In the IETF working groups and mailing lists related with multicast and in IETF meetings as well people talk about ISPs' requierements for multicast but nobody states clearly which those requierments are. As it is considered that ISPs' opinion on this matter is essential to the development of multicast proposals, could somebody address the questions I have appended bellow or give some pointers to a place where I can find some relevant information regarding this topic ?. Thanks in advance. What do ISPs think about an internet multicast architecture based on running a multicast protocol inside a domain and a different multicast protocol to forward traffic among domains ? What do ISPs think about an internet multicast architecture based on running the same protocol intra and inter domains ? Do ISPs think that any of the current multicast proposals solve they needs ? Where do current proposals fail ? -- Manolo