This tutorial session will provide an overview of the LDP protocol followed by a look at LDP fault tolerance mechanisms. We will then describe the major LDP applications existing today and deployment considerations. A more detailed description of some of the topics that will be covered follows :

LDP Overview :
    - Transport over TCP
    - Session initialization state machine
    - Link level and targeted adjacencies
    - The concept of a label space
    - Label destribution procedures with emphasis on downstream unsolicited mode
    - Messages and TLV formats

LDP Fault Tolerance :
    - What is LDP fault tolerance or graceful restart ?
    - Why is LDP graceful restart important ?
    - IETF update
    - Description of the "learning from network" approach
        What are the assumptions on state stored across restart ?
        LDP protocol extensions for graceful restart
        Procedures for the restarting LSR and its neighbors

LDP Applications :
    - A migration step from IP to MPLS
    - Building BGP/MPLS VPNs using LDP
        LDP tunnels and BGP next hop
        Label Stacking
        Scalability
    - Signaling mechanism for Layer 2 VPNs
        LDP/Martini extensions for layer 2 VPNs
        Label stacking
        Tunneling technology in the core
    - Deployment Considerations
        Scalability
        Isolating faults in the network
        Debuggability

Enke Chen is currently a principal engineer working on IP routing software development at Redback Networks. Previously he was a senior software engineer working on BGP at Cisco. He also worked on the design and engineering of the Internet MCI backbone network at MCI, and the NSFNET backbone at Merit. Enke Chen holds a Ph.D. in Electrical Engineering: Systems from University of Michigan, Ann Arbor.

Rahul Aggarwal is a Software Engineer in the SmartEdge IP routing group at Redback Networks, which he joined in March 2000. He is one of the leading architects and developers of the MPLS implementation on the SmartEdge 800 Router. He is currently contributing to the design and development of MPLS Traffic Engineering, Layer 3 and Layer 2 VPNs.

Prior to joining Redback Networks, he was at Fore Systems between 1998 and 2000, where he worked on the development of OSPF, MPLS and Traffic Engineering. He received a B.E. in Electronics and Communication from Indian Institute of Technology, Roorkee in 1996. He received his M.S. in Computer Science from University of Minnesota in 1998. His Graduate Research was focussed on QoS and stored video delivery across resource constrained networks.

His professional interests include routing and signaling development, IP and MPLS system and forwarding design, packet classification, VPNs, QoS and Traffic Engineering.