire neighborhood shares the bandwidth. If there are a lot of people around you with cable modem and they are on a lot, your speeds will be greatly affected. Test your speeds using downloads and online bandwidth meters during various times in the day. If there are large speed differences between morning evening and late, late night, then your cable tree is overloaded.

Jammrock

[Fat Tone]

Thanks Jammrock.

NTL said they can check signal strength from the comfort of their desk and that it was ok. When you say drops, I haven't noticed that (I presume you mean the modem will have to re-register).
I've checked performance at all times of day, week and weekend. Downloads are usually fine, and browsing is always slow
So far I'm not impressed with it for £25/month.
I've looked at a few tweak guides, so I'm gonna try some of their suggestions tonight. I have messed with MTU in the past, and I suppose its possible I'm getting a hangover from that?

Cheers

Tony.

[Gurm]

I'd be suspicious of the MTU. This is easy to check.

Step 1: Pick a site that you know is running slowly, and/or not at all... but that SHOULD be ok.

Step 2: Start a DOS box.

Step 3: Ping the site with the following ping line:

ping -f -l xxxx site.site.site.com

-f means no packet fragmentation
-l xxxx means packet length of xxxx

Now... you SHOULD be able to ping that site with a packet length of around 1470. If you can't, it's most likely that your cable company has a screwy maximum MTU. Lower that -l xxxx number until you start getting responses.

My DSL provider requires me to drop my maximum MTU to around 1435... instead of the default 149x (1500). The tweak guides will help you figure out how to change your MTU.

If you are using Windows XP the only option to drop your MTU is to install a third party PPPoE driver... which is a pain and probably not applicable to you.

- Gurm

[Taz]

If NTL are like Telewest, (Blueyonder), then they are probably running transparent proxies, this would account for the slow web access but fast download speeds. You wont be able to switch off their proxy as all trafic on port 80 i.e. HTTP, will pass through it, the only solution is to bypass it by using someone elses proxy. The problem with this is your then dependant on the performance of that proxy.

Here is a list of public proxies you can try.

[DentyCracker]

Spoke to the C&W technicians today. They will be providing PPPOE service. I've installed a 10Mbit/sec NIC in the server at work to link to their Alcatel DSL "modem". I downloaded and installed RASPPPOE, and bound it only to that LAN cord. Even made a dial-up networking connection.Hopefully soooon I'll be up and running.

[Fat Tone]

Problem solved!

http://www.dslreports.com/tweaks is THE place to go! Thanks for that link Kosh. It told me my RWIN was at 2144 and confirmed my ~7k/sec. Once I upped it to 5840 it was browsing at about the same speed as downloads, but with a few packets lost. I doubled it to 11680 and saw a slight increase in speed and no packet loss over several tests! Sure it may be possible to tweak it some more but now I'm very happy with my cable connection!!

Before finding that I'd spent another hour on the phone to NTL. I don't think he had even heard of MTU or RWIN etc.

Thanks for all the help guys.

Tony.

PS good luck Denty!

PPS Gurm I couldn't ping murc with any length before the change, but I could www.bbc.co.uk

[Jammrock]

Good news! My internet connection is pretty fast, I wonder if I can juice it some more with RWIN...

Thanks for the advice!

Jammrock

[Fat Tone]

Life is sweet now, aint it!

[Fat Tone]

Hey Jammrock, Denty - How fast are you guys browsing now? Have you done any tests on upload speeds?

Tony.

[cbman]

Phone Company's End

Most times except weekends I get an average of 54 to 90 Kbytes a second Downloads

On Weekends this drops dramatically (Down to 25-40Kbytes)

I was talking to the owner of the store I "work" for and he has worked out a system with BMTS (Local Phone Provider) on signing up people with DSL.

He said he was talking with one of the head guys in the tech department at the phone company and he says that they only have 3 T1's Feeding the whole area's DSL network.

so that would mean that at

3*1.54Mbits = 4.62Mbits

So if there are any more than (960 - overhead bits download rate = ~850 Kbits) 4.62M/850K or 4620000/850000 = 5

Good thing T1's are (may not be correct terminology) Multiplexed.

24 DS0's * 3 = 72 @ DS0 using time multiplexing (Again.. more than likely wrong terminolgy)

Anyways... it all comes down to not enough bandwidth during peak times...

Of course this could be way off...

Its been a year or two since I took Broadband in college and they were just coming out with the Nortel Meg Modem at the time... (We got to play with one.... talk about interesting stuff at the time)

Oh and I also found out that they don't have a bandwidth limiter on their end so if I can find a high speed DSL modem I should be able to pull off some really high speed access (Until they catch on)

[Jammrock]

I get downloads of ~150-300 kbps during off hours. During high traffic hours it goes down to ~50-150 kbps. Upload speeds suck at 45 kbps max no matter when I send.

Gaming pings are at 80-120 ms for local servers during peak times. They drop as low as 45 ms during off hours.

Jammrock