Cable Modem Primetime Slowdown - Myth or Reality? 43
The Llama King asks: "SBC (SWBell, Pacbell, etc.) is whacking away at Time Warner cable in our area, running DSL ads that make fun of prime-time cable modem slowdown. And Time Warner-Houston/RoadRunner does seem to be having a problem in the past month with nasty ping times between 8 pm - midnight Central time (traces submitted to internal RoadRunner news groups show the problem appears to be a pair of routers at the gateway to one of several backbones). While this problem is recent, it begs the question - are prime-time cable slowdowns real or a myth? Can a well-configured cable modem network avoid the congestion SBC pokes fun at in their commercials, or is it inevitable? What are Slashdot users seeing?"
I don't notice much slowdown (Score:2, Informative)
Comcast/Planetcable -- Mercersburg, PA (Score:2, Insightful)
In general though, I have noticed a substantial variation in the quality of service from day to day, and month to month. Some days or weeks at a time it's fine, and other times it's horrible (high ping/high packet loss) for months.
Little bit of each (Score:3, Interesting)
Ameritech is running the same types of ads here in Ohio as well. What the ads don't say clearly is that you need to live next door to the central office if you want the maximum DSL bandwidth. For me, where I live nearly 3 miles from the CO, the best they claim for me is 128Mbps either direction. All that for $50 a month.
By contrast, the cable can handle huge amounts of bandwidth down and I'm pretty much assured a minimum of 128Kbps up. But, the cable bandwidth is shared among all my neighbors. It's important to realize, though, that all my neighbors aren't sharing 1.5Mbps down and 128Kbps up. It's more like 10.5Mbps down and 512Kpbs up. Business customers can get a dedicated line that gives them the entire bandwidth. Heck, Road Runner Columbus [rrcol.com] even offers what they call a "direct connection" to the internet at up to 45Mbps symetric.
Back to this topic, have I ever experienced a slow-down during peak hours? Nope. But I now live in a subdivision that I am certain isn't abusing the cable network. When I lived near Ohio State, however, I did find at times I was limited in bandwidth and Time Warner had troubles with their DHCP server getting overloaded. The worst data rate I ever was able to receive was somewhere near 500Kbps. That's many times better than most DSL lines. And at $45 a month (new price "adjustment"), it's easily the better choice.
Re:Little bit of each (Score:5, Funny)
Damm, there's that "post from the future" bug again.
Re:Little bit of each (Score:2)
DSL is the same price, with a optimal maximum download speed of 768 kb/s. If I lose 3/4 of my cable performance, I'm still downloading way the hell faster than I would be on DSL. Additionally, with Shaw, the upload speed isn't capped (or rather, if it is, it's capped at a high enough level not to inconvenience any who aren't trying to be an Akamai peer.
I do think that I'll be forgetting DSL, when my downloads with cable peak out at double the speed of a dedicated T1. Obviously the bandwidth restrictions aren't at my ISP's end.
Re:Little bit of each (Score:2)
I lived outside DSL's range, then one day, I saw the telco guys working about 50 feet from my door. After they had been there all day, I went and asked them if I should expecet a loss of telephone service(I knew I wouldn't but I was fishing)
they told me there were installing hardware to get DSL to the people who where currently out of range.
The next day I ordered DSL, 768/128 39.95. that was sweet.
then the telco decided they could provide the service for more money and get all the customers simple by jacking the line rate up for all the DSL providers.
After which I went to cable. I was the only one on my node, and I was getting 9Mbp. I miss that.
Re:Little bit of each (Score:2)
Ameritech is running the same types of ads here in Ohio as well.
Since Ameritech is owned by SBC, they're probably the exact same ads.
Charter In Auburn, MA (Score:3, Informative)
@Home in Canada (Score:1)
yeah it does get slow, really slow.
there are times in the summer where having a dial up will be faster (I'm not joking!)
over all it's not that bad though
Not slow, but bursty... (Score:2, Interesting)
TWC/RR Orlando FL (Score:1)
Like most people here my ping times varied greatly. My set of test pings to local ISPs and to internic.net would go from 15ms to 300ms and back in a matter of 10 minutes. I actually see the worst performance during the business day.
The techs said that this big AT+T building next door was using RR for business purposes so maybe that was the cause.
I've never had 'poor' performance, I've always been happy with it. I've certainly never seen it slow down to near-dialup speeds like some have mentioned.
Cable slowdown....not entire myth but not all true (Score:3, Interesting)
I agree with the other person about the DSL ads and the fact that you have to be practically ontop of the CO to get the high speeds. I am only 1 mile away and I couldn't even get 128 K a while ago. Now I can get it, but it's all slower then and more expensive then my cable modem. Lately, Road Runner has been REAL attentavie to outages even. I remember one time I was out for a whole day and I didn't even call techsup and I had a credit on my bill the next month. That's cool. They KNOW when these outages happen. You should not have to call and bitch to get a credit. I do know that they are starting to be more attentive to customers, although their network issue page is usually out of date. At least they are updating the equipment gradually. I used to have a legacy modem, but after one REAL long outage, they gave me a new DOCSIS modem. Plus I think that some cable providers are loosening the IP restricitons and not hassling people who want to share their connection with other machines. Cable Modems are getting better. They have to or they are going to really loose it when the local phone companies get a clue about DSL and reduce price and make it competitive and make it so you don't have to live over the CO to get a high speed connection.
It's real (Score:2, Informative)
Not bandwidth, DNS (Score:1)
I, personally, have not noticed a slowdown during peak hours, and I'm in a neighborhood where it should matter.
If you're trying to decide on whether to go DSL or not, consider that RR (at least around me) won't do static IP (not even one). There are some vague workarounds that'll let me ID and use my IP for something that talks to the outside world, but that's not really the route I want to take.
Re:Not bandwidth, DNS (Score:1)
note: you can use any DNS server. the closer ones are usually faster, but if they are unstable, change them
Re:Not bandwidth, DNS (Score:2, Informative)
#1, even if it works now, they may update their configuration to exclude people who are not users of their network from running queries on the internet at large with their servers. Its not that hard to configure it that way, and its an easy way to reduce network usage.
#2, if there is any problem with that server, it may be difficult to resolve
an easier/more reliable step to take is make your own caching server that will go ahead and hit the root-servers for pointers if your isp's aren't working
Re:Not bandwidth, DNS (Score:1)
Just as an FYI, RR doesn't use static DNS, but dynamic on their side, so maybe that's part of it. Personally, you start talking networking, and I'm already asleep.
I'll second that (Score:1)
Any internet technology can be oversubscribed (Score:5, Informative)
With a cable modem, the only difference is that the very first hop might also be oversubscribed.
A cable has a lot of bandwidth. That bandwidth is divided up into channels (on an NTSC analog system, channels are all 6Mhz wide, your channels may vary). Each internet cable box is assigned a channel (or set of channels, if channels only come in one size). Your next door neighbor's cable box might use a different channel, and thus not be in the same neighborhood.
Logically, a cable system is a tree, or set of trees, with the root of each tree at the cable company office, and the customers are the leaves. The thicker branches may run on fiber, they support more channels, and therefore more neighborhoods.
A wee tiny cable company may have a single T1 (1.5Mbps) line connecting to the greater internet, a large company might have several OC48 (2.5Gbps). The same is true for DSL providers.
ISP's either charge premium rates or they oversubscribe the service, or both. I don't see a primetime slowdown on my $180/month, 384K DSL line.
Re:Any internet technology can be oversubscribed (Score:1)
Your first hop is always your headend. From the headend it switches off the cable system onto a larger pipe than cable. The prime-time slowdown is no different in nature than DSL.
DSL, from my experiance, suffers much larger slowdowns due to chronic oversubscription and bandwidth caps to the customer. Unlike DSL, the cable company can slap a headend in pretty much anywhere they can get permission to slap in a box the size of a shrubbery, and can put more than one node in the same physical connection if they've got fat pipes (larger than cable) going to the outlying headends.
The first hop is always just one customer.
Not for me. (Score:2)
But, all bandwidth can be oversold, not just cable. My friend had DSL in Texas and the telco oversold the local bandwidth and his pings went to 500ms just to his first hop at the ISP. At some point ALL bandwidth is shared, it just happens that DSL users have a piece of wire to the CO...but at the CO it all comes together, just like a loop on a cable modem.\
Marketing hype....
It's true (Score:1)
You can run into congestion no matter what type of access you use, the disadvantage of a cable inet access is you can also have congestion problems on the local loop.
Why doesn't this discussion show up on home page? (Score:1)
Re:Why doesn't this discussion show up on home pag (Score:2)
Cable sweetness in older neighborhood (Score:2)
I work from home as much as possible to enjoy a stable, fast Internet connection. At the office, we experience service outages every day (when you're ssh'ed into a remote server, you notice EVERY interruption, dammit) and frequent unexplainable slowdowns (can't blame Napster!).
DSL doesn't share between the CO and the home/office, but it does share SOMEWHERE. Today, for example, I downloaded StarOffice for Windows and Linux from Sun. The first Windows download was corrupted (?) and I had to download it again. Then, stupid me, I realized I downloaded 5.2, so I wen back and downloaded 6.0beta of Windows and Linux. These are ~100 each. So, in less than two hours, while working in the foreground, I downloaded over 400MB from Sun. My sustained transfer rate was over 180Kbps. I would never, ever, attempt such a thing during working hours at the office (on the DSL line). Ever. Downloading Windows patches is painfull enough, believe me.
Ping times are incredible on my cable modem. When I had home DSL I was happy to be able to ping 'nearby' IP addresses in 75ms. Same sites for cable are 10ms usually.
At home I run a linux server and have set up an emergency backup of our production and demo sites incase our dedi-hosted sites go down. I would never have thought of trying that with the office PacBell DSL.
I was a subscriber of Metricom's Ricochet until it died. I used my Ricochet modem at the office, rather than subject myself to the horrors of PacBell DSL.
It could be that my older neighboors don't stress the cable system as a younger demographic would. That could explain why I have NEVER detected a "slow time". And I'm on my connection constantly (ask my poor wife!).
Given the choice, I'll choose cable everytime.
UPDATE - Cable modem slowdown (Score:1)
ATT cable is great, just don't use email (Score:1)
It's 10AM local time on a weekday, where's a pair of concurrent downloads during what is probably "fast time" for home cable and "slow time" for business DSL...
Over ATT cable:
ftp> mget patch-2.4.11.gz
local: patch-2.4.11.gz remote: patch-2.4.11.gz
200 PORT command successful.
150 Opening BINARY mode data connection for patch-2.4.11.gz (941101 bytes).
226 Transfer complete.
941101 bytes received in 2.21 secs (4.2e+02 Kbytes/sec)
ftp>
And at the same time on another machine (at another business) connected to the best local DSL provider on a 512/512 connection (ain't ssh from work great?!):
ftp> mget patch-2.4.11.gz
local: patch-2.4.11.gz remote: patch-2.4.11.gz
200 PORT command successful.
150 Opening BINARY mode data connection for patch-2.4.11.gz (941101 bytes).
226 Transfer complete.
941101 bytes received in 23 secs (40 Kbytes/sec)
ftp>
I can re-run these tonight around 7pm local time and post the evening cable "busy time" results. Not completely scientific, but it should be revealing.
I notice it here (Cambridge, MA) (Score:2)
I don't know much about how to diagnose the problem, but my net connection at work is fine, and I don't notice anything funny when I list connections with netstat or watch total traffic with /proc/net/dev. So I assume it's just overloading of my provider's network.
My situation may be anomalous because I care more about outbound traffic, which is more limited with cable. I've never noticed any problem at home--but then again, I don't usually use my computer at home in the evening, and when I do it's web browsing rather than interactive remote logins.
My service is AT&T Broadband (formerly MediaOne) in 02140.
The reality of the situation is... (Score:1)
Sigifigant speed differences (Score:1)
Rogers@Home (Score:1)
Some of that might have been my modem's fault though as I had to power cycle about once a week. But the cable lines in my area wheren't the best, and there was a filter on the line before I ordered basic cable so that could be it too.
My DSL experience on the other hand is a joke. I called up Sympatico (Bell Canada) and ordered their "high speed" service. Setup kit showed up about a week later via Fedex, and they shipped me *two* install kits. So I unpacked one, set it up, ad installed their software (pppoe). And it didn't work. I call tech support after an hour of playing with it, and I get a french rep that *barely* spoke english and ended up hanging up on me.
I ended up useing my dialup account and calling longdistance to my old isp and downloaded winpoet or something like that and got it working.
My average download speed was roughly 40-60kps (bytes), cable it was alway around 200kps. And my average ping when i fired up TFC or Q3 was NEVER below 100-110, cable 20-35 =P
And between 5pm and 1am DSL was always noticeably slower, ohh and did I forget to mention that the CO was 6 blocks away? and it was a brand new phoneline? Ohh and cable, I was on the router of a city that was 20-25 minutes away =P
So I guess I've had the total opposite experience of most people. Ohhh and Rogers@home was 3mbit down/320kbps up. Sympatico is like 967kbps up/128kbps down.
I doubt it has anything to do with primetime (Score:1)
Slowdowns in Wichita, KS (Score:1)
Of course, lately most of the slowdowns I've seen have been cause by Code Red, etc. I swear, that little activity light never stops blinking.
The problem isn't slowdown for me (Score:1)
The problem is outages. I have excite@home via mediacom, and lately it's been blowing up a lot.
With a DOCSIS cable modem setup, each user has their own downstream frequency range. This range can be used to provide each user (5,000 - 20,000 of which can be on a single MC16 line card, four line cards to a cisco 7246 uBR, I don't know about other manufacturers) with 45 Mbps of downstream bandwidth. Since no one is doing video on demand with them yet, most people are limited to 1.5 or 2.5 Mbps.
Now, the upstream is limited to something like 11 Mbps per upstream channel; When I worked for Cisco they had MC11 line cards with one upstream and one downstream, and MC16 line cards with six upstreams and one downstream. So between 5 and 20 thousand subscribers could be sharing between 11 and 66 Mbps of (theoretical) upstream bandwidth. That could be a bit crowded, but upstream isn't where the emphasis is, anyway.
So what this tells us is that with modern equipment, the problem is not the number of people on your block using the service, though certainly a great deal of legacy cable modem hardware exists. Those markets which just got CM access in the last year or so will probably almost all be DOCSIS installations. The problem is the pipe, and any provider can suffer that, broadband or no. As other posters have noted, that's a problem of oversubscription.