200 CHAPTER 16: CONFIGURING LAPB AND X.25
Configure X.25
Interface The configuration of X.25 interface includes:
■Configure X.121 address
■Configure X.25 working mode
■Configure X.25virtual circuit range
■Configure X.25 modulo
■Configure X.25 default flow control parameter
Only when configured as an X.25 interface, can an interface transmit data with
X.25 protocol.
In the following configuration commands, only “Configure X.25 working mode” is
mandatory, and other configuration items are optional, depending on the specific
condition of X.25 network that is accessed.
1Configure X.121 address
If the 3Com Router series does not originate or terminate calls but only
participates in X.25 switching, there is no need to configure an X.121 address.
However, if the 3Com Router series is attached to a X.25 Network, you should
configure an X.121 address for the interface, and usually, the address is provided
by the ISP.
To set/cancel the X.121 address, perform the following task in interface view.
Tabl e 234 Set/Cancel the X.121 address of the interface
2Configure X.25 working mode
To configure X.25 working mode, perform the following task in the interface view.
Tabl e 235 Set X.25 working mode
Layer 3 of X.25 supported by 3Com Router series can work in both DTE mode and
DCE mode. It can also specify the datagram format among the two optional
formats: IETF and Nonstandard.
Note that generally speaking, public X.25 packet switching network requires the
router to access at DTE side and requires the IETF format. Therefore, the working
mode of X.25 should be DTE and the format should be IETF. If a pair of serial
interfaces of two routers is directly connected for data transmission, make sure the
two transmission ends are DTE and DCE and the formats are the same.
For X.25 supported by 3Com Router series, default working mode is DTE and
default format is IETF.
3Configure X.25 virtual circuit range
Operation Command
Set the X.121 address of the interface x25 x121-address
x.121-address
Cancel the set X.121 address of the interface undo x25 x121-address
Operation Command
Set the working mode and packet format of X.25
interface link-protocol x25 [ dte |
dce ] [ nonstandard | ietf ]