3Com Router User Manual

10
CONFIGURING WAN INTERFACE
This chapter contains information on the following topics:
■WAN Interface Introduction
■Asynchronous Serial Interface
■AUX Interface
■Synchronous Serial Interface
■ISDN BRI Interface
■CE1/PRI Interface
■CT1/PRI Interface
■E1-F Interface
■T1-F Interface
■CE3 Interface
■CT3 Interface
WAN Interface 
IntroductionThe wide area network (WAN) can be divided into X.25 network, frame relay 
network, ATM network and ISDN network according to the line type. Accordingly, 
the router has...

118CHAPTER 10: CONFIGURING WAN INTERFACE
■Set the asynchronous serial interface to work in dialup or dedicated line mode
■Set link layer protocol
■Set baud rate
■Set link establishment mode
■Set the check mode in flow mode
■Set stop bit in flow mode
■Set data bit in flow mode
■Set flow control mode
■Enable or disable level detection
■Enable or disable internal loopback and external loopback
■Set MTU
■Setting the coding format of Modem
The asynchronous serial interface may also need to be configured with...

Asynchronous Serial Interface119
instructions in dialup mode. In dedicated line mode, ensure that modem 
command is not configured, i.e. disable dial with 
undo modem command. 
Please use the following commands in the view of asynchronous serial interface.
Ta b l e 96   Set the work mode of asynchronous serial interface 
The asynchronous serial interface works in dial mode by default, i.e. modem 
command is configured by default. Both calling in and calling out are allowed with 
modem in and modem out...

120CHAPTER 10: CONFIGURING WAN INTERFACE
Dedicated mode is usually used when asynchronous serial interfaces are directly 
connected.
■Flow: Also called the Interactive mode, which means two ends of the link 
interact with each other after the setup of a physical connection. The calling 
end sends configuration command to the receiving end (with the same effect 
as the user inputs configuration command remotely), sets working parameters 
of the link layer protocol at the receiving end and then establishes...

Asynchronous Serial Interface121
When the link establishment mode of async serial interface is flow or TTY, the two 
ends of the link will interact with each other after the setup of a physical 
connection. The calling end will send configuration command to the receiving end 
and set the interactive parameters of link layer protocol on the receiving end 
before the establishment of the link. In practical application (such as terminal 
server), the router will send configuration command to the terminal...

122CHAPTER 10: CONFIGURING WAN INTERFACE
Please use the following commands in the view of the asynchronous serial 
interface.
Ta b l e 104   Enable or disable the level detection for the asynchronous serial interface
By default the level detection is enabled for the asynchronous serial interface.
12Enable or disable internal loopback and external loopback
On performing special function test, the internal loopback and external loopback 
is enabled for the asynchronous serial interface. 
Please use...

Synchronous Serial Interface123
Configure AUX interface
1Enter AUX interface view
Perform the following configuration in the all views.
Ta b l e 108   Enter AUX interface view
2Configure AUX interface
The configuration of AUX interface is basically the same with that of common 
asynchronous serial interfaces. The following items should be noted:
aThe operating mode of AUX interface is Flow mode by default, and AUX 
interface work in dial mode by default.
bWhen the data bit is configured on AUX interface,...

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■Enable or disable level detection
■Enable or disable data carrier detection
■Setting the synchronous serial interface to work in full duplex or half duplex 
mode
■Enable or disable internal loopback/external loopback 
■Set MTU
■Set the time interval for sending keepalive packets
■Set the idle coding of synchronous serial interface
PPP/X.25/FR parameters, BDR parameters, IP address, firewall parameters and 
standby center parameters should be configured on the...

Synchronous Serial Interface125
Perform following commands in synchronous serial interface view.
Ta b l e 112   Set the digital signal encoding format of synchronous serial interface
By default, the digital signal encoding format of synchronous serial interface is 
NRZ.
5Set baud rate
Please use the following command in the view of the synchronous serial interface.
Ta b l e 113   Set the baud rate of synchronous serial interface 
When two synchronous serial interfaces are connected, the baud rate on line...

126CHAPTER 10: CONFIGURING WAN INTERFACE
TxClk stands for transmitting clock, RxClk for receiving clock, the clock before “=” 
is DTE-side clock, and that behind “=” is DCE-side clock.
Please use the following commands in the view of the synchronous serial 
interface. 
Ta b l e 115   Select work clock
The clock of DCE-side synchronous serial interface is dceclk by default, and that of 
DTE side is dteclk3 by default.
7Set clock inversion
In some special cases, the clock will generate half-period delay on...