Transcript MPSL and

MPLS and Traffic
Engineering
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
Outline
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Traffic engineering in IP Networks
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Multiprotocol Label Switching
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MPLS Applications
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Traffic Engineering with MPLS
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
Traffic Engineering in IP Networks
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Coping with Internet growth
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Network architecture
Capacity expansion
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Increase the number of circuits
Increase the bandwidth of existing circuits
Increase the capacity of the core routers
Add more core routers
Traffic engineering
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Wait until QoS becomes ubiquitous and leverage it for admission
control
Better utilize all available bandwidth in the core
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
BGP Topology
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
Internet Traffic Engineering
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Motivation
 Architecture paradigms and simple capacity expansion are necessary, but
not sufficient, to deliver high quality Internet service under all
circumstances.
Definition
 The aspect of Internet network engineering that addresses the issue of
performance optimization of operational networks.
 Application of technology and scientific principles to the
 measurement
 Modeling
 Characterization
 Control of Internet traffic
 Application of knowledge and techniques to achieve specific performance
objectives.
Goal and purpose
 Reliable and expeditious movement of traffic through the network
 Efficient utilization of network resources
 Planning of network capacity
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
Conventional IP Technologies
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Advantages
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Highly distributed and scalable
Disadvantages
Doesn’t consider the characteristics of offered traffic and network
capacity constrains when making routing decisions
 Inadequacy of measurement functions
 The limitations of intra-domain routing control functions
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Consequences
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Poor network resources allocation
 Some subnet resources become congested
 Some subnet resources along alternate paths remain underutilized
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
MPLS
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Idea: leverage layer 3 interior routing protocols (OSPF and IS-IS) to calculate
shortest paths to all possible destinations, but then assign a sequence of
labels/tags along each path.
Label Switched Path (LSP) and LSP tunnel
CMPT771 - 2008 Spring
MPLS – Cont’
Liang Zhou Jiang (Jeff)
MPLS – Cont’
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CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
Traffic parameters
 Adaptivity attributes
 Priority attributes
 Preemption attributes
 Resilience attributes
 Resource class affinity attributes
 Policing attributes
Components of the MPLS Traffic Engineering Model
 Path management
 Path selection
 Path placement
 Path maintenance
 Traffic assignment
 Partitioning function – partition ingress traffic according to some principle of
division
 Apportionment function – allots the partitioned traffic to established LSP tunnels
according to some principle of allocation
 Network state information dissemination
 Extending conventional IGP to propagate additional information: Maximum link
bandwidth, maximum allocation multilplier default traffic engineering metric,
reserved bandwidth per priority class, and resource class attributes
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Network management
MPLS Applications
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Short cut routing
 BGP
Next Hop
 A MPLS Short Cut to BGP Next Hop
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Tunnel Restoration
 Planned Head
 Fast Reroute
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End Reroute Capability
Integrating MPLS and QoS
 Integrated Services
 Differentiated Services
 IntServ Meets DiffServ and
MPLS at the Internet Core
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
MPLS – Cont’
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
MPLS – Cont’
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
MPLS – Cont’
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L-LSP’s for Mapping DiffServ to MPLS
E-LSP’s for Mapping DiffServ to MPLS
Major components of Traffic Engineering with MPLS
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User interface for articulating traffic engineering policy in terms of
constraints to conventional SPF
 IGP component which is composed of traffic engineering extensions to
IS-IS and OSPF
 Signaling component which is based on traffic engineering extensions to
RSVP or CR-LDP
 Traffic Engineering Policy
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
Traffic Engineering with MPLS
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Administratively Specified Explicit Path Selection
Resource Class Affinity
Label Switched Path Adaptivity
Label Switched Path Bandwidth Reservation Priority
Label Switched Path Preemption
Load Distribution Across Parallel Label Switched Paths
Label Switched Path Resilience
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
Conclusion
The resiliency and adaptability of the Internet is unparalleled in the history of
communications. The Internet, with its growing suite of open and standardized
protocols, is the clear winner in the inevitable convergence of private line,
voice, video, and outsourced data services. MPLS is only the latest entrant in
this remarkable evolution. MPLS when combined with traffic engineering
deliver a formable tool for meeting the rigid requirements of differentiated
services by leveraging the strengths of IP routing, the proven scalability of
terabit routers, and the mechanisms for end to end QoS.
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)
References
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"A Framework for MPLS", Ross Callon, George Swallow, N. Feldman, A.
Viswanathan, P. Doolan, A. Fredette, 09/22/1999. (180569 bytes)
"Multiprotocol Label Switching Architecture", Ross Callon, A. Viswanathan, E.
Rosen, 08/27/1999. (145481 bytes)
"MPLS Label Stack Encoding", Dino Farinacci, Tony Li, A. Conta, Y Rekhter, Dan
Tappan, E. Rosen, G. Fedorkow, 09/13/1999. (46971 bytes)
"Extensions to RSVP for LSP Tunnels", Der-Hwa Gan, Tony Li, George Swallow,
Lou Berger, Vijay Srinivasan, Daniel Awduche, 09/29/1999. (105164 bytes)
"MPLS Support of Differentiated Services", Bruce Davie, Pasi Vaananen, Liwen Wu,
Francois Le Faucheur, Pierrick Cheval, Ram Krishnan, Shahram Davari, 10/11/1999.
"Applicability Statement for Extensions to RSVP for LSP-Tunnels", Alan Hannan,
Daniel Awduche, X Xiao, 10/05/1999. (17395 bytes)
“MPLS Optimized Multipath (MPLS--OMP)”, Curtis Villamizar, February 25, 1999
"OSPF Optimized Multipath (OSPF-OMP)", Curtis Villamizar, 02/25/1999. (90622
bytes)
“IS-IS Extensions for Traffic Engineering”, Henk Smit, Tony Li, May 1999
“OSPF Extensions for Traffic Engineering” Derek M. Yeung, February 1999
“RSVP Label Allocation for Backup Tunnels”, Robert Goguen, George Swallow,
October 1999
CMPT771 - 2008 Spring
Liang Zhou Jiang (Jeff)