ATM protocol on LAN

ATM is connection oriented and needs to establish VPI/VCI tables in switches before transmission can occur. This requires the connectionless messages to be segmented, reassembled and encapsulated. It is said that the 48 bit address attached to the connectionless messages which are expressed with VPI/VCI and bit information correlated with this, should relevantly be called MAC logical address. ATM connections between ELAN on various logical links apply some forms of bandwidth reservation, which is dynamic or half permanent according to peak value width of data transmission and the bursty frequency-it is said that the reservation of bandwidth can be modified if it is necessary. Connectionless service was provided directly over B-ISDN and the cells were transmitted according to routing information. So a part of the processing functions are distributed to switches. The switch integrates itself with a router, virtual LAN and structure of ATM switch and has a key function, a capacity to multicast MAC frames. The server lies on the known virtual channel, it is an appropriate recentralization of distributed functions so as to simplify the functions of unnecessary repetition inside the network. The “segmenting” can increase bandwidth much more and bring about SVC (switched virtual circuits). If the cells from various resources transmit to one certain segment, the header will have the same VPI/VCI