The purpose of this paper is to have a closer look at the 'core' techn
ology providing interworking between connectionless TCP/IP internetwor
ks and switched ATM networks. The scope of the paper is LP multicast,
while the main focus is on the network side of multicast, more precise
ly, on layers three and two of Internet architecture dealing with IP m
ulticast routing. The paper analyses both practically available soluti
ons and those being currently under discussion in IETF as Internet dra
fts. As a background of this comparison, the possible convergence of L
P and ATM multicast service models is discussed. Major conclusions, ba
sed on simulation studies and scalability analysis are: (i) the high m
apping overhead requires a separate address resolution service for uni
cast and multicast addresses: and (ii) efficient convergence has to ma
ke obsolete classical IP over ATM (M. Laubach, Classical IP and ARP ov
er ATM, Network Working Group. Request for Comments: 1577, Category: S
tandards Track, January, 1994 [1]) in order to permit 'cut-through' wi
thin the ATM domain. (C) 1998 Elsevier Science B.V.