HP Surestore 64 Planning Guide - Page 19

• Low latency The latency is less than two microseconds between transmission of a frame at a source port to receipt of the frame at the corresponding destination port (with no port contention). • Local control Actions taking place at a device N_Port seldom affect operation of other ports, therefore servers need to maintain little or no information about other connected devices in a SAN. • Low communication overhead Fibre Channel protocol provides efficient use of transmission bandwidth, reduces interlocked handshakes across the communication interface, and efficiently implements low-level error recovery mechanisms. This results in little communication overhead in the protocol and a director bit error rate (BER) not exceeding one bit error per trillion (1012) bits. • Multiple topology support The director supports both point-to-point and multiswitch fabric topologies, and indirectly supports arbitrated loop topology. - Point-to-point topology provides a single direct connection between two device N_Ports. This topology supports bidirectional transmission between source and destination ports. Through dynamic switching, the director configures different point-to-point transmission paths. In all cases, connected N_Ports use 100%of the available bandwidth. - A multiswitch fabric topology provides the ability to connect directors (and other switch elements) through E_Ports and interswitch links (ISLs) to form a Fibre Channel fabric. Director elements receive data from a device and, based on the destination N_Port address, route the data through the fabric (and possibly through multiple switch elements) to the destination device. Director Overview 5 Introduction