Multi-protocol Label Switching Jiang Wu Computer Science Seminar 5400

Agenda Background – Routing in Internet Protocol (IP) Networks – Asynchronous Transfer Mode (ATM) – IP Over ATM Models Multi-protocol Label Switching (MPLS) MPLS using ATM Switching Feature Research Q & A

Traditional Routing In IP Networks H1 SourceDestinationData H2 H3 H4 H5 H6 H7 H8 DestinationNext Hop A.B.C.*Rn Routing Table R1 R5 R6 R7 R8 R4 R3 R2

Traditional Routing In IP Networks IP address Routing Algorithm – e.g. Open Shortest Path First (OSPF) Characteristics: – Connectionless – Hop-by-hop – IP Address Parsing at Each Hop – Routing Table Query at Each Hop

Traditional Routing In IP Networks Issues: CPU Speed: 10 times improvement per decade Data Communication: more than 100 times improvement per decade Routers become the bottlenecks of the Internet

ATM H1 H2 SETUP VPI/VCI VPI Table InOut PortVPIPortVPI VPI Table

H1 H2 RELEASE VPI Table ATM

ATM address Routing and Signaling – e.g. Private Network-to-Network Interface (P-NNI) Connection Oriented Cell Switch by hardware High speed

IP Over ATM Models Overlay Model Peer-to-Peer Model – MPLS

MPLS Architecture H1 H2 H4 H3 LSR LER MPLS Domain

MPLS Components Label Edge Router (LER) Label Switching Router (LSR) Forward Equivalence Class (FEC) Label Label-Switched Path (LSP) Label Distribution Protocol (LDP)

MPLS Component: LSR In the core of MPLS networks High-speed router Switch data traffic within MPLS domain

MPLS Component: LER At the edge of MPLS networks Assign and remove label Transport data traffic between MPLS domain and IP networks

MPLS Component: FEC Representation of a group of packets that share the same requirement for transport – e.g. packets with same destination IP address prefix

MPLS Component: Label Short fixed length identifier Assigned to every packet Carried in layer 2 header Of local significance

MPLS Component: LSP A path to transport packets within MPLS domain Set up prior to data transmission Unidirectional

MPLS Component: LDP Distribution label information to LSR

MPLS Operations Label creation and distribution Table creation at each router LSP creation Label insertion/table lookup Packet forwarding

Label creation and distribution H1 H2 H4 H3 LSR LER FECHopInLabel FECHopLabel LSP

Label Insert, Swap and Remove H1 H2 H4 H3 LSR LER FECHopInLabel FECHopLabel IP LabelIP LabelIP

MPLS IP address Routing Algorithm – Same as IP network LDP Support ATM, Frame Relay, …

MPLS using ATM InOut PortVPIPortVPI VPI Table Cell Switch Hardware OSPF, LDP ATM-LSR

Future Research ATM SONET IP WDM IP MPLS GMPLS

Q & A

Thanks