Configure the Encapsulation on a Physical Interface

By default, Point-to-Point Protocol (PPP) is the encapsulation type for physical interfaces. To configure the encapsulation on a physical interface, include the encapsulation statement at the [edit interfaces interface-name] hierarchy level:

[edit interfaces interface-name] 

encapsulation (atm-ccc-cell-relay | atm-pvc | cisco-hdlc | cisco-hdlc-ccc | cisco-hdlc-tcc |

ethernet-ccc | ethernet-over-atm | ethernet-tcc | ethernet-vpls | extended-vlan-ccc | 
extended-vlan-tcc | extended-vlan-vpls | frame-relay | frame-relay-ccc | frame-relay-tcc | 
multilink-frame-relay-uni-nni | ppp | ppp-ccc | ppp-tcc | vlan-ccc | vlan-vpls); 

The physical interface encapsulation can be one of the following:

• ATM Cell Relay—Connects two remote virtual circuits or ATM physical interfaces with a label-switched path (LSP). Traffic on the circuit is ATM cells.

You can configure an ATM 1 PIC to use cell-relay accumulation mode (CAM). In this mode, the incoming cells (1 to 8 cells) are packaged into a single packet and forwarded to the label-switched path (LSP). Cell-relay accumulation mode is not supported on ATM 2 PICs. You configure CAM as shown in the following example:

[edit chassis]

fpc 1 {

    pic 0 {

        atm-cell-relay-accumulation;

    }

}

For more information, see the JUNOS Internet Software Configuration Guide: Getting Started.

• ATM PVC—Defined in RFC 2684, Multiprotocol Encapsulation over ATM Adaptation Layer 5. When you configure physical ATM interfaces with ATM PVC encapsulation, an RFC 2684-compliant ATM Adaptation Layer 5 (AAL5) tunnel is set up to route the ATM cells over an MPLS path that is typically established between two MPLS-capable routers using the Label Distribution Protocol (LDP).
• Cisco HDLC—E1, E3, SONET, T1, and T3 interfaces can use Cisco HDLC encapsulation. Two related versions are supported:

• CCC version (cisco-hdlc-ccc)—The logical interfaces do not require an encapsulation statement. When you use this encapsulation type, you can configure the family ccc only.
• TCC version (cisco-hdlc-tcc)—Similar to CCC and has the same configuration restrictions, but used for circuits with different media on either side of the connection.

• Ethernet over ATM—Allows ATM interfaces to connect to devices that support only bridged-mode protocol data units (PDUs).
• Ethernet Cross-Connect—Ethernet interfaces without VLAN tagging can use Ethernet CCC encapsulation. Two related versions are supported:

• CCC version (ethernet-ccc)—Ethernet interfaces with standard Tag Protocol ID (TPID) tagging can use Ethernet CCC encapsulation. When you use this encapsulation type, you can configure the family ccc only.
• TCC version (ethernet-tcc)—Similar to CCC, but used for circuits with different media on either side of the connection. One-port Gigabit Ethernet, two-port Gigabit Ethernet, four-port Gigabit Ethernet, and four-port Fast Ethernet PICs can use Ethernet TCC encapsulation.

• VLAN Circuit Cross-Connect (CCC) (vlan-ccc)—Ethernet interfaces with virtual local area network (VLAN) tagging enabled can use VLAN CCC encapsulation. VLAN CCC encapsulation supports TPID 0x8100 only. When you use this encapsulation type, you can configure the family ccc only.
• Extended VLAN Cross-Connect—Gigabit Ethernet interfaces with virtual local area network (VLAN) 802.1Q tagging enabled can use extended VLAN cross-connect encapsulation. (Ethernet interfaces with standard TPID tagging can use VLAN CCC encapsulation.) Two related versions of extended VLAN cross-connect are supported:

• CCC version (extended-vlan-ccc)—Extended VLAN CCC encapsulation supports TPIDs 0x8100, 0x9100, and 0x9901. Extended VLAN CCC is not supported on four-port Gigabit Ethernet PICs. When you use this encapsulation type, you can configure the family ccc only.
• TCC version (extended-vlan-tcc)—Similar to CCC, but used for circuits with different media on either side of the connection. One-port Gigabit Ethernet, two-port Gigabit Ethernet, and four-port Fast Ethernet PICs can use Extended Ethernet TCC encapsulation.

• Ethernet VPLS (ethernet-vpls)—Ethernet interfaces with Virtual Private LAN Service (VPLS) enabled can use Ethernet VPLS encapsulation. For more information about VPLS, see the JUNOS Internet Software Configuration Guide: VPNs and the JUNOS Internet Software Feature Guide.
• Ethernet VLAN VPLS (vlan-vpls)—Ethernet interfaces with virtual local area network (VLAN) tagging and VPLS enabled can use Ethernet VLAN VPLS encapsulation. For more information about VPLS, see the JUNOS Internet Software Configuration Guide: VPNs and the JUNOS Internet Software Feature Guide.
• Extended VLAN VPLS (extended-vlan-vpls)—Ethernet interfaces with virtual local area network (VLAN) 802.1Q tagging and VPLS enabled can use Ethernet Extended VLAN VPLS encapsulation. (Ethernet interfaces with standard TPID tagging can use Ethernet VLAN VPLS encapsulation.) Extended Ethernet VLAN VPLS encapsulation supports TPIDs 0x8100, 0x9100, and 0x9901. For more information about VPLS, see the JUNOS Internet Software Configuration Guide: VPNs and the JUNOS Internet Software Feature Guide.
• Frame Relay—Defined in RFC 1490, Multiprotocol Interconnect over Frame Relay. E1, E3, link services, SONET, T1, and T3 interfaces can use Frame Relay encapsulation. Two related versions are supported:

• CCC version (frame-relay-ccc)—The same as standard Frame Relay for DLCIs 0 through 511. DLCIs 512 through 1022 are dedicated to CCC, and the logical interface must also have frame-relay-ccc encapsulation. When you use this encapsulation type, you can configure the family ccc only.
• TCC version (frame-relay-tcc)—Similar to Frame Relay CCC and has the same configuration restrictions, but is used for circuits with different media on either side of the connection.

• Multilink Frame Relay (MLFR) User-to-Network Interface (UNI) and Network-to-Network Interface (NNI) (multilink-frame-relay-uni-nni)—Link services interfaces functioning as FRF.16 bundles can use multilink Frame Relay UNI NNI encapsulation. This encapsulation is also used on link services interfaces' constituent T1, E1, or NxDS-0 interfaces.
• Point-to-Point Protocol (PPP)—Defined in RFC 1661, The Point-to-Point Protocol (PPP) for the Transmission of Multiprotocol Datagrams over Point-to-Point Links. PPP is the default encapsulation type for physical interfaces. E1, E3, SONET, T1, and T3 interfaces can use PPP encapsulation. Two related versions are supported:

• Circuit cross-connect (CCC) version (ppp-ccc)—The logical interfaces do not require an encapsulation statement. When you use this encapsulation type, you can configure the family ccc only.
• Translational cross-connect (TCC) version (ppp-tcc)—Similar to CCC and has the same configuration restrictions, but used for circuits with different media on either side of the connection.