My downloads have become completely erratic with my high speed cable connection. Some are almost immediate while others are as slow as dial-up. It happens with different browsers and different versions of linux. Is there anything in the computer itself that can use this problem or can I be sure that it is a ISP problem?

Well there are tons of things that can cause problems.

1. Do you have a router (more than 1 computer connected)?
2. What kind of downloads?
3. Do you host a server through your connection?
4. Can you monitor your traffic (in and out)?
5. Any Windows machines? Could be a virus.

Possible causes:

1. Your outgoing bandwidth is saturated (Your sending more data than your ISP allows) This can slow your downloads by delaying Ack packets
2. Your router can not handle the number of connections (often a problem with torrents)
3. Your ISP is throttling your connection
4. Your ISP caches popular downloads
5. Cable modems share bandwidth with all connections in an area, that area could be over subscribed.
6. The site you are downloading from could have inadequate bandwidth.
7. A bad nic or driver can cause these problems.
8. A bad signal level to your cable modem


So the answer is, it could be your computer, drivers, router cable modem cable connection, ISP, the internet, the site you are downloading from.

If I were you I would start with your router and cable modem as they are the most likely problems.

Most cable modems have a web server you can access to get information about signal strength, logs . . . motorola Surf Boards use http://192.168.100.1 (if you have a router it may prevent connecting to the cable modem web server, your ISP can disable the web server.

Check the Cable modems logs first do they reveal problems?

In linux you can monitor traffic with TCPDUMP, check man pages for details. This can help you determine where to look next.

While I appreciate never say never for this detailed response, none of his suggestions apply, e.g. I am using a wire connection not wireless.

My reply applies equally to wired and wireless connections (to a router). I didn't address wireless problems at all.

I think you are going to have to provide a lot more details about your problem to get some help.

1. Cable Company
2. Cable Modem Brand and Model
3. Type and size of downloads giving you trouble (FTP, HTTP, Torrent, ...)
4. Model of NIC (Network Interface Card)
5. Driver used
6. does it happen more often at a specific time of day?
7. Tell us what you have tried to solve the problem.
8. Is more than one computer connected to the cable modem? If yes information about the router.

There is one other thing you can do to try to narrow things down without having to dig too deep yourself. This may or may not reveal the problems, but it is worth a shot.

Try the following tests from this site:
http://www.dslreports.com/tools


Speed Tests
Tweak Test
Line Quality Testing

(free membership necessary to run the following)
Smokeping
Doctor Ping

These may reveal the problem if it is a network problem. Save the results of these test if they show problems and post them to their forums or here to get help on where to go next.

Disclaimer: I am not affiliated with DSL Reports, though I frequently use their services to diagnose intermittent problems.

Good Luck!

1. Cable company cox
2. Cable modem scientific atlanta 2100
3. http
6. happens all the time
7. had cox technician check
8. Netgear WGR 614 - only using wire connection for one computer

Can't answer 4 and 5

Speed down ~5 Mbps, up ~2.5 Mbps
Tweak - Good data stream

Well evidently your cable modem does not have a web page to check it's status. I have friends that have had Cox, and had problems, but there is no proof to be had if you can't check signal strengths . . .

So lets move on to checking your system.

as root (or using sudo) at a command prompt enter the command ifconfig

We are interested in the Bold output above. Are there any errors, dropped packets or overruns?

If that doesn't turn up anything, then your nic and driver are probably OK, so try:

Using several different websites. This may reveal a bad router or something causing a problem.

Anyway if you haven't already, I would use the tools I mentioned at dslreports.com especially the Line Quality Testing, and the Smokeping tests. If there is a problem it should show up in one of these tests.

Finally, I noticed that while you are connected via a wire you are using a wireless router. It is possible that the wireless router is not properly secured and that people are leaching off of your internet connection, that could certainly cause the problems you are having. You might try making sure the wireless router is secured with a strong KEY and WPA encryption.

eth0 Link encap:Ethernet HWaddr 00:1c:25:69:10:58
inet addr:192.168.10.2 Bcast:192.168.10.255 Mask:255.255.255.0
inet6 addr: fe80::21c:25ff:fe69:1058/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:43919 errors:0 dropped:0 overruns:0 frame:0
TX packets:46554 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:35782029 (34.1 MiB) TX bytes:10972538 (10.4 MiB)
Interrupt:220 Base address:0x6000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:160 errors:0 dropped:0 overruns:0 frame:0
TX packets:160 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:11252 (10.9 KiB) TX bytes:11252 (10.9 KiB)

traceroute to www.nytimes.com (199.239.136.200), 30 hops max, 40 byte packets
1 ip24-251-166-226.ph.ph.cox.net (24.251.166.226) 11.177 ms 11.408 ms 11.688 ms
2 10.84.64.1 (10.84.64.1) 35.561 ms 36.217 ms 36.509 ms
3 ip68-2-4-9.ph.ph.cox.net (68.2.4.9) 36.750 ms 36.980 ms 37.209 ms
4 70.169.73.37 (70.169.73.37) 61.206 ms 61.880 ms 62.181 ms
5 paltbbrj01-so000.0.r2.pt.cox.net (68.1.2.157) 64.655 ms 65.238 ms 65.531 ms
6 ae-1.r20.snjsca04.us.bb.gin.ntt.net (129.250.5.33) 66.630 ms 35.958 ms 50.486 ms
7 as-1.r21.chcgil09.us.bb.gin.ntt.net (129.250.3.76) 91.684 ms 91.930 ms 91.286 ms
8 ae-0.r20.chcgil09.us.bb.gin.ntt.net (129.250.3.97) 87.208 ms 86.588 ms 90.460 ms
9 as-1.r21.nycmny01.us.bb.gin.ntt.net (129.250.6.14) 110.774 ms 111.706 ms 111.349 ms
10 * po-3.r02.nycmny01.us.bb.gin.ntt.net (129.250.2.41) 115.488 ms 117.278 ms
11 ge-1-1.a00.nycmny01.us.da.verio.net (129.250.30.113) 115.990 ms ge-1-2.a00.nycmny01.us.da.verio.net (129.250.30.193) 113.636 ms ge-1-1.a00.nycmny01.us.da.verio.net (129.250.30.113) 114.751 ms
12 * * *

traceroute to www.mail.yahoo.com (68.180.206.184), 30 hops max, 40 byte packets
1 ip24-251-166-226.ph.ph.cox.net (24.251.166.226) 11.131 ms 11.356 ms 11.582 ms
2 10.84.64.1 (10.84.64.1) 22.048 ms 22.573 ms 26.898 ms
3 ip68-2-4-9.ph.ph.cox.net (68.2.4.9) 27.502 ms 27.828 ms 28.079 ms
4 70.169.76.229 (70.169.76.229) 29.023 ms 29.625 ms 29.917 ms
5 langbbr01-ae0.r2.la.cox.net (68.1.0.232) 42.335 ms 52.695 ms 41.726 ms
6 so-3-0-0.pat2.sjc.yahoo.com (216.115.96.46) 50.468 ms 51.512 ms 42.586 ms
7 ae1-p161.msr1.sp1.yahoo.com (216.115.107.63) 43.749 ms ae0-p161.msr1.sp1.yahoo.com (216.115.107.59) 43.166 ms ae0-p171.msr2.sp1.yahoo.com (216.115.107.83) 43.428 ms
8 te-9-1.bas-a2.sp1.yahoo.com (209.131.32.23) 49.651 ms te-8-1.bas-a2.sp1.yahoo.com (209.131.32.19) 49.949 ms te-8-1.bas-a1.sp1.yahoo.com (209.131.32.17) 48.967 ms

traceroute to www.weather.com (63.111.69.121), 30 hops max, 40 byte packets
1 ip24-251-166-226.ph.ph.cox.net (24.251.166.226) 11.222 ms 11.463 ms 11.693 ms
2 10.84.64.1 (10.84.64.1) 20.692 ms 21.279 ms 21.568 ms
3 ip68-2-4-9.ph.ph.cox.net (68.2.4.9) 137.954 ms 138.528 ms 138.822 ms
4 72.214.144.69 (72.214.144.69) 23.459 ms 23.989 ms 27.666 ms
5 chnddsrj01-so010.90.rd.ph.cox.net (68.2.15.1) 28.315 ms 28.901 ms 29.192 ms
6 ae-11-11.car2.Phoenix1.Level3.net (4.69.133.34) 115.656 ms 64.243 ms 64.730 ms
7 ae-4-4.ebr2.LosAngeles1.Level3.net (4.69.133.38) 37.105 ms 37.350 ms 37.585 ms
8 ae-2-70.edge1.LosAngeles9.Level3.net (4.69.144.74) 34.216 ms ae-1-60.edge1.LosAngeles9.Level3.net (4.69.144.10) 34.898 ms ae-2-70.edge1.LosAngeles9.Level3.net (4.69.144.74) 35.724 ms
9 verio-level3-10ge.SanJose1.Level3.net (4.68.111.250) 35.946 ms 36.167 ms 35.103 ms
10 0.ge-7-2-0.XL4.LAX15.ALTER.NET (152.63.116.162) 35.351 ms 29.057 ms 28.448 ms
11 0.ge-5-2-0.XT2.ATL5.ALTER.NET (152.63.81.6) 73.105 ms 72.803 ms 71.790 ms
12 POS5-0.UR1.ATL7.customer.alter.net (157.130.80.14) 72.417 ms 74.305 ms 74.570 ms
13 198.5.128.138 (198.5.128.138) 73.600 ms 198.5.128.130 (198.5.128.130) 77.847 ms 78.375 ms

I don't think the problem is with your Computer hardware. Though it doesn't look like your computer had been up very long.

Are you sure that your WGR 614 router is configured for secure wireless and that no one is using it??? (Frankly, this is what I am leaning toward)

The only other thing that comes to mind is that if your DNS responses are slow, that can cause some sites to load painfully slow (sites that load images from a lot of different servers), and others to load more quickly (sites that load everything from the same server).

Open a command prompt and type

Again try several websites. You should find a line like this:

that time should be low, if it is high there could be a problem.

Look for a line like this too:

That should be your COX DNS server, if it is not it may be causing a delay.

All query times are much longer than your example. All Servers are the same.


www.amazon.com. 42 IN A 72.21.210.250

;; Query time: 53 msec
;; SERVER: 208.67.222.222#53(208.67.222.222)

www.marketwatch.com. 76 IN CNAME marketwatchus.wsj.akadns.net.
marketwatchus.wsj.akadns.net. 98 IN A 205.203.131.32

;; Query time: 53 msec
;; SERVER: 208.67.222.222#53(208.67.222.222)

www.washingtonpost.com.akadns.net. 14 IN A 12.129.147.65

;; Query time: 48 msec
;; SERVER: 208.67.222.222#53(208.67.222.222)
;; WHEN: Tue Nov 3 08:10:04 2009


www.allcarselectric.com. 300 IN CNAME allcarselectric.com.
allcarselectric.com. 300 IN A 69.20.62.205

;; Query time: 90 msec
;; SERVER: 208.67.222.222#53(208.67.222.222)


www.nytimes.com. 35 IN A 170.149.173.130

;; Query time: 65 msec
;; SERVER: 208.67.222.222#53(208.67.222.222)

Yes, your query times would be longer. Since I am at work right now I am connected to fiber and one hop from a major net backbone router in Chicago, you have to snake your way through Cox Cable and then to OpenDNS servers to get a response.

The only one that was really on the long side was 90ms and that is not outrageous given the pings from your traceroutes.

So we are back down to your WGR 614 router. Are you sure the Wireless on the router is properly secured and no one is using it?

If you have a firewall configured on your computer you might try turning off the cable modem and powering down the computer, disconnecting the WGR 614 router, and connecting the computer directly to the cable modem. Then turn on the computer and cable modem.

If the problem goes away it is the WGR 614 router, and it is probably not properly configured and someone is probably using it to leach your internet connection.

The only other thing that is a little suspect to me is your outgoing volume, compared to your incoming volume, but without knowing the time period that happened over, it is hard to tell if that is a problem.

Your outgoing is almost 1/3 of your incoming and that could be pushing the limits of your bandwidth, that would cause the problems you describe.

You aren't running any P2P software or torrent software right?

It seems to me that a while back I did disconnect the router and had the same problem, but I could try again. Given the nature of this community, I doubt that anybody could be tapping into my signal, especially during the day when virtually nobody is home. As far as I know I am not using P2P software or torrent software.

For the record, until this started when I had guests we could operate two wireless computers and my desktop all at high speed. Supposedly Cox has been working on their equipment around here for quite a while but I know no details.

I just tried dig on my Asus laptop wireless. The speeds were:

Amazon Asus 61 Desktop 37
Marketwatch Asus 41 Desktop 40

I must thank you again for all the trouble that you have taken on my behalf.

You might be surprised about people tapping into your wireless, and if they are doing P2P or torrents they wouldn't need to be home, just leave their computer on and connected to you. If they get caught, then they say, it was an accident.

From my office I have access to at least 30 different wireless access points, many unsecured. From home (I live in the country) I still have access to 4 - 7 depending on weather and where I am in my house and mine is the only one that is secured.

If the problem persists when your computer is connected directly to the cable modem, and you aren't running any P2P or torrent stuff, then I would say it is likely a Cox problem.

Again if you haven't already I would check out the tests I mentioned that are available on DSLReports.com. At least one of the tests runs over a 24 hour period and that can be really telling too.

They can go a long way toward finding problems like these and if you keep the reports and show them to the Cox tech you may get a different answer, if you get one that understands networking and not just cable.

Frankly most of the techs just check to make sure the signal levels are good and don't even have a clue how the internet works. Many service techs are not even aware of network issues that they may be having when they are answering service calls such as yours.

Well "never say never", I owe you an apology. I connected my computer directly to my cable modem and everything is working as it should.

This leaves me with a problem for when I have guests I need the wireless signal for them. Other than adding security to my router (which I will need to learn how to do) is there any way to be sure that my problem is outside interference and not a defect in my router?

No problem, just bump up my Thanks! ;^)

I am not familiar with that particular router, but most wireless routers will show you the MAC address (Hardware ID) of the connected equipment. That won't tell you who, but it will show the connection.

You can find instructions for you router here (there are several versions and I don't know which one is correct for you).

http://kb.netgear.com/app/products/family/a_id/1296

I did read yours is not intuitive to secure and the setup doesn't even tell you to set a key, so it might be worth it to spend a few bucks on a newer model. You will definitely want to do that if it doesn't have WPA or WPA2 security as I describe below.

Set up your router for WPA2 if possible or WPA at a minimum security.

Make sure you set the SSID to something distinctive and I normally include the word private so no one can say they thought it was public.

When you set the key make sure it is at least 12 characters long and contains some special characters. (The key is what prevents others from accessing it.)

Then you will just need to give your guests your SSID and Key.

A good key that is easy to remember might be:

JQPublic-123ABCRoad=Full@cce$$


Good Luck!