49
C
ONGESTION
M
ANAGEMENT
This chapter covers the following topics:
■
What is Congestion?
■
Congestion Management Policy Overview
■
Selecting Congestion Management Policies
■
Operating Principle of the Congestion Management Policies
■
Configuring Congestion Management
■
Congestion Management Configuration Examples
What is Congestion?
For a network unit, when the speed of the data packet is faster than the speed at
which this interface sends the data packet, congestion occurs on the interface. If
not enough memory space can be provided to store these data packets, some of
them will be lost. The loss of the data packet can cause the host or router that is
sending the data packet to resend this data packet because of a timeout which
can cause a communication failure.
There are many factors causing congestion. For example, when the data packet
flow enters the router through the high-speed link and is then transmitted
through the low speed link, congestion can occur. When the data packet flow
enters the router simultaneously from multiple interfaces and is transmitted from
one interface or the processor slows down, congestion may occur.
As shown in Figure 217, two LANs of one company are connected with each other
through the low speed link. When a user on LAN 1 sends a large number of data
packets to a user on LAN 2, it may cause congestion on the interface through
which router A of LAN 1 is connected to the low speed link. If an important
application is running between the servers of both LANs, while an unimportant
application is running between two PCs, the important application will be
influenced.
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Страница 1: ...http www 3com com 3Com Router Configuration Guide Published March 2004 Part No 10014299 ...
Страница 4: ...VPN 615 RELIABILITY 665 QOS 681 DIAL UP 721 ...
Страница 6: ...2 ABOUT THIS GUIDE ...
Страница 7: ...I GETTING STARTED Chapter 1 3Com Router Introduction Chapter 2 3Com Router User Interface ...
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Страница 16: ...12 CHAPTER 1 3COM ROUTER INTRODUCTION ...
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Страница 60: ...56 CHAPTER 3 SYSTEM MANAGEMENT ...
Страница 88: ...84 CHAPTER 5 CONFIGURING NETWORK MANAGEMENT RouterA interface ethernet 0 RouterA Ethernet0 rmon promiscuous ...
Страница 98: ...94 CHAPTER 6 DISPLAY AND DEBUGGING TOOLS ...
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Страница 114: ...110 CHAPTER 8 INTERFACE CONFIGURATION OVERVIEW ...
Страница 158: ...154 CHAPTER 10 CONFIGURING WAN INTERFACE ...
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Страница 188: ...184 CHAPTER 13 CONFIGURING PPPOE CLIENT ...
Страница 192: ...188 CHAPTER 14 CONFIGURING SLIP Router ip route static 0 0 0 0 0 0 0 0 10 110 0 1 ...
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Страница 292: ...288 CHAPTER 18 CONFIGURING HDLC Enable HDLC packet debugging debugging hdlc packet interface type number ...
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Страница 330: ...326 CHAPTER 20 CONFIGURING IP ADDRESS ...
Страница 362: ...358 CHAPTER 21 CONFIGURING IP APPLICATION ...
Страница 374: ...370 CHAPTER 23 CONFIGURING IP COUNT ...
Страница 406: ...402 CHAPTER 25 CONFIGURING DLSW ...
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Страница 452: ...448 CHAPTER 29 CONFIGURING OSPF ...
Страница 482: ...478 CHAPTER 30 CONFIGURING BGP ...
Страница 494: ...490 CHAPTER 31 CONFIGURING IP ROUTING POLICY ...
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Страница 508: ...504 CHAPTER 33 IP MULTICAST ...
Страница 514: ...510 CHAPTER 34 CONFIGURING IGMP ...
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Страница 532: ...528 CHAPTER 37 CONFIGURING TERMINAL ACCESS SECURITY ...
Страница 550: ...546 CHAPTER 38 CONFIGURING AAA AND RADIUS PROTOCOL ...
Страница 590: ...586 CHAPTER 40 CONFIGURING IPSEC ...
Страница 599: ...IX VPN Chapter 42 Configuring VPN Chapter 43 Configuring L2TP Chapter 44 Configuring GRE ...
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Страница 649: ...X RELIABILITY Chapter 45 Configuring a Standby Center Chapter 46 Configuring VRRP ...
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Страница 700: ...696 CHAPTER 49 CONGESTION MANAGEMENT ...
Страница 706: ...702 CHAPTER 50 CONGESTION AVOIDANCE ...
Страница 707: ...XII DIAL UP Chapter 51 Configuring DCC Chapter 52 Configuring Modem ...
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