Hi Fred, * PLPMTUD is useful. * Designing PMTUD so that it works in the absence of ICMP feedback seems necessary.
BUT * Suitable ICMP feedback hints might significantly improve the performance of a transport protocol. * We can program our transports to react to ICMP as a hint -- i.e., not trust it, but use it to optimize performance. * So ICMP should not be "needed", but it might, and probably would, be quite helpful in some cases. * For instance, not all packetization layers have as easy a time as TCP with packet size changes. The smooth ramp-up suggested in PLPMTUD may require intervention from the application for example. For good performance, these applications may apply PMTUD in unexpected ways -- they might start large, for example. ICMP feedback would really help them. * ICMP is not a significant cause of Internet congestion and need not ever become one (mark it less-than-best-effort). I still think your overloading of ECN capable as "PLPMTUD capable, don't send ICMP" is not necessary, a bad idea, and will not fly. Eddie -------------------------------------------------------------------- IETF IPv6 working group mailing list [EMAIL PROTECTED] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
