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Software Features Explained
23
Flow Control
All the ports on your Switch support flow control, which is a congestion
control mechanism. Congestion is caused by one or more devices sending
traffic to an already overloaded port on the Switch. Flow control prevents
packet loss and inhibits the devices from generating more packets until
the period of congestion ends.
Flow control is implemented in two ways:
■
IEEE 802.3x standard for ports operating in full duplex.
■
Intelligent Flow Management (IFM), a 3Com proprietary method of
flow control, for ports operating in half duplex. IFM should only be
enabled if the port is connected to another switch, or an endstation. If
the port is connected to a repeated segment with local traffic, IFM
should be disabled.
For information about enabling flow control on a port, see
“Configuring
a Port”
on
page 59
.
Traffic Prioritization
Your Switch supports IEEE 802.1p traffic prioritization, which allows data
that has been assigned a high priority to be forwarded through the
Switch without being obstructed by other data. The system works by
using the multiple traffic queues that are present in the hardware of the
Switch — high priority traffic is forwarded on a different queue from
other traffic, and it is always given preference over the other traffic.
Traffic prioritization can be useful for critical applications that require a
high Class of Service (CoS) from the network. This could include:
■
Financial applications
— Accounts departments that need
immediate access to large files and spreadsheets at the end of the
month.
■
CAD/CAM design applications
— Design departments that need
priority connections to server farms and other devices for transferring
large files.
■
Converged network applications
— Organizations with a
converged network (that is, a network that uses the same
infrastructure for voice data and traditional data) that require high
quality voice data transmission at all times.
Summary of Contents for SuperStack II
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Page 154: ...154 CHAPTER 4 WORKING WITH THE COMMAND LINE INTERFACE ...
Page 156: ......
Page 162: ...162 CHAPTER 5 PORT TRUNKS ...
Page 169: ...VLANs and Your Switch 169 Figure 32 Forwarding unknown 802 1Q tags ...
Page 173: ...VLAN Configuration for Beginners 173 Figure 34 Simple example Untagged connections using hubs ...
Page 180: ...180 CHAPTER 6 VIRTUAL LANS VLANS ...
Page 188: ...188 CHAPTER 7 FASTIP ...
Page 200: ...200 CHAPTER 9 SPANNING TREE PROTOCOL Figure 49 STP configurations ...
Page 210: ...210 CHAPTER 10 RMON ...
Page 211: ...IV PROBLEM SOLVING Chapter 11 Problem Solving ...
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Page 224: ...224 CHAPTER 11 PROBLEM SOLVING ...
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