In addition to the performance requirements, ATM networks also introduce new networking concepts which require a revision of current firewall concepts. Performance measurements of firewalls in an ATM network are presented in section 3 . Each cell has a payload of 48 bytes plus a header of 5 bytes.
Cells contain identifiers which allow cells to be associated with a virtual circuit.
This solution is obviously restricted to rather small networks. Instead, ATM will be used as a fast medium to carry Internet protocols. ATM will primarily be used for building fast backbone networks. Only certain applications, such as videoconferencing, require advanced ATM features such as resource reservation. Two widespread concepts are used to transmit IP traffic over ATM networks.