2Outline Overview What Applications Are Used with MPLS? What Is Unicast IP Routing?What Is Multicast IP Routing?What are MPLS VPNs?What Is MPLS TEWhat Is MPLS QoS?What is AToM?What Are the Interactions Between MPLS Applications?SummaryLesson Aim<Enter lesson aim here.>
3MPLS Applications MPLS is already used in many different applications: Unicast IP routingMulticast IP routingMPLS TEQoSMPLS VPNs (course focus)AToM
4MPLS Unicast IP Routing Basic MPLS service supports unicast IP routing.MPLS unicast IP routing provides enhancement over traditional IP routing.The ability to use labels for packet forwarding:Label-based forwarding provides greater efficiency.The FEC corresponds to a destination address stored in the IP routing table.Labels support connection-oriented services.The capability to carry a stack of labels assigned to a packet:Label stacks allow implementation of enhanced applications.
5MPLS Multicast IP Routing MPLS can also support multicast IP routing:A dedicated protocol is not needed to support multicast traffic across an MPLS domain.Cisco Protocol Independent Multicast Version 2 with extensions for MPLS is used to propagate routing information and labels.The FEC is equal to a destination multicast address stored in the multicast routing table.
6MPLS VPNsMPLS VPNs are highly scaleable and support IP services such as:MulticastQuality of QoSTelephony support within a VPNCentralized services including content and web hosting to a VPNNetworks are learned via an IGP from a customer or via BGP from other MPLS backbone routers.Labels are propagated via MP-BGP. Two labels are used:The top label points to the egress router.The second label identifies the outgoing interface on the egress router or a routing table where a routing lookup is performed.FEC is equivalent to a VPN site descriptor or VPN routing table.
7MPLS TE MPLS TE supports constraints-based routing MPLS TE enables the network administrator toControl traffic flow in the networkReduce congestion in the networkMake best use of network resourcesMPLS TE requires OSPF or ISIS with extensions to hold the entire network topology in their databases.OSPF and IS-IS should also have some additional information about network resources and constraints.RSVP is used to establish TE tunnels and to propagate labels.
8MPLS QoSMPLS QoS provides differentiated types of service across an MPLS network.MPLS QoS offers:Packet classificationCongestion avoidanceCongestion management.MPLS QoS is an extension to unicast IP routing that provides differentiated services.Extensions to LDP are used to propagate different labels for different classes.The FEC is a combination of a destination network and a class of service.
9Any Transport over MPLS AToM transports Layer 2 traffic over an IP or MPLS backbone.AToM accommodates many types of Layer 2 frames, including Ethernet, Frame Relay, ATM, PPP, and HDLC.AToM enables connectivity between existing data link layer (Layer 2) networks by using a single, integrated, packet-based network infrastructure.AToM forwarding uses two-level labels.AToM also offers performance, scalability, and other MPLS enhancements such as TE, fast reroute, and QoS.
10Examples of AToM Ethernet over MPLS (EoMPS) ATM over MPLS Supports the transport of Ethernet frames across an MPLS core for a particular Ethernet or virtual LAN (VLAN) segmentApplications include TLS and VPLSATM over MPLSSupports two types of transport mechanisms of ATM frames across an MPLS core:AAL5-over-MPLS modeCell-relay modeFrame Relay over MPLSSupports transport of Frame Relay packets over MPLS coreCarries BECN, FECN, DE, and C/R in a control word header
12SummaryMPLS is used in many applications: unicast IP routing, multicast IP routing, MPLS VPNs, MPLS TE, QoS, and AToM.Basic MPLS provides unicast IP routing using an IP routing protocol and a label distribution protocol.MPLS multicast IP routing does not need a dedicated protocol to support multicast traffic across an MPLS domain.MPLS VPNs provide highly scaleable VPNs providing IP services.MPLS TE supports constraints-based routing.MPLS QoS extends unicast IP routing and provides differentiated services.AToM transports Layer 2 traffic over an IP or MPLS backbone.Some MPLS applications may use a different routing and label exchange protocol; however, the applications all use the same label-forwarding engine.