3com MSR 20-20 참조 매뉴얼

Synchronous serial interface view

None

Use the idle-mark command to configure the idle-time encoding scheme of the 
synchronous serial interface to be 0xFF.

Use the undo idle-mark command to restore the default setting.

By default, the synchronous serial interface uses “0x7E” to indicate its idle state.

While most SDLC devices use “0x7E” (flags) to indicate “idle” space between 
frames, some other SDLC devices use “0xFF” (marks) for this indication. For 
compatibility with different types of devices, you can configure the router to send 
either flags (default) or marks to indicate its idle state. When the synchronous 
serial interface is connected with an AS/400 device, you need to change the 
idle-time encoding scheme by using this command to improve the speed of polling 
the AS/400 device.

# Configure synchronous serial interface Serial 2/0 to send 0xFF to indicate idle 
space between frames.

<Sysname> system-view

[Sysname] interface serial 2/0

[Sysname-Serial2/0] idle-mark 

Synchronous serial interface view

None

Use the link-protocol sdlc command to configure the synchronous serial 
interface to use SDLC as link layer encapsulation protocol.

By default, the default link layer protocol is PPP.

For SNA, SDLC is a link layer protocol, working very similarly as HDLC. To ensure 
that DLSw works normally, you need to enable SDLC as the link layer 
encapsulation protocol on the synchronous serial interface.