> Anyway, with IPv6 the address format is fundamentally incompatible with > that of IPv4 so there is no choice but running them concurrently during > the transition period. A new multihoming-capable transport protocol > doesn't have to be incompatible with existing TCP so this situation is > avoidable here. It does not seem reasonable to compare the IPv6/IPv4 deployment and SCTP/TCP deployment. SCTP and TCP are basically the end-to-end protocols so that hosts/terminals have only to have them, whereas IPv4 and IPv6 are subject to network support or change. IMHO, we don't need to worry about inter-operablity or compatibilty between SCTP and TCP. I mean SCTP will be used by the new emerging applications and services including mobile internet stuffs, for example, between mobile clients and contents servers of the M-ISP. Seok J. Koh