66 Switch FeaturesSwitching FeaturesFlow Control Support (IEEE 802.3x)Flow control enables lower speed switches to communicate with higher speedswitches by requesting that the higher speed switch refrains from sendingpackets. Transmissions are temporarily halted to prevent buffer overflows.For information about configuring flow control, see "Configuring Port-BasedTraffic Control" on page 691.Head of Line Blocking PreventionHead of Line (HOL) blocking prevention prevents traffic delays and frameloss caused by traffic competing for the same egress port resources. HOLblocking queues packets, and the packets at the head of the queue areforwarded before packets at the end of the queue.Alternate Store and Forward (ASF)The Alternate Store and Forward (ASF) feature reduces latency for largepackets. When ASF is enabled, the memory management unit (MMU) canforward a packet to the egress port before it has been entirely received on theCell Buffer Pool (CBP) memory.AFS, which is also known as cut-through mode, is configurable through thecommand-line interface. For information about how to configure the AFSfeature, see theCLI Reference Guide available at support.dell.com/manuals.Jumbo Frames SupportJumbo frames enable transporting data in fewer frames to ensure lessoverhead, lower processing time, and fewer interrupts.For information about configuring the port MTU, see "Configuring PortCharacteristics" on page 491.Auto-MDI/MDIX SupportYour switch supports auto-detection between crossed and straight-throughcables. Media-Dependent Interface (MDI) is the standard wiring for endstations, and the standard wiring for hubs and switches is known as Media-Dependent Interface with Crossover (MDIX).
