Thank you for the beginnings of a more focused discussion on these hard issues! I particularly thank Bill Woodcock for a much more thorough treatise with diagrams which elucidates the major issues. I am convinced that his argument is substantially correct. The limitation on interconnection is both a technical and socially undesirable end. Sean Doran advanced some thoughtful solutions for these problems (although it took more than one reading for me to understand). So, given that the current policies of large providers promote network congestion, poor topology engineering, and discourage competition, what policies should we create to fix this problem? Wouldn't XP policies more in line with those of CIX be to everyone's advantage? As Sanjay Dani correctly states, "if these issues are not resolved within the ISP community it won't be too long before courts force the issues." What technology do we need to implement these better policies? Is expanding BGP/IDRP for Sean's AS metric suggestion already being done? Another issue that was raised was the cost of exchanging bilateral routes with more ISPs at an XP, and inability to trust the small ISPs to properly configure. In reality, we have seen that even large ISPs are badly configured from time to time, and therefore the "smallness" is a bogus point, although the trust issue remains. Wouldn't that be solved by having each ISP peer with the XP instead of every other ISP, reducing from N**2 to N? Cannot the ISPs trust the XP to be properly configured? Isn't this what is already done with the RA project? WSimpson@UMich.edu Key fingerprint = 17 40 5E 67 15 6F 31 26 DD 0D B9 9B 6A 15 2C 32 BSimpson@MorningStar.com Key fingerprint = 2E 07 23 03 C5 62 70 D3 59 B1 4F 5E 1D C2 C1 A2