• Junos OS MPLS Applications Configuration Guide athttp://www.juniper.net/techpubs/software/junos/• Junos OS VPNs Configuration Guide at http://www.juniper.net/techpubs/software/junos/Understanding Junos OS MPLS Components for J-EX Series SwitchesJunos OS MPLS for J-EX Series Switches supports Layer 2 protocols and Layer 2 virtualprivate networks (VPNs). You can configure MPLS on J-EX Series switches to increasetransport efficiency in your network. MPLS services can be used to connect various sitesto a backbone network and to ensure better performance for low-latency applicationssuch as VoIP and other business-critical functions.This topic includes:• Provider Edge Switches on page 3059• Provider Switch on page 3060• Components Required for All Switches in the MPLS Network on page 3060• Family MPLS on page 3062Provider Edge SwitchesTo implement MPLS on J-EX Series switches, you must configure two provider edge (PE)switches—that is, an ingress (local) PE switch and an egress (remote) PE switch.The ingress switch (the entry point to the MPLS tunnel) receives an IP packet, analyzesit, and pushes an MPLS label onto it. This label places the packet in a forwardingequivalence class (FEC) and determines its handling and destination through the MPLStunnel. The egress provider edge switch (the exit point from the MPLS tunnel) pops theMPLS label off the outgoing packet.MPLS traffic is bidirectional. Therefore, each PE switch can be configured as both aningress switch and an egress switch, depending on the direction of the traffic.J-EX Series switches can handle only single-label MPLS packets. If a packet already hasan MPLS label, the PE switch removes the label and swaps it for another MPLS label.MPLS Protocol and Label Switched PathsEach PE switch must be configured to support the MPLS protocol, and the MPLS stanzamust include the configuration of a label-switched path (LSP) that specifies the addressof the remote PE switch.Junos OS MPLS for J-EX Series switches supports RSVP-based LSPs.Circuit Cross-Connect for Customer-Edge InterfacesYou can configure the customer-edge interfaces of the PE switches as a circuitcross-connect (CCC), to create a transparent connection between two circuits. Whenyou configure an interface as a CCC, the interface no longer belongs to a default VLAN.The interface becomes an MPLS tunnel — used exclusively for MPLS packets. You can3059Chapter 120: MPLS—Overview
