Editing Cell relay (section)

===How Cell Relay Works===
Cell relay systems break variable-length user packets into groups of fixed-length cells, that add addressing and verification information. [[frame (telecommunications)|Frame]] length is fixed in [[networking hardware]], based on time delay and user packet-length considerations. One user data message may be segmented over many cells.

Cell relay systems may also carry bitstream-based data such as [[Plesiochronous Digital Hierarchy|PDH]] traffic, by breaking it into streams of cells, with a lightweight synchronization and clock recovery shim. Thus cell relay systems may potentially carry any combination of stream-based and packet-based data. This is a form of [[statistical time division multiplexing]].

Cell relay is an implementation of [[Fast packet switching|fast packet-switching]] technology that is used in connection-oriented broadband integrated services digital networks ([[B-ISDN]], and its better-known supporting technology ATM) and connectionless [[IEEE 802.6]] switched multi-megabit data service ([[SMDS]]).

At any time there is information to be transmitted; the switch basically sends the data units. Connections don't have to be negotiated like circuit switching. Channels don't have to be allocated because channels do not exist in ATM, and on condition that there is an adequate amount of bandwidth to maintain it, there can be indefinite transmissions over the same facility.

Cell relay utilizes data cells of a persistent size. Frames are comparable to data packets; however they contrast from cells in that they may fluctuate in size based on circumstances. This type of technology is not secure for the reason that its procedures do not support error handling or data recovery. Per se, all delicate and significant transmissions may perhaps be transported faster via fixed-sized cells, which are simpler to transmit compared to variable-sized frames or packets.