The router supports IP/PPP on the channelized T3, E1, and T3/E3 interfaces and IP/PPP/SONET on the OC3/STM1 and OC12/STM4 interfaces. This support allows service providers to accept traffic from subscribers who have CPE equipment, such as routers with PPP interfaces, and to transmit traffic in PPP format to other network devices.
Figure 16 shows that the router supports the incoming IP/PPP traffic from the CPE. This traffic can then be routed to the uplink(s) attached to the router or to other CPEs that are attached to the router.
Figure 16: IP/PPP Connections from the CPE on an E-series Router
As shown in Figure 17, the PPP protocol can exist directly on top of the HDLC layer or on top of a layer 2 Frame Relay or ATM interface. In either case, IP rides on top of PPP, providing support for IP/PPP/ATM, IP/PPP/HDLC, and IP/PPP/Frame Relay. Both SONET and DSx/Ex interfaces are supported at the physical layer.
Figure 17: Structure of PPP
Figure 18 shows sample configuration parameters for PPP on a serial interface.
Figure 18: PPP Interface Configuration Parameters
The following sample command sequence configures PPP on a serial interface. See JUNOSe Link Layer Configuration Guide, for details.
- host1(config)#interface serial 3/0:2/5
- host1(config-if)#encapsulation ppp
- host1(config-if)#ip address 192.32.22.10 255.255.255.0
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