Very true.. Work with the network operators on each side of the link to determine the speed/load. For the most part if they really want your business, they will be able to provide something. The main reason link speed maybe important to me would serialization delay on the circuit. OC-768 should be much lower latency than a T1...unless your are at the end of the queue :-) Latency is probably be your primary concern for large TCP transfers anyway. -C -----Original Message----- From: Tony Li [mailto:tony.li@tony.li] Sent: Thursday, July 01, 2004 7:02 PM To: Cody Lerum Cc: erik@myevilempire.net; nanog@merit.edu; network.support@oati.net Subject: Re: Peering point speed publicly available? Is it really important to know the link speeds? What good does it do without knowing about the loading on those links? I would MUCH rather have an empty T1 than have to contend with a very oversubscribed OC-768. Tony On Jul 1, 2004, at 5:25 PM, Cody Lerum wrote:
DNS can sometimes give you a hint [my nets snipped] 4 t3-1-2-0.ar2.SEA1.gblx.net (64.211.206.113) 20.436 ms 18.309 ms 17.605 ms <------------DS3 5 so1-0-0-2488M.ar4.SEA1.gblx.net (67.17.71.210) 17.607 ms 16.982 ms 16.971 ms <-----OC-48 6 p3-3.IR1.Seattle-WA.us.xo.net (206.111.7.5) 17.864 ms 19.491 ms 17.181 ms 7 p5-1-0-3.RAR1.Seattle-WA.us.xo.net (65.106.0.197) 17.723 ms 17.632 ms 19.045 ms 8 65.106.0.50 (65.106.0.50) 38.133 ms 39.197 ms 49.961 ms MPLS Label=101549 CoS=0 TTL=1 S=1 9 p0-0-0d0.RAR1.SanJose-CA.us.xo.net (65.106.1.61) 37.669 ms 38.572 ms 36.517 ms 10 p7-0.DCR1.DC-SanJose-CA.us.xo.net (65.106.2.146) 37.830 ms 36.524 ms 37.743 ms 11 ge1-1.CDR2.DC-SanJose-CA.us.xo.net (209.220.168.10) 38.428 ms 38.050 ms 37.179 ms <-----Gig Ethernet 12 205.158.6.100.ptr.us.xo.net (205.158.6.100) 40.179 ms 39.784 ms 39.444 ms 13 x218.cd9e6c.sj.concentric.net (205.158.108.218) 39.188 ms 39.723 ms 39.895 ms However MPLS hidden hops may hide internal paths, and any connection may be limited to slower than its line rate, and dns entries may be old.... It's not publicly available at one source that I'm aware of, and if there is they don't have my info. -C From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Erik Amundson Sent: Thursday, July 01, 2004 6:10 PM To: nanog@merit.edu Cc: network.support@oati.net Subject: Peering point speed publicly available?
NANOG,
I have a question regarding information on my ISP's peering relationships. Are the speeds of some or all peering relationships public knowledge, and if so, where can I find this? By speed, I mean bandwidth (DS3, OC3, 100Mbps, 1Gbps, etc.). I am trying to transfer large stuff from my AS, through my ISP, through another ISP, to another AS, and I'm wondering how fast the peering point is between the ISPs. I'm working with my provider to get this information as we speak, but I'm wondering if it's available publicly anywhere. If it were, this could be one way to evaluate providers in the future, I guess...
Erik Amundson A+, N+, CCNA, CCNP IT and Network Manager Open Access Technology Int'l, Inc. Phone (763) 201-2005 Fax (763) 553-2813 mailto:erik.amundson@oati.net
On Thu, Jul 01, 2004 at 07:05:51PM -0600, Cody Lerum wrote:
Work with the network operators on each side of the link to determine the speed/load. For the most part if they really want your business, they will be able to provide something.
Actually, many larger peering relationships come with contracts which explicitly forbid them from telling you any details about link capacity or utilization, or in some cases even acknowledging that peering exists. They might tell you anyways though. :) For the most part, it is hope for descriptive DNS or bust. For the most part, DNS is not descriptive (especially on peering links). :)
The main reason link speed maybe important to me would serialization delay on the circuit. OC-768 should be much lower latency than a T1...unless your are at the end of the queue :-)
Once you get past 10Mbps, serialization delay is measured in fractions of a millisecond. This has absolutely no impact on TCP performance, compared to speed of light delays (like from oh say a 50ft patch cable).
Latency is probably be your primary concern for large TCP transfers anyway.
I think that you are very confused about how TCP works.
4 t3-1-2-0.ar2.SEA1.gblx.net (64.211.206.113) 20.436 ms 18.309 ms 17.605 ms <------------DS3 5 so1-0-0-2488M.ar4.SEA1.gblx.net (67.17.71.210) 17.607 ms 16.982 ms 16.971 ms <-----OC-48 6 p3-3.IR1.Seattle-WA.us.xo.net (206.111.7.5) 17.864 ms 19.491 ms 17.181 ms
Name: p3-3.IR1.Seattle-WA.us.xo.net Address: 206.111.7.5 Name: 206.111.7.6.ptr.us.xo.net Address: 206.111.7.6 Sometimes you can find descriptive DNS on the other side of the PTR, and sometimes you find missing data. In this case, there is no speed description at all. The p3-3 interface indicates that this is a PoS interface, probably Cisco, and the IR designation on XO indicates a peering router. Educated hunch based on what the traffic levels between 3549 and 2828 in Seattle probably are... OC3? -- Richard A Steenbergen <ras@e-gerbil.net> http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)
Of course individual links are likely to have little difference .. it'll come down to a combination of the smallest link between source and destination and the end to end latency. Steve On Thu, 1 Jul 2004, Cody Lerum wrote:
Work with the network operators on each side of the link to determine the speed/load. For the most part if they really want your business, they will be able to provide something.
The main reason link speed maybe important to me would serialization delay on the circuit. OC-768 should be much lower latency than a T1...unless your are at the end of the queue :-)
Latency is probably be your primary concern for large TCP transfers anyway.
-C
-----Original Message----- From: Tony Li [mailto:tony.li@tony.li] Sent: Thursday, July 01, 2004 7:02 PM To: Cody Lerum Cc: erik@myevilempire.net; nanog@merit.edu; network.support@oati.net Subject: Re: Peering point speed publicly available?
Is it really important to know the link speeds? What good does it do without knowing about the loading on those links?
I would MUCH rather have an empty T1 than have to contend with a very oversubscribed OC-768.
Tony
On Jul 1, 2004, at 5:25 PM, Cody Lerum wrote:
DNS can sometimes give you a hint [my nets snipped] 4 t3-1-2-0.ar2.SEA1.gblx.net (64.211.206.113) 20.436 ms 18.309 ms 17.605 ms <------------DS3 5 so1-0-0-2488M.ar4.SEA1.gblx.net (67.17.71.210) 17.607 ms 16.982 ms 16.971 ms <-----OC-48 6 p3-3.IR1.Seattle-WA.us.xo.net (206.111.7.5) 17.864 ms 19.491 ms 17.181 ms 7 p5-1-0-3.RAR1.Seattle-WA.us.xo.net (65.106.0.197) 17.723 ms 17.632 ms 19.045 ms 8 65.106.0.50 (65.106.0.50) 38.133 ms 39.197 ms 49.961 ms MPLS Label=101549 CoS=0 TTL=1 S=1 9 p0-0-0d0.RAR1.SanJose-CA.us.xo.net (65.106.1.61) 37.669 ms 38.572 ms 36.517 ms 10 p7-0.DCR1.DC-SanJose-CA.us.xo.net (65.106.2.146) 37.830 ms 36.524 ms 37.743 ms 11 ge1-1.CDR2.DC-SanJose-CA.us.xo.net (209.220.168.10) 38.428 ms 38.050 ms 37.179 ms <-----Gig Ethernet 12 205.158.6.100.ptr.us.xo.net (205.158.6.100) 40.179 ms 39.784 ms 39.444 ms 13 x218.cd9e6c.sj.concentric.net (205.158.108.218) 39.188 ms 39.723 ms 39.895 ms However MPLS hidden hops may hide internal paths, and any connection may be limited to slower than its line rate, and dns entries may be old.... It's not publicly available at one source that I'm aware of, and if there is they don't have my info. -C From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Erik Amundson Sent: Thursday, July 01, 2004 6:10 PM To: nanog@merit.edu Cc: network.support@oati.net Subject: Peering point speed publicly available?
NANOG,
I have a question regarding information on my ISP's peering relationships. Are the speeds of some or all peering relationships public knowledge, and if so, where can I find this? By speed, I mean bandwidth (DS3, OC3, 100Mbps, 1Gbps, etc.). I am trying to transfer large stuff from my AS, through my ISP, through another ISP, to another AS, and I'm wondering how fast the peering point is between the ISPs. I'm working with my provider to get this information as we speak, but I'm wondering if it's available publicly anywhere. If it were, this could be one way to evaluate providers in the future, I guess...
Erik Amundson A+, N+, CCNA, CCNP IT and Network Manager Open Access Technology Int'l, Inc. Phone (763) 201-2005 Fax (763) 553-2813 mailto:erik.amundson@oati.net
participants (3)
-
Cody Lerum -
Richard A Steenbergen -
Stephen J. Wilcox