Configuring an ISDN BRI Interface
The ISDN BRI interface configuration includes maximum transmission unit (MTU), interface description, and the link layer protocol.
Pre-configuration Tasks
Before configuring an ISDN BRI interface, complete the following task:
Install a 1BST interface card on the router and ensure that it is registered successfully.
Context
Before configuration, clarify the following points:
- The interface provided by the ISP is an ISDN BRI U interface or an ISDN BRI S/T interface. The 1BST interface card supported by the device provides an ISDN BRI S/T interface.
- Whether the applied ISDN service supports digital services. The ISDN network supports digital or voice services. Devices communicate in digital format. Therefore, the applied ISDN service must provide digital services; otherwise, the devices cannot communicate.
Procedure
- Run system-view
The system view is displayed.
- Run interface bri interface-number
The ISDN BRI interface view is displayed.
- Run mtu mtu
The MTU of the ISDN BRI interface is set.
By default, the MTU of an ISDN BRI interface is 1500 bytes.
- (Optional) Run description description
A description is configured for the ISDN BRI interface.
- Run either of the following commands to configure a link layer protocol for the ISDN BRI interface:
- Run link-protocol ppp
PPP is configured as the link layer protocol of the interface.
- Run link-protocol fr [ ietf | nonstandard ]
FR is configured as the link layer protocol of the interface.
By default, the link layer protocol of an ISDN BRI interface is PPP.
- Run link-protocol ppp