Re: Bandwidth issues in the Sprint network
Has this circuit ever run clean(normal)? -M On Mon, Apr 7, 2008 at 1:06 PM, Brian Raaen [EMAIL PROTECTED] wrote: I am currently having problems get upload bandwidth on a Sprint circuit. I am using a full OC3 circuit. I am doing fine on downloading data, but uploading data I can only get about 5Mbps with ftp or a speedtest. I have tested against multiple networks and this has stayed the same. Monitoring Cacti graphs and the router I do get about 30Mbps total traffic outbound, but individual (flows/ip?) test always seem limited. I would like to know if anyone else sees anything similar, or where I can get help. The assistance I have gotten from Sprint up to this point is that they find no problems. Due to the consistency of 5Mbps I am suspecting rate limiting, but wanted to know if I was overlooking something else. -- Brian Raaen Network Engineer [EMAIL PROTECTED]
Re: Does TCP Need an Overhaul? (internetevolution, via slashdot)
On Mon, Apr 7, 2008 at 8:43 AM, Iljitsch van Beijnum [EMAIL PROTECTED] wrote: On 7 apr 2008, at 16:20, Kevin Day wrote: As a quick example on two FreeBSD 7.0 boxes attached directly over GigE, with New Reno, fast retransmit/recovery, and 256K window sizes, with an intermediary router simulating packet loss. A single HTTP TCP session going from a server to client. Ok, assuming a 1460 MSS that leaves the RTT as the unknown. SACK enabled, 0% packet loss: 780Mbps SACK disabled, 0% packet loss: 780Mbps Is that all? Try with jumboframes. SACK enabled, 0.005% packet loss: 734Mbps SACK disabled, 0.005% packet loss: 144Mbps (19.6% the speed of having SACK enabled) 144 Mbps and 0.5 packet loss probability would result in a ~ 110 ms RTT so obviously something isn't right with that case. 734 would be an RTT of around 2 ms, which sounds fairly reasonable. I'd be interested to see what's really going on here, I suspect that the packet loss isn't sufficiently random so multiple segments are lost from a single window. Or maybe disabling SACK also disables fast retransmit? I'll be happy to look at a tcpdump for the 144 Mbps case. It would be very nice if more network-friendly protocols were in use, but with download optimizers for Windows that cranks the TCP window sizes way up, the general move to solving latency by opening more sockets, and P2P doing whatever it can to evade ISP detection - it's probably a bit late. Don't forget that the user is only partially in control, the data also has to come from somewhere. Service operators have little incentive to break the network. And users would probably actually like it if their p2p was less aggressive, that way you can keep it running when you do other stuff without jumping through traffic limiting hoops. This might have been mentioned earlier in the thread, but has anyone read the paper by Bob Briscoe titled Flow Rate Fairness:Dismantling a Religion? http://www.cs.ucl.ac.uk/staff/bbriscoe/projects/2020comms/refb/draft-briscoe-tsvarea-fair-02.pdf The paper essentially describes the fault in TCP congestion avoidance and how P2P applications leverage that flaw to consume as much bandwidth as possible. He also proposes that we redefine the mechanism we use to determine fair resource consumption. His example is individual flow rate fairness (traditional TCP congestion avoidance) vs cost fairness (a combination of congestion cost and flow rate associated with a specific entity). He also compares his cost fairness methodology to existing proposed TCP variants, which Hank previously mentioned. i.e. XCP, WFQ, ... Any thoughts regarding this? -Mike Gonnason
Re: Bandwidth issues in the Sprint network
Currently there is not a proxy server in the network, although when using some of the test on dslreports.com there is a message about compression being used for the upload and to remove proxy settings. I have also been testing using FTP on a *nix server as well. Both the server and PC are connect to a Cisco 2960 switch in the headend that is connected to the 7200 router. I can transfer ftp at about 80Mbps between the PC and the server, so they are not IO bound. The Site I am testing with is a ftp server located in a colo facility that we use and has sufficient bandwidth. This circuit is clean in the sense of not having CRC, framing or other errors but this is a new circuit and we have never gotten more than 5Mbps out of a single session (flow/ip) across the wan. I would have to double check the mtu, but it is currently the default. -- Brian Raaen Network Engineer [EMAIL PROTECTED] On Monday 07 April 2008, Brian Raaen wrote: I am currently having problems get upload bandwidth on a Sprint circuit. I am using a full OC3 circuit. I am doing fine on downloading data, but uploading data I can only get about 5Mbps with ftp or a speedtest. I have tested against multiple networks and this has stayed the same. Monitoring Cacti graphs and the router I do get about 30Mbps total traffic outbound, but individual (flows/ip?) test always seem limited. I would like to know if anyone else sees anything similar, or where I can get help. The assistance I have gotten from Sprint up to this point is that they find no problems. Due to the consistency of 5Mbps I am suspecting rate limiting, but wanted to know if I was overlooking something else. -- Brian Raaen Network Engineer [EMAIL PROTECTED] signature.asc Description: This is a digitally signed message part.
RE: Bandwidth issues in the Sprint network
Try using the Java test on DSLReports rather than the Flash based test. I've found it to be much more accurate. I also receive the message about compression being used when I test with the flash test. I think it may be a bug. Matthew Evans, MCSA Alpha Theory | “the right decision, every time.” 2201 Coronation Blvd., Suite 140 Charlotte, NC 28227 (704) 307-2914 x205 www.alphatheory.com ALPHA THEORY QUICK DEMO (click here) -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Raaen Sent: Tuesday, April 08, 2008 9:49 AM To: nanog@merit.edu Subject: Re: Bandwidth issues in the Sprint network Currently there is not a proxy server in the network, although when using some of the test on dslreports.com there is a message about compression being used for the upload and to remove proxy settings. I have also been testing using FTP on a *nix server as well. Both the server and PC are connect to a Cisco 2960 switch in the headend that is connected to the 7200 router. I can transfer ftp at about 80Mbps between the PC and the server, so they are not IO bound. The Site I am testing with is a ftp server located in a colo facility that we use and has sufficient bandwidth. This circuit is clean in the sense of not having CRC, framing or other errors but this is a new circuit and we have never gotten more than 5Mbps out of a single session (flow/ip) across the wan. I would have to double check the mtu, but it is currently the default. -- Brian Raaen Network Engineer [EMAIL PROTECTED] On Monday 07 April 2008, Brian Raaen wrote: I am currently having problems get upload bandwidth on a Sprint circuit. I am using a full OC3 circuit. I am doing fine on downloading data, but uploading data I can only get about 5Mbps with ftp or a speedtest. I have tested against multiple networks and this has stayed the same. Monitoring Cacti graphs and the router I do get about 30Mbps total traffic outbound, but individual (flows/ip?) test always seem limited. I would like to know if anyone else sees anything similar, or where I can get help. The assistance I have gotten from Sprint up to this point is that they find no problems. Due to the consistency of 5Mbps I am suspecting rate limiting, but wanted to know if I was overlooking something else. -- Brian Raaen Network Engineer [EMAIL PROTECTED]
Re: Bandwidth issues in the Sprint network
Could be your TCP window size? A 17520 byte TCP window (Windows 2000) will cause a single flow to top out at 5Mbps at about 50ms. What is the latency on the link? Try some figures here and see what limit you might be hitting: http://www.wand.net.nz/~perry/max_download.php?bits_per_second=15500ack_size=40no_delayed_acks=2mss=1460rtt=35wsize=17520ploss=0 Sam Brian Raaen wrote: I am currently having problems get upload bandwidth on a Sprint circuit. I am using a full OC3 circuit. I am doing fine on downloading data, but uploading data I can only get about 5Mbps with ftp or a speedtest. I have tested against multiple networks and this has stayed the same. Monitoring Cacti graphs and the router I do get about 30Mbps total traffic outbound, but individual (flows/ip?) test always seem limited. I would like to know if anyone else sees anything similar, or where I can get help. The assistance I have gotten from Sprint up to this point is that they find no problems. Due to the consistency of 5Mbps I am suspecting rate limiting, but wanted to know if I was overlooking something else.
Re: Bandwidth issues in the Sprint network
I have been using the Java based versions of the speed test. At this point I have had some Sprint people get in contact with me so I will see what they find. Thank you for all your help to everyone. -- Brian Raaen Network Engineer [EMAIL PROTECTED] On Monday 07 April 2008, you wrote: I am currently having problems get upload bandwidth on a Sprint circuit. I am using a full OC3 circuit. I am doing fine on downloading data, but uploading data I can only get about 5Mbps with ftp or a speedtest. I have tested against multiple networks and this has stayed the same. Monitoring Cacti graphs and the router I do get about 30Mbps total traffic outbound, but individual (flows/ip?) test always seem limited. I would like to know if anyone else sees anything similar, or where I can get help. The assistance I have gotten from Sprint up to this point is that they find no problems. Due to the consistency of 5Mbps I am suspecting rate limiting, but wanted to know if I was overlooking something else. -- Brian Raaen Network Engineer [EMAIL PROTECTED] signature.asc Description: This is a digitally signed message part.
Speedtest site accuracy [was: Bandwidth issues in the Sprint network]
--- [EMAIL PROTECTED] wrote: Try using the Java test on DSLReports rather than the Flash based test. I've found it to be much more accurate. I also receive the message about compression being used when I test with the flash test. I think it may be a bug. --- This brings up a PITA point for me. Recently, I have seen a rash of Speedsite test server at location says blah, blah, blah tickets finally reach me and I am telling everyone they're not an accurate way to measure network performance. I notice that at least some are just sending text in Latin. To other medium-sized eyeball network providers (I'm defining medium size as 50-150K DSL/Cable connections and 50-1500 leased line customers): are you seeing this and what do you tell your customers? scott
RE: Speedtest site accuracy [was: Bandwidth issues in the Sprint network]
We have an test server inside our network that we have customers test again. We tell customers that we can only control our network -- beyond our upstream routers it's best-effort only. That said, if there is a real performance issue upstream we do our best to assist or point the customer in the right direction. Frank -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Scott Weeks Sent: Tuesday, April 08, 2008 1:16 PM To: nanog@merit.edu Subject: Speedtest site accuracy [was: Bandwidth issues in the Sprint network] --- [EMAIL PROTECTED] wrote: Try using the Java test on DSLReports rather than the Flash based test. I've found it to be much more accurate. I also receive the message about compression being used when I test with the flash test. I think it may be a bug. --- This brings up a PITA point for me. Recently, I have seen a rash of Speedsite test server at location says blah, blah, blah tickets finally reach me and I am telling everyone they're not an accurate way to measure network performance. I notice that at least some are just sending text in Latin. To other medium-sized eyeball network providers (I'm defining medium size as 50-150K DSL/Cable connections and 50-1500 leased line customers): are you seeing this and what do you tell your customers? scott
Re: Speedtest site accuracy [was: Bandwidth issues in the Sprint network]
On Tue, Apr 8, 2008 at 11:15 AM, Scott Weeks [EMAIL PROTECTED] wrote: This brings up a PITA point for me. Recently, I have seen a rash of Speedsite test server at location says blah, blah, blah tickets finally reach me and I am telling everyone they're not an accurate way to measure network performance. I notice that at least some are just sending text in Latin. To other medium-sized eyeball network providers (I'm defining medium size as 50-150K DSL/Cable connections and 50-1500 leased line customers): are you seeing this and what do you tell your customers? We tell our customers to make sure to use the test site on our network, which will be quite a bit more accurate than some random location on the internet they might pick. There's no reason it can't be reasonably accurate, if you care to address it. We normally get within a few percent of a given line rate ranging over normal DSL speeds to T1s to DS3s to Fast Ethernet. It's a very easy and user-understandable way to say Your T1 is installed, there's no errors that we see, you're getting about 1.4mbit on the speed test, have a nice day, or, alternately, You're getting 95mbit/sec down and only 45mbit/sec up, you probably have a duplex mixmatch on your newly installed colo server. --Doug
Re: Speedtest site accuracy [was: Bandwidth issues in the Sprint network]
On Tue, 8 Apr 2008, Scott Weeks wrote: To other medium-sized eyeball network providers (I'm defining medium size as 50-150K DSL/Cable connections and 50-1500 leased line customers): are you seeing this and what do you tell your customers? We're having this big push here in Sweden with something that basically translates into broadband checkup. It's also web based, and it ended up in the national papers last week, where the newspapers misinterpreted 9.53 megabit/s of TCP thruput on a 10 meg ethernet connection as barely acceptable or something of that nature. We're seeing difference in results on the same computer depending on what browser is being used, and other strange results. Yes, it's a basic test and it should be treated that way, unfortunately quite a lot of users expect to get the same number they have purchased, so when they have purchased 8 megabit ADSL, they expect this test to say 8 megabit/s. Industry standard here is that 8/1 is ATM speed, so best results one can expect is approx 6.7 megabit/s of TCP thruput. So yes, this is seen and it's a problem I guess we as an industry have to learn how to handle. Swedish ISPs are adopting fineprint in their ads on expected speed to be seen in this tool, as it seems the users are very keen on using it. What worries me is that people will get dissatisfied with their connection even though there is nothing wrong with it and that they won't get better service elsewhere if they switch ISPs. It's good that there is a test, but since we're a market where 100/100 ethernet connections are fairly prevalent, this test doesn't work properly (75 megabit/s result on a 100/100 was listed in the paper as not acceptable which we all understand is unfair). -- Mikael Abrahamssonemail: [EMAIL PROTECTED]
Re: Superfast internet may replace world wide web
[EMAIL PROTECTED] wrote:
On Mon, 07 Apr 2008 17:36:09 +0200, Thomas Kernen said:
And those of us that live next to the LHC wonder if we will be sucked
into a {vortex|wormhole}.
You mean like this?
http://ars.userfriendly.org/cartoons/?id=20080406mode=classic
Sounds about right... so maybe one of the benefits of spending most of
my time on the road. I might not actually be there when they power it up.
T
Re: Does TCP Need an Overhaul? (internetevolution, via slashdot)
Mike Gonnason wrote: This might have been mentioned earlier in the thread, but has anyone read the paper by Bob Briscoe titled Flow Rate Fairness:Dismantling a Religion? http://www.cs.ucl.ac.uk/staff/bbriscoe/projects/2020comms/refb/draft-briscoe-tsvarea-fair-02.pdf The paper essentially describes the fault in TCP congestion avoidance and how P2P applications leverage that flaw to consume as much bandwidth as possible. He also proposes that we redefine the mechanism we use to determine fair resource consumption. Any thoughts regarding this? The problem is that fairness was probably never a design goal of TCP, even with Van Jacobson's congestion avoidance patch. Bob Briscoe is a member of the IETF Transport Working Group (TSVWG). This subject got some publicity and politics involved, but please see some real discussion on the TSVWG list, with my favorite answer highlighted: http://thread.gmane.org/gmane.ietf.tsvwg/5184/focus=5199 I recommend some neighboring threads as well: http://thread.gmane.org/gmane.ietf.tsvwg/5197/focus=5214 http://thread.gmane.org/gmane.ietf.tsvwg/5205 -- Marcin Cieslak // [EMAIL PROTECTED] signature.asc Description: OpenPGP digital signature
Dubai impound ships suspected in cable damage
Wow, civilian satellite images are getting very sharp. http://www.hindu.com/2008/04/07/stories/2008040759181200.htm Using satellite images of ship movements in the area, Reliance Globalcom identified two ships in the area at the time which may have damaged the cable. Reliance also confirmed the cable was damaged because of jerks and force of the ship.
Re: Does TCP Need an Overhaul? (internetevolution, via slashdot)
On Wed, Apr 09, 2008 at 01:10:53AM +0200, Marcin Cieslak wrote: The problem is that fairness was probably never a design goal of TCP, even with Van Jacobson's congestion avoidance patch. Bob Briscoe is a member of the IETF Transport Working Group (TSVWG). This subject got some publicity and politics involved, but please see some real discussion on the TSVWG list, with my favorite answer highlighted: This issue also got some publicity and politics on the IRTF end2end list. For example, start at http://www.postel.org/pipermail/end2end-interest/2007-August/006925.html . --gregbo
Re: Dubai impound ships suspected in cable damage
There is no reason to assume these are civilian satellites. Any one of a number of affected or interested countries could have provided the imagery (or ship information) to Reliance. Its not saying *who* analyzed the images. ;) Then again, how are ship's captains supposed to know *where* they are allowed to drop anchor? Is there a Call before you drop anchor service similar to call before you dig? Deepak Sean Donelan wrote: Wow, civilian satellite images are getting very sharp. http://www.hindu.com/2008/04/07/stories/2008040759181200.htm Using satellite images of ship movements in the area, Reliance Globalcom identified two ships in the area at the time which may have damaged the cable. Reliance also confirmed the cable was damaged because of jerks and force of the ship.
Re: Dubai impound ships suspected in cable damage
On Apr 8, 2008, at 7:57 PM, Deepak Jain wrote: There is no reason to assume these are civilian satellites. Any one of a number of affected or interested countries could have provided the imagery (or ship information) to Reliance. Its not saying *who* analyzed the images. ;) Then again, how are ship's captains supposed to know *where* they are allowed to drop anchor? Is there a Call before you drop anchor service similar to call before you dig? That's what maritime pilots are for (every commercial harbor has them) and my understanding is that they are generally required by law and that there can be criminal penalties for not following their advice. Regards Marshall Deepak Sean Donelan wrote: Wow, civilian satellite images are getting very sharp. http://www.hindu.com/2008/04/07/stories/2008040759181200.htm Using satellite images of ship movements in the area, Reliance Globalcom identified two ships in the area at the time which may have damaged the cable. Reliance also confirmed the cable was damaged because of jerks and force of the ship.
Re: Dubai impound ships suspected in cable damage
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 - -- Deepak Jain [EMAIL PROTECTED] wrote: There is no reason to assume these are civilian satellites. I'm glad you said it -- I was just about to utter the same. ;-) - - ferg -BEGIN PGP SIGNATURE- Version: PGP Desktop 9.6.3 (Build 3017) wj8DBQFH/Aq5q1pz9mNUZTMRAimlAJwJ6iNNiXMF7w+yR+GrNE2jW1B2NgCghbxv rwfmQtPdVP+1mQ34WyQ9B4Y= =LL9c -END PGP SIGNATURE- -- Fergie, a.k.a. Paul Ferguson Engineering Architecture for the Internet fergdawg(at)netzero.net ferg's tech blog: http://fergdawg.blogspot.com/
Re: Dubai impound ships suspected in cable damage
On Tue, Apr 8, 2008 at 5:57 PM, Deepak Jain [EMAIL PROTECTED] wrote: There is no reason to assume these are civilian satellites. Any one of a number of affected or interested countries could have provided the imagery (or ship information) to Reliance. Its not saying *who* analyzed the images. ;) You can purchase these things from sattelite image services these days as well as get them from intelligence services. Then again, how are ship's captains supposed to know *where* they are allowed to drop anchor? Is there a Call before you drop anchor service similar to call before you dig? The Captain has a responsibility to know where proper anchorages are. That, and they are required to know where oil pipelines, utilities, and other types of cables are run including communications cables. There is a lot of stuff under the water. Cable operators also provide specific locating data so that Captains do have information available to avoid these issues. If it was the result of the specific ships that they've surveilled, it's likely that they were off anchorage and slipping their anchor. The anchor catches the cable and then the cable snaps under it's own weight from the pulling. -M
RE: Dubai impound ships suspected in cable damage
If the military can tell a persons sex by shadows in a photo, how tough can it be to ID a ship several football fields in length when they are painted to make them easy to ID. Robert D. Scott [EMAIL PROTECTED] Senior Network Engineer 352-273-0113 Phone CNS - Network Services 352-392-2061 CNS Receptionist University of Florida 352-392-9440 FAX Florida Lambda Rail 352-294-3571 FLR NOC Gainesville, FL 32611 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Ferguson Sent: Tuesday, April 08, 2008 8:16 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; nanog@merit.edu Subject: Re: Dubai impound ships suspected in cable damage -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 - -- Deepak Jain [EMAIL PROTECTED] wrote: There is no reason to assume these are civilian satellites. I'm glad you said it -- I was just about to utter the same. ;-) - - ferg -BEGIN PGP SIGNATURE- Version: PGP Desktop 9.6.3 (Build 3017) wj8DBQFH/Aq5q1pz9mNUZTMRAimlAJwJ6iNNiXMF7w+yR+GrNE2jW1B2NgCghbxv rwfmQtPdVP+1mQ34WyQ9B4Y= =LL9c -END PGP SIGNATURE- -- Fergie, a.k.a. Paul Ferguson Engineering Architecture for the Internet fergdawg(at)netzero.net ferg's tech blog: http://fergdawg.blogspot.com/
Re: Dubai impound ships suspected in cable damage
On Tue, 8 Apr 2008 19:31:47 -0400 (EDT) Sean Donelan [EMAIL PROTECTED] wrote: Wow, civilian satellite images are getting very sharp. http://www.hindu.com/2008/04/07/stories/2008040759181200.htm Using satellite images of ship movements in the area, Reliance Globalcom identified two ships in the area at the time which may have damaged the cable. Reliance also confirmed the cable was damaged because of jerks and force of the ship. Thanks. I wish, though, the article had said *which* cable cuts those ships were responsible for -- remember that Egyptian authorities had said that their videos showed no ships off Alexandria. There's a bit more at http://web20.telecomtv.com/pages/?newsid=42942id=e9381817-0593-417a-8639-c4c53e2a2a10view=news --Steve Bellovin, http://www.cs.columbia.edu/~smb
Re: Dubai impound ships suspected in cable damage
On Tue, 8 Apr 2008, Martin Hannigan wrote: You can purchase these things from sattelite image services these days as well as get them from intelligence services. Awesome, so could anyone buy a copy of the same images? Which satellite do you think happened to be taking images of the area with these ships near the time the cables were broken? Which company is selling that set of images?
Re: Dubai impound ships suspected in cable damage
At 11:49 PM 08-04-08 -0400, Sean Donelan wrote: On Tue, 8 Apr 2008, Martin Hannigan wrote: You can purchase these things from sattelite image services these days as well as get them from intelligence services. Awesome, so could anyone buy a copy of the same images? Which satellite do you think happened to be taking images of the area with these ships near the time the cables were broken? Which company is selling that set of images? http://www.eyeofdubai.com/v1/news/newsdetail-19123.htm -Hank
Re: Dubai impound ships suspected in cable damage
Hank Nussbacher wrote: At 11:49 PM 08-04-08 -0400, Sean Donelan wrote: On Tue, 8 Apr 2008, Martin Hannigan wrote: You can purchase these things from sattelite image services these days as well as get them from intelligence services. Awesome, so could anyone buy a copy of the same images? Which satellite do you think happened to be taking images of the area with these ships near the time the cables were broken? Which company is selling that set of images? http://www.eyeofdubai.com/v1/news/newsdetail-19123.htm Those are geostationary. hybrid in this case implies wide medium and narrow beam applications, like voice tv and internet... http://space.skyrocket.de/index_frame.htm?http://www.skyrocket.de/space/doc_sdat/yahsat-1.htm -Hank
