Okay, this is almost embarrassing (since I used to work as the default tech support guy in the lab that I was formerly employed in), but I need some tech help with my internet connection.

Description of the problem/The symptoms:

I can't send files using my browser. That means I can't attach files of any kind to my e-mails or upload pictures to image-hosting services, and even posting text replies on message boards take several minutes. I have no problem receiving files via my browser from external servers, however. I've been able to successfully upload files less than 10 kB in size but anything bigger than that results in a "server timed out" message (it takes too long to transmit the file apparently. Everything else seems to be working normally. On one occasion, I received an invalid XML prompt while accessing Yahoo!, but I think that was just a coincidence and has nothing to do with the issue at hand. 

As you can imagine, this is terribly frustrating.

My PC's relevant specifications

- processor: AMD Athlon 64 (AMD Sempron 3100+ running at 1.8 Ghz with a 9.0x multiplier)
- motherboard: K8MC51G with Phoenix BIOS (version 6.00 PG)
- RAM: 736 Mb DDR-SDRAM
- networking controller: NVIDIA nForce networking controller
- installed OS: Windows XP SP2
- Browser: Firefox
- Firewall software: Comodo Firewall Pro
- Antivirus software: Avira Antivir

Solutions I've tried so far, but ultimately did not work (although not necessarily in the order listed):

- Checked for viruses, trojans, and other malware that might be diverting resources (none detected)
- cleared my browser cache
- used alternative browsers besides Firefox (Opera, Internet Explorer)
- tested other e-mail and file-hosting sites (besides Yahoo! mail, the problem also persists in Gmail, Hotmail, Photobucket, ImageShack, and YouSendIt)
- defragged my hard drive
- re-set my WinSock settings using WinsockXP Fix
- Tested and optimized my connection using the proprietary diagnostic tools provided by my ISP
- checked my motherboard's built-in ethernet connection (connected at 100 Mbp/s, sent and received packet ratio is normal at around 1:1)
- connecting to the internet with my software firewall disabled
- connecting to the internet with my anti-virus software disabled
- connecting directly to the cable modem, bypassing the router
- manually re-setting the cable modem (i.e., turning it off, and then turning it on)
- manually re-setting the router
- used two different PCs besides my own (an older Pentium III with Windows XP SP1 and a newer Windows Vista machine) to access the internet using my connection, and they experienced similar problems)
- and finally, calling tech support. I ran down the same list with them (and the guy was sort of embarrassed to say that he didn't even know what WinsockXP fix does) and they're stumped. From their end, everything about my internet connection looks normal. The senior tech support guy even left me his contact info and asked me to call him if and when I solve this particular problem, so they can use any solution for future reference.

So, anybody got anything?     

A very interesting problem.  And kudos on very thorough checking.  A couple quick questions;  when you checked with other PC's, how were they connected? (to router, or directly to modem)  Have you checked it with different protocols (ftp, utp, etc.), to see if it's a port issue?

Just going off of what you've checked, it sounds as if you've narrowed it down to the cable modem, or further back.  It's unlikely the cable is the culprit, but a quick swap couldn't hurt.  I'd lay even money it's the modem.  You might want to see what kind of indications you get from bandwidth testing, such as this page does.  Whether it pings all the way through to the PC, or just to the modem, I'm not exactly sure.  If you have a service contract with the cable company, you can always have them come out & swap it, as you having the problem on multiple PC's pretty much points the finger at them.

(resetting power & swap-tronics are the two easiest, and most reliable, ways of narrowing down/solving most problems  :thumbup:)

I'd agree that the one non-variable seems like the modem (or the cable service itself), since you've shutdown/swapped out/reset everything else. Trying another modem, or trying your modem at another location, might pin it down.
But weird problem, nontheless. 

Quote from: Panther_Gunn on February 05, 2008, 03:01:37 AM
A very interesting problem.  And kudos on very thorough checking.  A couple quick questions;  when you checked with other PC's, how were they connected? (to router, or directly to modem)  Have you checked it with different protocols (ftp, utp, etc.), to see if it's a port issue?

I'm beginning to suspect as much. I can download fine via FTP (4 Mb in less than half a minute), but uploading stops after I've transmitted around 20 Kb.

QuoteJust going off of what you've checked, it sounds as if you've narrowed it down to the cable modem, or further back.  It's unlikely the cable is the culprit, but a quick swap couldn't hurt.  I'd lay even money it's the modem.  You might want to see what kind of indications you get from bandwidth testing, such as this page does.  Whether it pings all the way through to the PC, or just to the modem, I'm not exactly sure.

I think that test just pings to the PC. In any event, I can complete the first half of the test (where it tests download speed) but I can't get through the upload portion of the test... pretty much confirms what I've already seen with the two different protocols.

Quote from: Panther_Gunn on February 05, 2008, 03:01:37 AM
If you have a service contract with the cable company, you can always have them come out & swap it, as you having the problem on multiple PC's pretty much points the finger at them.

Quote from: tommyboyI'd agree that the one non-variable seems like the modem (or the cable service itself), since you've shutdown/swapped out/reset everything else

Convincing the ISP that the problem is on their end might be the toughest solution of all :lol: The kid who took my call in tech support kept insisting that everything should be fine because there wasn't any large discrepancy between the upload/download numbers that he could see... but the numbers are apt to approach equal (and be misleading in that way) if the PC's been connected to the internet for a while. I'm pretty much convinced that the cable modem is the problem... it's around 5 years old, and we had a recent power outage followed by a surge that could have easily overwhelmed my dinky surge protector. Anyways, I'll call tech support again later today and try pleading with them to send a knowledgeable person (somebody who actually knows what they're doing) out to test the modem (instead of just looking at upload/download ratios ont heir screen).

The modem's ul/dl ratio can be misleading, depending on what they're looking at.  They need to make sure they can see the numbers for the ethernet port, not just raw numbers (or the coax port).  And looking at stored info may not be the best way, but some kind of active ping, preferably from them to the MAC address of your ethernet adapter.

A surge may have effected something on the upload portion of the ethernet port, and *may* be fixable if they can force the modem's programming back to factory default.  If you haven't already done so in previous testing, disconnect the power cable from the modem and the wall completely, and leave it powered down for 10-30 minutes before trying again (I actually had a PC power issue that didn't go away until *both* ends of the cord were disconnected at the same time.....one at a time didn't do it.  makes no sense, but it worked).

If the problem is just FTP and just related to uploads, I don't think it would be a hardware problem with the cable modem.  You'd likely see a lot more issues than just FTP upload.  It could easily be something your ISP is doing, though.

Glitches are always possible, though.  To rule that out, I'd power down, reseat all of the internet connections, and power everything back up starting with the cable modem and working your way back to the PC.

I've seen a similar issue with FTP interactions in the past, but the fact that you've used multiple PC's to connect would seem to rule that out.

What kind of cable modem do you have?

It sounded like there was trouble with non-FTP uploads as well. That is all uploading is experiencing trouble.

My guess would be a cable modem issue at this point. Some sort of bad connection with cabling is possible, but doesn't seem very likely to me.

Quote from: stumpy on February 05, 2008, 10:00:48 AM
It sounded like there was trouble with non-FTP uploads as well. That is all uploading is experiencing trouble.

My guess would be a cable modem issue at this point. Some sort of bad connection with cabling is possible, but doesn't seem very likely to me.

Wouldn't hurt to have the provider replace it, but I have a feeling it won't help.  It sounds more like an upstream issue.

Quote from: BlueBard on February 05, 2008, 06:59:43 AM
If the problem is just FTP and just related to uploads, I don't think it would be a hardware problem with the cable modem...

... What kind of cable modem do you have?

It's one of the earlier Motorolas. I can't see the model number from where I am right now (the modem's in the deep dark recesses behind my desk) but it's one of the earliest models sold in Canada (I think it's from 1998 or something), the ones that didn't come with a power button (so re-setting means pulling the power adapter from the wall socket  :lol:). Oh, and it's not just an FTP problem, it occurs with all uploading via any protocol (http, ftp, utp).

Quote from: Panther_Gunn on February 05, 2008, 05:03:35 AM
The modem's ul/dl ratio can be misleading, depending on what they're looking at.  They need to make sure they can see the numbers for the ethernet port, not just raw numbers (or the coax port).  And looking at stored info may not be the best way, but some kind of active ping, preferably from them to the MAC address of your ethernet adapter.

Quote from: stumpy on February 05, 2008, 10:00:48 AM
My guess would be a cable modem issue at this point. Some sort of bad connection with cabling is possible, but doesn't seem very likely to me.

Well, finally got through to a techie peer in tech support. Asked him to do an active ping, check for related issues in the area, all the other things you guys mentioned and things I thought of the rest of the day... and he did come up with a couple of issues, all of which could be traced either to the cable modem itself, or higher up the line (with the cabling)... it looks like I might not be the only one experiencing the same problem in the vicinity, but no other customer's alerted them to it yet (I guess I'm the only person in my block who routinely sends files larger than 10-15 Kb). It could all be related to the crap weather (snow alternating with freezing rain) we've been having causing all sorts of power disruptions. I've never heard of a coax problem affecting solely the uploading, though, but I guess it happens. They'll be sending a technician to check the hardware by Wednesday, and hopefully, this long, national nightmare will be behind us all  :lol: Thanks for all the input and insights guys.

Woo-hoo! Finally back up and working. The tech ended up replacing the cable modem... he never really did pin down what exactly was wrong with it, he just chalked it up to the thing's age.

Good on you. And, I'm glad you posted the follow-up resolution, as I was wondering where the problem would turn out to be. :)