nanog mailing list archives
Re: Long hops on international paths
From: William Herrin <bill () herrin us>
Date: Tue, 18 Jan 2022 12:44:26 -0800
On Tue, Jan 18, 2022 at 6:49 AM PAUL R BARFORD <pb () cs wisc edu> wrote:
So, the question is what is the cost/benefit to providers to configure/maintain routes (that include long MPLS tunnels) that tend to concentrate international connectivity at a relatively small number of routers?
Most likely that's not what's happening. None of your traces showed traffic going to Chicago and then doubling back. I can't say with certainty what this means but my educated guess is this: Chicago is a major peering point for the networks in question, so packets headed more or less that direction tend to hop over there instead of somewhere else. Having crossed over, they enter the MPLS system which is opaque to traceroute, so they're not seen again until they exit MPLS. Traffic originating closer to the final destination goes to a scattering of other MPLS entry points instead, so Chicago looks outsized in the data. The actual traffic flow, opaque inside MPLS, goes through the nodes you'd expect, close to the cable landings. So it's not a question of whether the traffic has an international destination, it's a question of whether that backbone is in the path to the destination (international or not). Rephrase your question as: is there a cost/benefit to providers having a small number of very large peering points accepting traffic into their networks in addition to the myriad small ones. Regards, Bill Herrin -- William Herrin bill () herrin us https://bill.herrin.us/
Current thread:
- Re: Long hops on international paths, (continued)
- Re: Long hops on international paths Mark Tinka (Jan 18)
- Re: Long hops on international paths Mike Hammett (Jan 18)
- Re: Long hops on international paths Pengxiong Zhu (Jan 17)
- Re: Long hops on international paths Lady Benjamin Cannon of Glencoe, ASCE (Jan 17)
- Re: Long hops on international paths PAUL R BARFORD (Jan 17)
- Re: Long hops on international paths Christopher Morrow (Jan 17)
- Re: Long hops on international paths PAUL R BARFORD (Jan 17)
- Re: Long hops on international paths David Bass (Jan 18)
- Re: Long hops on international paths PAUL R BARFORD (Jan 18)
- Re: Long hops on international paths Nick Hilliard (Jan 18)
- Re: Long hops on international paths William Herrin (Jan 18)
- RE: Long hops on international paths Adam Thompson (Jan 25)
- Re: Long hops on international paths PAUL R BARFORD (Jan 25)
- Re: Long hops on international paths Dave Cohen (Jan 17)