ADSL download Errors

[Fluff]

Hi

I have ADSL 1Mb broadband and have recently switched to another package with the same provider.

Suddenly I am getting a very high number of "errors" showing up in the Broadband status window under Activity - Received - Errors.

Typically 15 minutes surfing generates literally hundreds of errors in the downloads display while the uploads is completely error free.

My phone company say the line is good and its an ISP issue.

My ISP tech support (Tiscali) say speed is good and to ignore these errors :confused:

Any ideas please on what is causing these errors as re-installing the modem and connection software has made no difference.

[mjc]

What exactly are the errors...can you be a bit more specific?

[Fluff]

The "status" window ( launched by clicking the taskbar icon bottom right that shows Internet connection active) just displays counters not error messages unfortunately so its hard to diagnose the problems

Counters displayed (general tab) include status, duration, speed and under "activity, counters for bytes sent, received, compression and errors but not the cause.

I wish I could be more specific but its a tough one :confused:

[mjc]

That is usually for things like transmission errors, retrys, etc...

What exactly is your setup?

Yes, ADSL but...is a USB modem, one that connects to a NIC...some other sort of connection. What about network properties? Have you done any kind of connection 'tweaking'?

What version of Windows?

It almost sounds like too low of an MTU or RWIN value...but without knowing it is hard to say.

[Fluff]

I'm running Windoze XP Pro / SP2 on an AMD 2600 PC.

For Internet access I use the ISP supplied Alcatel/Thomson 330 Speedtouch external USB modem (USB powered). The drivers supplied are the latest version so no probs there.

Currently using the default settings so no tweaks as yet.

What worries me is that TCP protocols guarantee delivery using PAR (positive acknowledgement and retransmission in the event of errors).

I'm wondering, if data is being repeatedly re-sent whether this could consume that precious commodity "Bandwidth" (that we can never get enough of :p )

[mjc]

Retransmissions do soak up your bandwidth...

The USB modems are more error prone than ethernet based ones.

XP by default should be fine for most cases and tweaking shouldn't be needed...but there is always the chance that your ISP is not using the standard settings and what not. But I think the big thing right now is the USB modem, which tends to be more error prone.

[Variable]

transimission errors don't necessarily mean anything. That is why TCP exists, to deal with transmission errors :p

Usually transmission errors are caused by EM interference or bad cables. I would make sure your lines are not near any spinning motors or power cables. Incoming and outgoing packets travel down two different wire pairs inside your cables... It is probably not your ISP having issues ... You could also have a hardware firewall sitting there causing issues by looking at to many things and not handling them smoothly.

You send thousands of packets during a connection. As long as your DSL speed is showing fine there is really nothing to worry about.

[Fluff]

Thanks for the feedback guys - most welcome as my ISP and Telecom company continue to play pass the buck back and fore with no attempt to even investigate.

I'm going to try and borrow a non USB modem and see if this helps as there are no EMI problems with the cables here.

Yesterday was especially bad registering over 1000 errors in less than an hour online, something I never had with my previous ADSL package.

Well done Tiscali - yet another leaky pipe :D

[Fluff]

****UPDATE***** hope this helps others with similar problem

After trying just about everything my ISP Support suggested, I finally managed to get them to send me a replacement modem (Sagem 800 USB) to try.

I uninstalled the Speedtouch330 USB modem, installed the new one with drivers and :) :) :)

Not one single error in the last 8 hours surfing yippee :)

The speed increase is quite apparent now, proving my point that TCP in demanding resending of packets is consuming bandwidth and slowing your connection to an obvious degree

;)

[mjc]

That's good to here...so it was the modem after all.

And, yes, the errors may have had an impact, but with what it looked like you were getting that impact should not have been very, if at all, noticeable. So there was more to it than what was being reported...or something that wasn't being reported, like a problem witht the modem itself, was having an impact on your speed.

[Fluff]

I think youre right about the modem. ;)

I did use the Speedtouch 330 diagnostics software just before uninstalling it.

On the AAL tab, I noticed there were a high number of SDU Length errors, similar to those in my Broadband status window.

I dont know much about SDU's other than they are service datagram units - does this point to packet/frame encapsulation errors within the USB modem anyone know ??