The compound VC switch. A non-VC merge ATM multicast switch

VC merge has been presented as the most likely implementation to offer multicast forwarding in MPLS environments when ATM is used as data link layer. But it presents some characteristics that may not be desirable, like extra buffering and delay, and modification of traffic characteristics. Other types of mechanisms are presented in the literature to solve these problems. Compound VC (CVC) is one of these mechanisms. This paper presents a general comparison of VC merge and CVC. It finally discusses the implementation issues of a CVC switch. Though its implementation is more complex, it is shown that CVC forwarding could be carried out by using state-of-the-art ATM hardware.