3Com SUPERSTACK 3 3250, Implementation Manual

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14 C
HAPTER
1: S
WITCH
F
EATURES
O
VERVIEW
Aggregated Links Aggregated links are connections that allow devices to communicate
using multiple links in parallel. Your Switch supports one aggregated link
using the two 10/100/1000 and SFP ports (25-26 on the Switch 3225,
49-50 on the Switch 3250). Aggregated links provide two benefits:
■
They can potentially increase the bandwidth of a connection.
■
They can provide redundancy — if one link is broken, the other link
will still pass traffic.
The Switch implements the IEEE 802.3ad standard for link aggregation.
For more information about aggregated links, see Chapter 2 “Optimizing
Bandwidth” .
Auto-negotiation Auto-negotiation allows ports to auto-negotiate port speed,
duplex-mode (only at 10 Mbps and 100 Mbps) and flow control. When
auto-negotiation is enabled (default), a port “advertises” its maximum
capabilities — these capabilities are by default the parameters that
provide the highest performance supported by the port.
SFP ports do not support auto-negotiation of port speed.
Ports operating at 1000 Mbps only support full duplex mode.
For details of the auto-negotiation features supported by your Switch,
please refer to the Management Quick Reference Guide that
accompanies your Switch.
Auto MDI/MDI-X
Auto MDI/MDI-X allows ports to detect whether they are connected to a
computer or another switch and configure themselves accordingly. This
eliminates the need for crossover cables.
Duplex
Full duplex mode allows packets to be transmitted and received
simultaneously and, in effect, doubles the potential throughput of a link.
Flow Control
All Switch ports support flow control, which is a mechanism that
minimizes packet loss during periods of congestion on the network.