# Configuring Physical Layer Interfaces

The router supports a number of line rates; some of these are listed per line module below.

- COCX-F3 line module supports unchannelized E3.
- Channelized OCx/STMx (cOCx/STMx) line module supports DS3 channelized to DS1, fractional DS1, or the DS0 level; unchannelized DS3; E1/T1 channelized to fractional DS1; unframed E1.
- CT3 12-F0 line modules support DS3 channelized to DS1, fractional DS1, or the DS0 level. CT3 12-F0 line modules also support unchannelized T3.
- IPSec Service module provides tunnel service for secure tunnels.
- GE/FE line module supports Gigabit Ethernet and Fast Ethernet.
- GE-2 line module and GE-HDE line module support Gigabit Ethernet.
- OCx/STMx ATM line module supports OC3/STM1 ATM, OC12/STM4 ATM, and unchannelized T3.
- OCx/STMx POS line module supports OC3/STM1 POS and OC12/STM4 POS.
- OC48 line module supports OC48/STM16 POS.
- OC3/STM1 GE/FE line module supports OC3/STM1 ATM and Gigabit Ethernet.
- ES2 4G line module (LM) supports OC48/STM16 POS, OC12/STM1 POS, OC3/STM1 ATM, OC12/STM1 ATM, Gigabit Ethernet, 10-Gigabit Ethernet, and tunnel-service interfaces.
- ES2 10G Uplink LM, ES2 10G LM, and ES2 10G ADV LM supports 10-Gigabit Ethernet interfaces.
- COCX-F3 line module supports unchannelized T3.
- Service Module (SM) provides tunnel service for IP tunnels and LNS termination.

A variety of protocols are supported over these interfaces, including IP/Frame Relay, IP/ATM, IP/PPP, as well as the protocols to enable B-RAS services. The router’s DSx and E1/E3 implementations support termination, statistics gathering, alarm surveillance, and performance monitoring. These links can be used for either network ingress or network egress.

Figure 4: E Series Router Support for Fractional T1/E1 Through T3/E3 Interfaces

As shown in Figure 4, the router can support fractional, full, and channelized interfaces.

| Note: See ERX Hardware Guide, Chapter 4, Installing Modules and E120 and E320 Hardware Guide, Chapter 4, Installing Modules, for a discussion of slot groups and modules. See the ERX Module Guide and the E120 and E320 Module Guide , for a discussion of the combination of line modules allowed in E Series routers.

## Line Module Features

The following features are supported by the system line modules:

- Three different clocking options: internal timing, loop timing, and chassis timing
- DS3 framing type—Both M23 framing and C-bit parity
- DS1 framing type—Both D4 framing mode and ESF framing mode
- DS3 loopback—For line, payload, diagnostic, and DS1 loopbacks
- DS1 loopback—For line, payload, and diagnostic loopbacks
- DS3/DS1 line status/alarm monitoring
- DS1 line coding type—Both AMI line encoding and B8ZS line encoding
- Unique IP interface support—For each PPP or Frame Relay PVC interface

## Configurable HDLC Parameters

The following HDLC parameters are configurable:

- Mapping of DS0 timeslots for T1/FT1 DS0 mapping
- Setting the speed of the DS0 to Nx56 or Nx64
- HDLC CRC checking (enable/disable)
- HDLC CRC algorithm (CRC16 or CRC32)
- Channel data inversion (enable/disable)
- Maximum receive unit (MRU)
- Maximum transmit unit (MTU)

Statistics are also gathered per line module.

## Configuring Channelized T3 Interfaces

There12 T3 controllers available on each CT3 12-F0 line module. When you configure these T3 controllers, you are actually configuring T3 (DS3) lines. Each T3 controller has, by definition, 28 T1 controllers representing T1 (DS1) lines.

Use the T3 and T1 commands described in JunosE Physical Layer Configuration Guide, to:

- Specify the line characteristics, such as framing format and clock source, for T3s and associated T1s.
- Assign full and fractional T1 channels (DS0) to a virtual channel.

Figure 5 shows sample parameters for a channelized T3 interface configuration.

Figure 5: Channelized T3 Interface Configuration Parameters

The following sample command sequence configures a serial interface for a
CT3 12-F0 module. See JunosE Physical Layer Configuration Guide, for details.

host1(config)#controller t3 0/1 host1(config-controll)#framing c-bit host1(config-controll)#clock source line host1(config-controll)#cablelength 220 host1(config-controll)#t1 2/1 host1(config-controll)#t1 2 framing esf host1(config-controll)#t1 2 lineCoding b8zs host1(config-controll)#t1 2/1 timeslots 2/1 1,3-8,10-12 host1(config-controll)#interface serial 0/1:2/1

## Configuring T3 and E3 Interfaces

The COCX-F3 line module supports the following wide area network (WAN) protocol encapsulations:

- IP over PPP
- IP over ATM
- IP over PPP over ATM
- IP over PPP over PPPoE over ATM
- IP over Frame Relay

Figure 6 shows sample configuration parameters for a T3 interface configuration.

Figure 6: T3 Interface Configuration Parameters

The following sample command sequence configures a serial interface for a T3 module. See JunosE Physical Layer Configuration Guide, for details.

host1(config)#controller t3 0/1 host1(config-controll)#framing m23 host1(config-controll)#cablelength 300 host1(config-controll)#ds3-scramble host1(config-controll)#exit host1(config)#interface serial 0/1 host1(config-if)#invert data host1(config-if)#mtu 1600 host1(config-if)#mru 1600

## Configuring OCx/STMx and OC48 Interfaces

The router supports IP/ATM, IP/Frame Relay, and IP/PPP over SONET on the OCx/STMx interfaces. OC48 interfaces support IP/Frame Relay and IP/PPP over SONET, but do not support ATM operation. This interface support allows service providers to accept incoming optical connections or connect the router to the backbone network through optical connections. The router’s SONET implementation supports termination, statistic gathering, and alarm surveillance at the section, line, and path layers of a SONET interface.

Figure 7: SONET Interfaces

The following sample command sequence configures POS for an OC3 interface. See JunosE Link Layer Configuration Guide, for details.

host1(config)#interface pos 0/1 host1(config-if)#encapsulation ppp host1(config-if)#clock source internal module host1(config-if)#loopback line host1(config-if)#pos framing sdh host1(config-if)#mtu 1600 host1(config-if)#mru 1600 host1(config-if)#pos scramble-atm

## Configuring Channelized OCx/STMx Line Interfaces

The cOCx/STMx modules are generally used for circuit aggregration on the router. These line modules support the following controllers over OC3/STM1 or OC12/STM4, depending on the I/O module used with the line module:

- Fractional T1/E1 over SONET/SDH virtual tributaries or T3
- Unframed E1
- Unchannelized DS3

Figure 8 shows the configuration parameters for a sample T1 over DS3 interface configuration.

Figure 8: Parameters for T1 over DS3 Interface Configuration

The following sample command sequence configures T1 over DS3 on a channelized SONET interface as described in Figure 8. See JunosE Physical Layer Configuration Guide, for details.

host1(config)#controller sonet 3/0 host1(config-controller)#path 12 oc1 4/1 host1(config-controller)#path 12 ds3 1 channelized host1(config-controller)#path 12 ds3 1 t1 4 host1(config-controller)#path 12 ds3 1 t1 4/2 timeslots 1, 3-8, 10-12 host1(config)#interface serial 3/0:12/1/4/2

## Configuring Ethernet Interfaces

Ethernet interfaces support IP, PPPoE, multinetting (multiple IP addresses), and VLANs (subinterfaces). Ethernet modules use the Address Resolution Protocol (ARP) to obtain MAC addresses for outgoing Ethernet frames and support quality of service (QoS) classification. See JunosE Physical Layer Configuration Guide, for a description of limitations of individual modules.

Use the Fast Ethernet, Gigabit Ethernet, and 10-Gigabit Ethernet commands described in JunosE Physical Layer Configuration Guide to:

- Configure with IP only, with PPPoE only, with both IP and PPPoE, and with or without VLANs.
- Specify the line speed and duplex mode.
- Specify the MTU.

The following sample command sequence configures an IP interface on a VLAN on an Ethernet interface:

host1(config)#interface fastEthernet 2/0 host1(config-if)#encapsulation vlan host1(config-if)#interface fastEthernet 2/0.1 host1(config-if)#vlan id 201 host1(config-if)#ip address 192.168.129.5 255.255.255.0

The following sample command sequence adds an IP interface over PPPoE to the same VLAN:

host1(config)#interface fastEthernet 2/0.1.2 host1(config-if)#encapsulation pppoe host1(config-if)#interface fastEthernet 2/0.1.2.1 host1(config-if)#encapsulation ppp host1(config-if)#ip address 192.2.2.1 255.255.255.0

## Configuring IPSec-Service Interfaces

IPSec Service modules support interfaces associated with secure IP tunnels. You configure and delete these interfaces statically; however, the router assigns tunnels to the interfaces dynamically. This mechanism means that you must manage the interfaces for tunnels manually; however, the router will add and remove tunnels when required.

For information about configuring secure IP interfaces, see JunosE IP Services Configuration Guide . For information about managing IPSec service interfaces, see JunosE Physical Layer Configuration Guide.

## Configuring Tunnel Service Interfaces

You can configure both dynamic tunnels associated with L2TP and static IP tunnels on your E Series router; however, you must first install a Service Module (SM). Dynamic tunnels, which are not associated with a particular interface, are described in JunosE Broadband Access Configuration Guide. Static tunnels, in which the tunnel is assigned to a particular interface and specified in slot/port format, are described in JunosE IP Services Configuration Guide.

For information about managing these types of tunnels on the router, see JunosE Physical Layer Configuration Guide.