Configure X.25
201
X.25 protocol can multiplex multiple virtual connection over a real physical link
between DTE and DCE, also called virtual circuit (VC) or logical channel (LC). X.25
can establish up to 4095 virtual connections numbered from 1 to 4095. The
number that can be employed to identify each virtual circuit (or logical channel) is
called logical channel identifier (LCI) or virtual circuit number (VCN).
Strictly speaking, virtual circuit and logical channel are two different concepts.
However, they are not much different at the user side.
X.25 protocol divides the logical channel into 4 areas. (listed here in numerically
increasing order): Permanent virtual circuits (PVCs), Incoming-only circuits,
Two-way circuits, Outgoing-only circuits.
According to the X.25 recommendation proposed by ITU-T, DCE selects an
available logical channel with a smaller number from the “one-way incoming call
channel range” and “two-way channel range” to initiate a call, while DCE selects
an available logical channel with a larger number from the “one-way incoming call
channel range” and “two-way channel range” to initiate a call. Thus, we can
avoid the case that one side of the communication occupies all the channels, and
minimize the possibility of call collision.
In X.25 protocol, six parameters are employed to delimit the four sections, as
shown in the diagram below.
Figure 62
X.25 channel delimitation
For the meanings of these six parameters, please refer to the following table.
Table 236
X.25 channel delimitation parameters
Perform the following task in the interface view:
Parameter
Meaning
LIC
Lowest Incoming-only Channel
HIC
Highest Incoming-only Channel
LTC
Lowest Two-way Channel
HTC
Highest Two-way Channel
LOC
Lowest Outgoing-only Channel
HOC
Highest Outgoing-only Channel
1
LTC
LIC
HTC
HIC
LOC
HOC
4095
Permanent virtual circuit
Incoming-only channel
Unused
Two-way channel
Unused
Outgoing-only channel
Unused
Содержание 3036
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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 ...
Страница 34: ...30 ...
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 ...
Страница 248: ...244 CHAPTER 16 CONFIGURING LAPB AND X 25 ...
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 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 ...
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Страница 649: ...X RELIABILITY Chapter 45 Configuring a Standby Center Chapter 46 Configuring VRRP ...
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