Charter Spectrum → Uploading LAGS Me

Why does uploading lag my cable so bad? When I'm uploading at my cap (128kpbs), my download speeds average about 4kb/sec, where as when I'm not uploading, i get 90kb/sec. I wouldn't think uploading should effect my download speed this much, I know it doesn't affect it at all on my dsl line.

Also, when im uploading, my pings rise to above 700ms, which seems rather insane. Is all cable like this?

LAG!!! My eye!!! Time to see tech support.

90/128 is not a package sold by Charter. Check your local office to see what you're really supposed to be getting.

Here, it's 500/128 750/128 1000/128 dn/up

You'll note some lag when trying to upload and download at the same time, with any connection. But, your problems are worse than just simple lag.

Well this doesn't really surprise me, My connection doesn't slow down that bad but it does slow down a lot....and the ping times raising also is not much of a surprise but again the ping times seem a bit higher than I usually see when Uploading. If you are using 100% of your upstream though you would slow down your ping times though because your bandwidth is in use, also your downstream would be slower because of the constant two-way communication that takes place over TCP/IP and such. So if your upstream is clogged, it would take longer to initiate the downloads and such....

As far as danc694u response stating that charter doesnt offer a 90/128 Plan I think he was confused on what speeds you were talking about, from what I gather on the speeds you mentioned i would assume you are on a 768/128 plan or something about that depending on your region.. I wouldn't be too worried about your problems, its just kinda the way it works when you are using a 100% of your upstream....

said by Phatty:

---

As far as danc694u response stating that charter doesnt offer a 90/128 Plan I think he was confused .........snipped......I wouldn't be too worried about your problems, its just kinda the way it works when you are using a 100% of your upstream....

---

I wouldn't call HIS statement that he gets 90kbs down when he isn't uploading, as my being confused.

I stand by my original statement. Charter has not offered a 90kbs DL connection. That I'm aware of.

I think he's talking in kilobytes when he says 90, not kilobits, in which case he would be on the 768/128 plan.

My bad .....apologies all around

Yeah kilobytes, forgot to capitalize =). However, I just tried the same scenario at my friend's house and it works out the same. When I upload at the full cap, my downloads obviously take longer to initiate, but not only that, they average around 3KB/sec and then slowly drop to about 1KB/sec, whereas when I'm not uploading they are 90KB/sec down. I don't understand what could possibly be causing this to occur in all of our area.

Is it some kind of scheme to get people to stop uploading? The high ping times make sense, but the low speed doesn't.

This is the nature of TCP/IP. When you max out your upstream it adversley affects your downstream spectrum.

Downloaded packets must be ACKed. If your are using your full upload bandwidth, the ACKs must contend for the ability to go up. Some may not get there at all. To make matters worse, if the sender of the download actually times out waiting for for the ACK, the packet gets resent.

On the other hand...Something fishy does go on with Charter that I do not understand. When I connect to the news server with two connections, I can approach 256 kbps download speed. Logic would say there is still 3/4 meg of download bandwidth left. This does not hold true. Downloads and speed test fall to 100 kbps or less.

this is the only cable or decent highspeed option we have for under 40 bucks

techoncall, thats total bs. I have a 8mbit/1mbit dsl line, and i can be uploading at my full cap (over 100KB/sec) and still download 700KB/sec +++. It is unreasonable that when I use my all my upload speed, I have NO download speed left, I can't even load a webpage.

said by tonic:

---

techoncall, thats total bs. I have a 8mbit/1mbit dsl line, and i can be uploading at my full cap (over 100KB/sec) and still download 700KB/sec +++. It is unreasonable that when I use my all my upload speed, I have NO download speed left, I can't even load a webpage.

---

You are somewhat correct and I am somewhat correct. You are maxing out your upstream path which falls into line with what whright stated about the acks.

You are using FreeBSD Correct?

Another side/fix to this. If you're doing simple file transfers (I.E. Mp3's etc) between users. Try uploading/downloading through ICQ.

ICQ allows you to have a bit of control over the upload speed. I've found that by throttling back on upload speed, I can maintain my download speeds closer to max.

Not a complete fix. But, it does help. Using this method, I've been able to maintain some fairly good speeds both ways.

said by tonic:

---

Why does uploading lag my cable so bad? When I'm uploading at my cap (128kpbs), my download speeds average about 4kb/sec, where as when I'm not uploading, i get 90kb/sec. I wouldn't think uploading should effect my download speed this much, I know it doesn't affect it at all on my dsl line.
Also, when im uploading, my pings rise to above 700ms, which seems rather insane. Is all cable like this?

---

Hi tonic,

I ran a test where I uploaded a 4MB file using an FTP client while downloading a large file using IE at the same time. Both ran at about my capped levels with no real hit in speed.

I noticed you have 4 computers with different Operating Systems. Are they all networked on Charter and do you see the same problem on all of them. Or is this just showing up on a single machine and may be a faulty network card or specific OS?

I also have my RWIN set at 32767. Could this relate to a too small RWIN setting? Or may be the specific upload client might be causing a problem?

Kinda shooting in the dark here.:)

said by tonic:

---

Why does uploading lag my cable so bad? When I'm uploading at my cap (128kpbs), my download speeds average about 4kb/sec, where as when I'm not uploading, i get 90kb/sec. I wouldn't think uploading should effect my download speed this much, I know it doesn't affect it at all on my dsl line.

Also, when im uploading, my pings rise to above 700ms, which seems rather insane. Is all cable like this?

---

How the Upstream Cap can affect Downstream Speed
Although downstream speeds are usually high (typically in the range of 768 Kbps to 1.5 Mbps), consumer-grade Cable or DSL service often has an upstream cap (artificial limit) of 128 Kbps, which is only about 4 times faster than a V.90 (56K) dial-up modem (limited to about 31 Kbps upstream), and a fraction of the downstream speed.

What is not generally well-known is that the upstream cap can also affect the downstream speed -- if the upstream is saturated by uploading (e.g., sending a large PowerPoint file to the boss, or running a Napster or other public service), the downstream will drop to about the same speed. This is due to a weakness in the basic TCP Internet protocol, not Cable or DSL per se, and not the service provider.

Cable Internet is more vulnerable to this problem than DSL. Unlike DSL, where each subscriber has a dedicated connection to the head-end (DSLAM), the Cable Internet upstream path to the head-end (CMTS) is shared by all subscribers on a given cable segment. If that upstream gets saturated, which might be caused by only a relatively few subscribers, downstream speeds take a big drop for all subscribers on that segment

Selah

said by WolfenxXx:

---

if the upstream is saturated by uploading (e.g., sending a large PowerPoint file to the boss, or running a Napster or other public service), the downstream will drop to about the same speed.

---

Hi WolfenxXx,

I would disagree with "the downstream will drop to about the same speed". I started a large upload and download at the same time. Both the upload and download ran at about my caps. The download speed didn't drop to the upload speed.

This was run on WinXP. I also tried it on a WinME machine with the same results. However, it may be due, in part, to the improved TCP/IP stack on both WinME and WinXP.

I do agree that running Morpheus like programs can have an impact on other users with a cable connection.

Tonic is right. My downstream and many other people's falls while uploading. The reason? »cable-dsl.home.att.net/# ··· symmetry

The better cable isp's minimize this problem.

said by aaron2486:

---

Tonic is right. My downstream and many other people's falls while uploading. The reason? »cable-dsl.home.att.net/# ··· symmetry
The better cable isp's minimize this problem.

---

Hi aaron2486,

Running a download and an upload at the same time they both run right at my caps. See: »stangunncharter.net/updown.JPG

Well what do you suggest I do to fix this? How do I change my RWIN settings? Geirr...I only have one computer connected to my Cable modem, however I have another inside lan that uses my DSL for another 5 computers, wihch the FreeBSD box is also connected to, thought it uses the cable for internet, not the DSL.

I have tried throttling upload bandwidth to about 10KB/sec upload, which does increase my download to about 30-40KB/sec - but still nowhere near my cap....

said by tonic:

---

Well what do you suggest I do to fix this? How do I change my RWIN settings? Geirr...I only have one computer connected to my Cable modem, however I have another inside lan that uses my DSL for another 5 computers, wihch the FreeBSD box is also connected to, thought it uses the cable for internet, not the DSL.

I have tried throttling upload bandwidth to about 10KB/sec upload, which does increase my download to about 30-40KB/sec - but still nowhere near my cap....

---

Hi tonic,

I don't know how you change the RWIN in FreeBSD? Also, I don't know what the default is? What does this show?
»/tweaks

Could this also be a problem with the FreeBSD TCP stack?
(No flames Linux folks, I am just trying to help.:) )

You might take a look at this:
»www.freebsd.org/releases ··· nce.html

what are you tracerts and you avg ping to the first hop...

im having the same problem except worse... my downloads are at 30k a sec all the time... and ive checked the cable modem with docsdiag and my downstream cap is at 2048kpbs

i think this problem somehow relates to when charter does not upgrade the local nodes when they put in more users... they overload specific areas... so if you are out in the middle of nowhere on charter you should be able to maintain upload and download at the same time!

i would hope!

Here are my traceroutes, very fast...

[root@ts46-01-qdr2015 tonic]# traceroute yahoo.com
traceroute to yahoo.com (216.115.109.7), 64 hops max, 40 byte packets
1 10.209.0.1 (10.209.0.1) 7.458 ms 8.437 ms 11.388 ms
2 172.29.32.161 (172.29.32.161) 10.591 ms 8.972 ms 9.444 ms
3 172.29.32.2 (172.29.32.2) 10.219 ms 8.822 ms 10.214 ms
4 12.127.79.81 (12.127.79.81) 15.325 ms 15.351 ms 13.981 ms
5 gbr2-p70.st6wa.ip.att.net (12.123.44.61) 13.723 ms 14.366 ms 14.078 ms
6 gbr4-p80.st6wa.ip.att.net (12.122.5.169) 15.699 ms 15.789 ms 15.305 ms
7 ggr1-p370.st6wa.ip.att.net (12.123.44.133) 16.202 ms 18.764 ms 21.870 ms
8 att-gw.sea.level3.net (192.205.32.206) 20.481 ms 15.803 ms 19.697 ms
9 ae0-53.mp1.Seattle1.Level3.net (64.159.16.65) 16.604 ms 15.669 ms 20.397 ms
10 so-2-0-0.mp2.SanJose1.Level3.net (64.159.0.218) 31.924 ms 34.662 ms 31.182 ms
11 gige10-2.ipcolo4.SanJose1.Level3.net (64.159.2.170) 33.837 ms 35.935 ms 35.561 ms
12 * cust-int.level3.net (64.152.81.62) 33.110 ms *
13 ge-1-2-0.msr2.pao.yahoo.com (216.115.100.154) 32.913 ms ge-1-3-0.msr1.pao.yahoo.com (216.115.100.150) 33.501 ms 33.144 ms
14 vl20.bas1.snv.yahoo.com (216.115.100.225) 33.248 ms 35.543 ms vlan28.bas1-m.snv.yahoo.com (216.115.100.122) 33.926 ms
15 rc3.yahoo.com (216.115.109.7) 41.311 ms 34.582 ms 37.154 ms

I can't really do the tweak test until I get my new monitor for Xwin, because links/lynx dont support java...

Does anyone know how to check RWIN settings in FreeBSD?

said by tonic:

---

I can't really do the tweak test until I get my new monitor for Xwin, because links/lynx dont support java...
Does anyone know how to check RWIN settings in FreeBSD?

---

Can you use this site?

»forums.speedguide.net/cg ··· optd.cgi

Doesn't seem to be working =(.

Check here for my pings:
»monitor.dslreports.com/m ··· .207.223

Notice the long term, where the pings spiked up to the max for a day or so...this is where I was uploading at my cap...The actual pings during this time were above 2,000ms just to first hop.

Hi tonic,

I see another user, R_Kelly, in Yakima, WA also posted about the problems in your area. Hopefully, everyone is opening Trouble Tickets on the issue?

Sorry you are having those problems with your connection.

Actually, I tried to call and ask about this, but the tech support people you get to talk to don't even seem to know what a ping is, and especially not the upload speeds or anything like that in our area. When I ask for a higher level of tech support, they just question my motives and basically won't let me. Tech support here in Washington seems rather incompetant (spelling) if you ask me.