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
Summary of Contents for Router 3032
Page 1: ...http www 3com com 3Com Router Configuration Guide Published March 2004 Part No 10014299...
Page 4: ...VPN 615 RELIABILITY 665 QOS 681 DIAL UP 721...
Page 6: ...2 ABOUT THIS GUIDE...
Page 7: ...I GETTING STARTED Chapter 1 3Com Router Introduction Chapter 2 3Com Router User Interface...
Page 8: ...4...
Page 16: ...12 CHAPTER 1 3COM ROUTER INTRODUCTION...
Page 34: ...30...
Page 60: ...56 CHAPTER 3 SYSTEM MANAGEMENT...
Page 98: ...94 CHAPTER 6 DISPLAY AND DEBUGGING TOOLS...
Page 110: ...106...
Page 114: ...110 CHAPTER 8 INTERFACE CONFIGURATION OVERVIEW...
Page 158: ...154 CHAPTER 10 CONFIGURING WAN INTERFACE...
Page 168: ...164...
Page 188: ...184 CHAPTER 13 CONFIGURING PPPOE CLIENT...
Page 192: ...188 CHAPTER 14 CONFIGURING SLIP Router ip route static 0 0 0 0 0 0 0 0 10 110 0 1...
Page 248: ...244 CHAPTER 16 CONFIGURING LAPB AND X 25...
Page 320: ...316...
Page 330: ...326 CHAPTER 20 CONFIGURING IP ADDRESS...
Page 362: ...358 CHAPTER 21 CONFIGURING IP APPLICATION...
Page 374: ...370 CHAPTER 23 CONFIGURING IP COUNT...
Page 406: ...402 CHAPTER 25 CONFIGURING DLSW...
Page 408: ...404...
Page 452: ...448 CHAPTER 29 CONFIGURING OSPF...
Page 482: ...478 CHAPTER 30 CONFIGURING BGP...
Page 494: ...490 CHAPTER 31 CONFIGURING IP ROUTING POLICY...
Page 502: ...498...
Page 508: ...504 CHAPTER 33 IP MULTICAST...
Page 514: ...510 CHAPTER 34 CONFIGURING IGMP...
Page 526: ...522 CHAPTER 36 CONFIGURING PIM SM...
Page 528: ...524...
Page 532: ...528 CHAPTER 37 CONFIGURING TERMINAL ACCESS SECURITY...
Page 550: ...546 CHAPTER 38 CONFIGURING AAA AND RADIUS PROTOCOL...
Page 590: ...586 CHAPTER 40 CONFIGURING IPSEC...
Page 599: ...IX VPN Chapter 42 Configuring VPN Chapter 43 Configuring L2TP Chapter 44 Configuring GRE...
Page 600: ...596...
Page 638: ...634 CHAPTER 43 CONFIGURING L2TP...
Page 649: ...X RELIABILITY Chapter 45 Configuring a Standby Center Chapter 46 Configuring VRRP...
Page 650: ...646...
Page 666: ...662...
Page 670: ...666 CHAPTER 47 QOS OVERVIEW...
Page 700: ...696 CHAPTER 49 CONGESTION MANAGEMENT...
Page 706: ...702 CHAPTER 50 CONGESTION AVOIDANCE...
Page 707: ...XII DIAL UP Chapter 51 Configuring DCC Chapter 52 Configuring Modem...
Page 708: ...704...
Page 762: ...758 CHAPTER 52 CONFIGURING MODEM...