 ThinkdiffPremium,MVM
join:2001-08-07
Bronx, NY
kudos:6 | Latency / Packet Loss while Uploading
High Latency to Gateway during full-speed download | 
High latency over the past few days |
If I max out my download (1.2MB/sec), there's about 20-30KB/sec upload used for ACKs. That alone is enough to bring the latency to my gateway up to 100-200ms. If I download something while using a VPN, it has to encapsulate the ACKs so it ends up sending about 50KB/sec in upload traffic. That brings the connection to it's knees - 500+ms pings and some packet loss. Webpages take forever to start loading, can't use SSH, VNC etc.
I can't recall this happening a few weeks ago. Is there anything I can do about it? Anybody else experience the same thing?
My router is very over-powered pfSense box. I also tried to bypass it just in case. Signal levels are +3.1dBmV down, 43.9dBmV up, and 36dB SNR.
--
University of Southern California - Fight On! |
|
 JabbuPremium
join:2002-03-06 | Go swap that modem. |
|
 CptGeminiInside your computerPremium
join:2004-11-29
Corpus Christi, TX
kudos:6
 ·RoadRunner Cable
| reply to Thinkdiff
I agree with Jabbu  . Also your US signal is pretty low and your DS is and SNR are fine. Do you have any splitters between your modem and the tap? If so how many. Splitters have been known to go bad too btw.
--
»www.akaskriller.com - Where your phone dreams come true! |
|
harald
join:2010-10-22
Columbus, OH
kudos:1 | reply to Thinkdiff
That's the way the protocols work. If you max out your download, all other traffic has to get in line behind the download. The same is true if you max out your upload. |
|
| said by harald:That's the way the protocols work. If you max out your download, all other traffic has to get in line behind the download. The same is true if you max out your upload.
Lol wut? Cable modems use different upstream and downstream channels and are full duplex. You can upload and download at the same time, one does not affect the other.
/M |
|
|
|
ThinkdiffPremium,MVM
join:2001-08-07
Bronx, NY
kudos:6 | reply to CptGemini
said by CptGemini:I agree with Jabbu . Also your US signal is pretty low and your DS is and SNR are fine. Do you have any splitters between your modem and the tap? If so how many. Splitters have been known to go bad too btw.
I have a single 2-way splitter. I'll try to swap it out with another one and see if anything changes.
What's involved with swapping the modem? Do I just go to a TWC store and they'll do it on the spot? What modem have they been giving out lately?
I was thinking about switching back to AT&T this month as my $29.99/month promo is up soon and I'm really reluctant to pay $53/mo for 10/1 service, so I guess I'll have to figure that out before I try the modem swap.
--
University of Southern California - Fight On! |
|
CptGeminiInside your computerPremium
join:2004-11-29
Corpus Christi, TX
kudos:6 | It depends on your area, they hand out different mode modems in all markets.
--
»www.akaskriller.com - Where your phone dreams come true! |
|
| reply to Thinkdiff
I don't think anything's wrong. Of course if you max out your download things will start to slow down; ping measures round trip time (not 1-way) and the ping response must wait in the buffer at the gateway for all the packets queued up in front of it to be sent first. If the buffer is full then it'll get dropped.
/M |
|
ThinkdiffPremium,MVM
join:2001-08-07
Bronx, NY
kudos:6 | I just used the download as an example. If I upload at half my provisioned rate (~500kb/sec), the latency also goes to hell. That doesn't seem normal to me.
The reason I posted is that it's never been this bad in the past. I've had cable service from various companies in different locations for over 10 years, and I can't recall ever seeing something like this.
--
University of Southern California - Fight On! |
|
| Mine goes up too, but I'm not sure I'd say it went to hell. It looks to me like they're just doing some "traffic management."
I just did some testing, and at 50% of my connection speed (20/2 connection so 1 meg up) it ramps up from 24ms and hits about 100ms before settling back down to ~25ms...
/M |
|
 Anonymous_AnonymousPremium
join:2004-06-21
127.0.0.1
kudos:2 | TWC does not do traffic management.
I can MAX out 30mbps using torrent on 30/5 |
|
Reviews:
 ·AT&T U-Verse
| reply to Thinkdiff
said by Thinkdiff:said by CptGemini:I agree with Jabbu . Also your US signal is pretty low and your DS is and SNR are fine. Do you have any splitters between your modem and the tap? If so how many. Splitters have been known to go bad too btw.
I have a single 2-way splitter. I'll try to swap it out with another one and see if anything changes. What's involved with swapping the modem? Do I just go to a TWC store and they'll do it on the spot? What modem have they been giving out lately? I was thinking about switching back to AT&T this month as my $29.99/month promo is up soon and I'm really reluctant to pay $53/mo for 10/1 service, so I guess I'll have to figure that out before I try the modem swap. Switch to Earthlink over TWC. I think they've got a $29.99 promo for 6 month for 10/1. |
|
harald
join:2010-10-22
Columbus, OH
kudos:1 | reply to mackey
No, not full duplex. If the protocol is TCP/IP, acknowledgements have to be sent to the transmitting server. Using downloading as an example, if you have one stream that is is receiving from a server with more capacity than the bandwidth allocated to the modem downstream, the downstream packets will back up at the CMTS, even though the protocol adjusts/waits for the acknowledgement from your computer. Works the same in the other direction. If you have one stream running and attempt to run another, such as a traceroute/ping, you will not get an accurate measurement.
Downloading is a dynamic process, with the transmitting rates continually adjusted to match the performance of the circuit. You can't measure anything accurately with more than one stream running. |
|
ThinkdiffPremium,MVM
join:2001-08-07
Bronx, NY
kudos:6 | reply to dustman81
Thanks for the suggestion. That's actually a good idea. Unfortunately, it seems Earthlink is not available where I am. Could be because our cable service is included at a bulk-rate with our normal rent payment. Unfortunately the internet service is not included, so it's subject to normal stand-alone pricing.
As for the latency, I was messing around with some traffic limiters on the router last night. I was able to download full speed and still maintain sub-30ms ping times, but I'm not yet convinced that was the fix. I'll check again tonight.
--
University of Southern California - Fight On! |
|
