Setting Link Layer Attributes for a Synchronous Serial Interface

Procedure

1. Run system-view

   The system view is displayed.

2. Run interface serial interface-number

   The serial interface view is displayed.

3. Run physical-mode sync

   The serial interface is configured to work in synchronous mode.

   By default, a serial interface works in synchronous mode.

4. Set the link layer protocol of the synchronous serial interface.

   • Run link-protocol ppp

     PPP is configured as the link layer protocol of the synchronous serial interface.

   • Run link-protocol fr [ ietf | nonstandard ]

     FR is configured as the link layer protocol of the synchronous serial interface.

   • Run link-protocol hdlc

     HDLC is configured as the link layer protocol of the synchronous serial interface.

   • Run link-protocol x25 [ dte | dce ] [ ietf | nonstandard ]

     The X.25 protocol is configured as the data link layer protocol of the interface.

   • Run link-protocol lapb [ dte | dce ] [ ip | multi-protocol ]

     LAPB is configured as the data link layer protocol of the interface.

     The default link layer protocol of a synchronous serial interface is PPP.

5. Run code { nrz | nrzi }

   The encoding and decoding mode is set for the synchronous serial interface.

   The default encoding and decoding mode of a synchronous serial interface is NRZ.

6. Run crc { 16 | 32 | none }

   The CRC check mode is set for the synchronous serial interface.

   By default, a synchronous serial interface uses the 16-bit CRC check mode.

7. Run idlecode { 7e | ff }

   The line idle code is set for the synchronous serial interface.

   By default, a synchronous serial interface uses the line idle code 0x7e.

8. Run itf number number

   The number of interframe filling tags is set for the synchronous serial interface.

   By default, the number of interframe filling tags of a synchronous serial interface is 4.

9. Run mtu mtu

   The MTU is set for the synchronous serial interface.

   The default MTU of a synchronous serial interface is 1500 bytes.