1. MPLS Multiple Protocol Label Switching 2003/2/19

2. Key Terminology in MPLS FEC (Forwarding Equivalence Class) A group of IP packets which are forwarded in the same manner (e.g., over the same path, with the same priority and the same label) Label A short fixed length identifier (virtual circuit ID localized) which is used to identify a FEC Label Swapping Looking up the incoming label to determine the outgoing label, encapsulation and port Label Switched Path (LSP) Path through one or more LSRs for a particular FEC Label Switching Router (LSR) An MPLS capable router

3. MPLS Related Protocols Data forwarding Label encapsulation Label operations: PUSH, SWAP and POP Label distribution protocols Provide procedures by which one LSR informs another of the label/FEC binding Extensions to routing protocols Existing routing protocols can be extended to distribute traffic engineering information

4. What is a Label The label can be carried in a layer 2 header (e.g., ATM and frame relay) or in a “shim” that sits between the layer 2 header and IP (e.g., LAN and PPP) Exp: Experimental (3 bits) S: Bottom of label stack (1 bit) TTL: Time-To-Live (8 bits) PayloadIP“shim”Layer 2 Label value (20 bits)ExpSTTL 4 Octets

5. Data Forwarding Edge LSR (Ingress) Edge LSR (Egress) LSR Label IP LSR (Penultimate) PUSHPOPSWAP L2 header

6. Ingress and Transit Operation Port 1Port 4 Ingress LSR LSR Port 2Port 3 FEC Output 10.60.0.0/16 port 4 PUSH label 40 To: 10.60.30.4 InputOutput port 2 label 40port 3 SWAP label 45 Label: 40 Label: 45

7. Textbook: MPLS and Label Switching Networks By Uyless Black Ref: MPLS Technology and Application by Bruce Davie, Yakov Rekhter Ietf documents IEEE communication and network magazines Papers

8. Assignment #1 and #2 Home work #1 List the Features of IP Reading Chapter 9 of Garcia’s Book (ATM) Home work #2 List the Features of ATM Read Amit Singhal, Raj Jain, "Terabit switching: a survey of techniques and current products," Computer Communications, Vol. 25, No. 6, April 1, 2002, pp. 547-556

9. Grading Policy Homework assignment and reports 50% Class participation 25% Exam 25%