Port-based features – Dell POWEREDGE M1000E User Manual
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Introduction
Port-Based Features
Jumbo Frames Support
Jumbo frames enable transporting identical data in fewer frames to ensure less overhead, lower
processing time, and fewer interrupts.
Auto-MDI/MDIX Support
Your switch supports auto-detection between crossed and straight-through cables.
Media-Dependent Interface (MDI) is the standard wiring for end stations, and the standard wiring for
hubs and switches is known as Media-Dependent Interface with Crossover (MDIX).
Auto Negotiation
Auto negotiation allows the switch to advertise modes of operation. The auto negotiation function
provides the means to exchange information between two switches that share a point-to-point link
segment, and to automatically configure both switches to take maximum advantage of their transmission
capabilities.
The PowerConnect M6220/M6348/M8024 enhances auto negotiation by providing port advertisement.
Port advertisement allows the system administrator to configure the port speeds advertised.
For information about auto negotiation, see "Port Configuration" or "LAG Configuration."
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 for ports or LAGs, see "Port Configuration" or "LAG
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.
Back Pressure Support
On half-duplex links, a receiver may prevent buffer overflows by occupying the link so that it is
unavailable for additional traffic.