ncurred when a packet is delivered from one port to another. However, errors are detected through the examination of the CRC (cyclic redundancy check) bits at the end of a packet. Although cut-through switching adds virtually no delay, retransmission of a packet is sometimes necessary after it reaches its destination, which consumes network bandwidth. Store-and-forward switching receives the entire frame into a buffer before forwarding it to the destination port. In this approach, the entire packet is checked before it is passed to its destination port. Although this method is highly reliable in terms of detecting and dealing with errors, it introduces a small amount of latency. Most store-and-forward switches comply with the Spanning Tree algorithm that discovers the best path to each destination and stores it in a look-up table. Subsequent packets that arrive for the same MAC address are sent out through the port specified in the table. Administrators can also use the table to create a redundant physical network for security. Kalpana (which means imagination in Hindi) pioneered the concept of Ethernet switching in 1990. According to the results of a 1996 study performed by the Dell'Oro Group, U.S. switching/wiring hub revenues were $3.9 billion in 1994. In 1995, they grew to $6.1 billion, and they have not looked back since. Given the advent of higher-layer switching (predominantly layer-3), store-and- forward switching is no longer much of an issue. Layer-3 switching is really wire-speed routing. So-called non-blocking switches execute routing in silicon rather than in software. By also offering backplanes with bandwidth capabilities that exceed the aggregate bandwidth of all ports, some manufacturers mitigate the non-deterministic nature of Ethernet's collision-detection based architecture. Video Communications: The Whole Picture EIA/TIA 568a Cable plant plays a big role in allowing Ethernet to run at 100 Mbps speeds. In 1991, the Electronics Industries Association and Telecommunications Industry Association 