Dell PowerConnect 8100 User's Configuration Guide - Page 66

Protected Ports (Private VLAN Edge) Private VLAN Edge (PVE) ports are a Layer 2 security feature that provides port-based security between ports that are members of the same VLAN. It is an extension of the common VLAN. Traffic from protected ports is sent only to the uplink ports and cannot be sent to other ports within the VLAN. For information about configuring IPSG, see "Configuring Port-Based Traffic Control" on page 679. Switching Features Flow Control Support (IEEE 802.3x) Flow control enables lower speed switches to communicate with higher speed switches by requesting that the higher speed switch refrains from sending packets. Transmissions are temporarily halted to prevent buffer overflows. For information about configuring flow control, see "Configuring Port-Based Traffic Control" on page 679. Head of Line Blocking Prevention Head of Line (HOL) blocking prevention prevents traffic delays and frame loss caused by traffic competing for the same egress port resources. HOL blocking queues packets, and the packets at the head of the queue are forwarded before packets at the end of the queue. Alternate Store and Forward (ASF) The Alternate Store and Forward (ASF) feature reduces latency for large packets. When ASF is enabled, the memory management unit (MMU) can forward a packet to the egress port before it has been entirely received on the Cell Buffer Pool (CBP) memory. AFS, which is also known as cut-through mode, is configurable through the command-line interface. For information about how to configure the AFS feature, see the CLI Reference Guide available at support.dell.com/manuals. 66 Switch Features