On 7/1/04 8:14 PM, "Bill Woodcock" <woody@pch.net> wrote:
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.
ISPs don't register it or publish it anywhere, generally, and if you ask salescritters, they're likely to say "At the speed of LIGHT!!!" or some such. But the two methods people would generally use to determine this externally would be first to do a bidirectional traceroute and look closely at the in-addr DNS names associated with the router interfaces on the IX or crossconnect, which, if you trust them, may give you some indication of speed. Next, if you have time, you could run pathchar across the link.
-Bill
Of course, the big issue isn't the size of the links - its utilization. Most private peering links today are OC-12 to OC-192. Most big ISPs do this in a half dozen locations - sometimes more, occasionally less. Of course, you'll use the closest exit between ISPs. Ask your ISP what the utilization of that link is - or what the packet loss is, historically. They are much more likely to tell you that. Its funny, you always see people asking about peering link sizes or locations on RFP's, but they never ask about peering utilization or packet loss. The former is both NDA and meaningless - the latter is terribly important. -- Daniel Golding Network and Telecommunications Strategies Burton Group