1. VP Technology Strategy Marconi Communications
MPLS in the broadband IP Network
Good morning ladies and gentlemen, it is a priviledge to be able to address your conference.
My name is David Drury and I am Vice President of Technology Strategy for Marconi PLC, a major supplier of communications equipment, but I am also President and Chairman of the MPLS Forum and it is in that role that I give this presentation
My topic is MPLS in the Broadband IP network
David Drury
President & Chairman
VP Technology Strategy
Marconi Communications

2. MPLS is the enabling technology for the New Broadband (IP) Public Network
In the move from the best effort IP networks of today, to the multi-service IP networks that will be the basis of the New Public Network tomorrow, MPLS is a critical enabling technology, adding many necessary characteristics
A) Scaling
B) Traffic engineering
C) Cos and QoS support
D) Isolation of IP networks with non unique IP addressing schemes
MPLS truly is the enabling technology for the New Broadband (IP centric) public network

3. Status today Traffic growth is on IP best effort networks
Revenue is still predominately voice and other deterministic services
Building multiple overlay networks is not cost effective
But how can IP networks support true multi-service capability and scale to meet the needs of the broadband future.
To find out why this is so consider the current situation
Traffic growth of IP best effort networks is explosive, the internet traffic is growing at something like 400% per anum and shows no sign of stopping
BUT and it’s a big but, most Operators revenue is still predominantly voice and other deterministic services such as leased lines, frame relay or ATM services
In the past each new service has been built on its own overlay network, where at best some common transmission layer was used, but increasingly that is not seen as a economic way forward that can respond to the demands of the new network, speed of provisioning and rapid scalability.
But current router based IP networks do not support the conventional traffic – so how can we build an IP network that not only comes with the growth of IP traffic but that also supports the existing revenue services too

4. Topics covered What is Multi-protocol label Switching
How does it fit into IP network development plans – MPLS Applications
The role of the MPLS Forum
The subjects I will cover to day are just three
A very brief introduction to the essential elements of Multiprotocol Label switching
Where MPLS fits into IP networks of the future – in other words the applications of MPLS
And finally I will cover the role of the MPLS Forum in assisting the deployment of MPLS

5. What is Multi-protocol Label Switching ?

6. MPLS Technology
Routers or switches that handle MPLS and IP are known as Label Switch Routers (LSR’s)
LSR’s at the edge of MPLS networks are sometimes referred to as Label Edge Routers (LER’s)
Ingress LER’s are responsible for classifying unlabelled IP packets and appending the appropriate label.
Egress LER’s are responsible for removing the label and forwarding the unlabelled IP packet towards its destination.
All IP packets that follow the same path through the MPLS network and receive the same treatment at each node are known as a Forwarding Equivalence Class (FEC).
Let me start with some basic terminology – Routers or Switches that handle MPLS and IP are known as Label switch routers – pretty obvious really !! Or LSR’s just to make sure the uninitiated don’t understand
LSR’s can be inside an MPLS cloud but the LSR’s at the edge of the network, ie where unlabeled IP packets get classified and then have the appropriate label attached are sometimes refered to as Label Edge Routers or LER’s

7. MPLS Technology There are three key elements of MPLS
The MPLS header stack
Which contain the MPLS label on which Label Switch Routers will forward the packet. Headers can be stacked.
The enhanced IP routing protocols
Which distribute topology and constraint based data
The label distribution protocols
The standardized connection establishment protocols through which LSR’s set up a complete path from ingress LSR to egress LSR. This path is known as a Label Switched Path or LSP.
MPLS adds a connection oriented paradigm into IP networks

8. MPLS Shim Header Structure
...
Layer 2 Header
IP Packet
Label: 20-bit value, (0-16 reserved)
Exp.: 3-bits Experimental ( ToS)
S: 1-bit Bottom of stack
TTL: 8-bits Time To Live
Label
Exp. S
TTL
4 Octets
Label Switching
Look up inbound label + port (+Exp)
to determine
outbound label + port + treatment
Header operations
Swap (label)
Push (a new header)
Pop (a header from stack)
This is the basic MPLS packet format.
The 32-bit MPLS field is known as a "shim header". This comes from an engineering term - a "shim" is a thin strip of material used to makes parts fit correctly. When you fold up a beer mat to stop a bar table from wobbling you are using a shim!
The first 20 bits of the field actually represent the label. The next three bits are currently "experimental" and must be set to zero. The next bit indicates if this label is part of a stack of labels. If the S-bit is zero, then this is the only label.
The Time To Live (TTL) field is as per a normal IP packet, and is there for the same purpose (loop detection).
MPLS encapsulations are also defined for ATM and Frame relay.

9. Establishing the label bindings
Each switch needs a table that contains the actions it is to perform when a given label arrives.
The downstream end of a link needs to know what label values will be sent.
This can be done by management action – directly equivalent to PVC’s in ATM.
But this does not scale well.
And there is no interoperability between management systems – so multi-operator connections are difficult if not impossible.
Hence trend to protocol driven service establishment and the reason for IP’s success.
So we need to automate the LSP establishment process.

10. MPLS Routing protocols
Start with existing IGP’s
OSPF
IS-IS
BGP-4
Enhance to carry constraint data
OSPF-TE
IS-IS –TE
Distribute topology information only
The first part of automating the establishment of LSP’s is to have a routing protocol distribute topology information, and the current IGP’s OSPF, IS-IS and RIP do that.
However these protocols simply enable an individual router to decide the port that is on the shortest path to the destination IP address
Traffic engineering is seen as an essential element of running an effective large best effort IP network, and to address the needs of traffic engineering the routing protocols must be enhanced to provide much more data. For example the capacity of all the links between the ingress and egress node, the current utilization of each link, the delay across the link, whether the whole span has protection switching or not and so on. We may also want to set by management some link characteristics ie resource classes that allow the ingress LSR to include or exclude certain resources
Constraint based routing is the key to Traffic engineering
Constraint data
Link capacity,Link utilization
Resource class
Priority
Pre-emption etc
Constraint based routing is the key to Traffic Engineering

11. Label Distribution Protocols
Hop by Hop routing
Ensures routers agree on bindings between FEC’s and the labels.
Label paths follow same route as conventional routed path
LDP
CR-LDP
RSVP-TE
Explicit constraint based routing
Route determined by ingress LSR based on overall view of topology, and constraints
Traffic engineering
CoS and (QoS)
fast (50ms) rerouting

12. MPLS Partitions Routing and Forwarding
Based on:
Classful Addr. Prefix?
Classless Addr. Prefix?
Multicast Addr.?
Port No.?
ToS Field?
Routing
OSPF, IS-IS, BGP, RIP
Forwarding Table
Forwarding
Based on:
Exact Match on Fixed Length Label
MPLS
By separating Routing from forwarding MPLS introduces more flexibility to develop new routing solutions without impacting the data plane hardware of label switch routers
Single forwarding paradigm – multiple routing paradigms
The edge LSR is able to use a wide variety of input in determining the FEC, and not just the destination IP address
Flexibility in forming FEC’s

13. IETF Document status
With rfc editor
Multiprotocol Label Switching Architecture
MPLS Label Stack Encoding
Awaiting final IESG approval
Use of Label Switching on Frame Relay
VCID Notification over ATM link for LDP
LDP State Machine
MPLS using LDP and ATM VC Switching
LDP Applicability
Applicability Statement for Extensions to RSVP for LSP-Tunnels
Awaiting IESG Last Call
Carrying Label Information in BGP-4
ICMP Extensions for MultiProtocol Label Switching
IESG comment resolution
A Framework for MPLS
Extensions to RSVP for LSP Tunnels
Constraint-Based LSP Setup using LDP
Applicability Statement for CR-LDP
WG Last Call
LDP Specification
MPLS Support of Differentiated Services
WG Last Call comment resolution
Definitions of Managed Objects for the Multiprotocol Label Switching, Label Distribution Protocol (LDP)
MPLS Label Switch Router Management Information Base Using SMIv2
There are currently 81 Internet Drafts that reference MPLS

14. How does it fit into IP network development plans – MPLS Applications

15. Applications of MPLS Traffic Engineering
Adding Class of Service (CoS) and Quality of Service (QoS)
Network scalability
Supporting IP VPN’s

16. Traffic Engineering Current IGP’s lead to Hyper-Aggregation
TRAFFIC FOR D
SHORTEST PATH ROUTED D S
MASSIVE
CONGESTION
CONGESTION

17. Traffic Engineering Current IGP’s lead to Hyper-Aggregation
TRAFFIC FOR D
SHORTEST PATH ROUTED
9 UNDER ULTILIZED]
4 OVERUTILIZED ]
LINKS D S
MASSIVE
CONGESTION
CONGESTION

18. Traffic Engineering IS the Answer
Objectives
Map actual traffic efficiently to available resources
Controlled use of resources
Redistribute traffic rapidly and effectively in response to changes in network topology - particularly as a consequence of line or equipment failure
Note this complements Network Engineering
Putting the network where the traffic is

19. Traffic engineering distributes traffic
Traffic distributed over
Network resources by
MPLS traffic engineering
- Congestion eliminated D S

20. Benefit of MPLS traffic engineering
Traffic engineering in large IP networks currently uses ATM.
The router network is ATM unaware and hence there are two control planes.
The router control plane has a large number of adjacencies which limits scalability.
MPLS is IP aware and introduces a single IP control plane that matches the physical topology and hence scales better and is simpler.
This is being extended into MPS (MPLambdaS) to extend Traffic Engineering to the emerging Optical networking plane

21. Adding CoS and QoS
Explicit path set up can also associate specific resource requests with an FEC
Class of service
Establish relative priority of one FEC over another – no absolute guarantees
Quality of service
Specific guarantees on
Bandwidth
Delay
Burst size etc
Primary objective is for MPLS to support the Diff-Serv QoS model (EF, AF1-12,etc)
CoS and QoS require explicit support in the data plane of the LSR’s

22. Benefits of MPLS QoS
The ultimate benefit is a unified or converged network supporting all classes of service
The IP Qos model for the support of real time services such as voice is at an early stage.
Most multi-service networks are moving to a “Ships-in-the-night” paradigm
This continues to support ATM services with ATM protocols
And at the same time on the same platforms supports and MPLS control plane of IP services

23. Hierarchy via Label stack = Network scalability
Layer 2 Header
Label 3
Label 2
Label 1
IP Packet
Within each domain the IGP simply needs to allow the Boarder (ingress) routers to determine the appropriate egress boarder router
Reducing drastically size of routing table in transit routers
MPLS Domain 1
MPLS Domain 2
Let's look a bit more closely at those labels.
MPLS labels can be stacked one on top of another.
The way that this stacking is build up and stripped off can lead to nested MPLs domains, as I show above...
MPLS Domain 3

24. Benefit of MPLS in scaling
MPLS labels introduce hierarchy
Transit routers no longer need to handle complete routing tables
New layers of the hierarchy can be introduced as needed for scaling.

25. Support of IP VPN’s A Virtual Private Network
An IP network delivering private network services over a public infrastructure
Supports global and non unique private address space
Supports CoS and QoS
Use of labels isolates IP addresses within public network from customer IP addresses
Creates a highly scalable VPN
Not currently standardized by IETF

26. Benefit of MPLS IP VPN’s
Provides a mechanism to scale both the number of VPN’s and the number of members per VPN to very large numbers.
Allows VPN’s to have non-unique IP addressing
Provides for a great deal of flexibility in defining the VPN service (from the mapping to FEC’s)
Enables meaningful CoS and QoS Service Level Agreements (SLA’s) to be associated with a VPN

27. MPLS Status
MPLS is a critical additional capability for IP networks. It solves problems for which no other solutions are known.
It is difficult to anticipate the longer term future and what applications may be supported because of the innovations MPLS enables.
MPLS introduces a significant architectural change in IP networks.
It is the future of the converged IP network

28. The role of the MPLS Forum

29. Our goal
The MPLS Forum is an international industry forum accelerating the adoption of Multi Protocol Label Switching (MPLS) and its associated technologies.
These Technologies are critical to the creation of the New Public Network
The New Public Network
$120B/year IP VPN new revenue by 2010
$380B equipment sales over next seven years

30. Membership Growth 21 Principal Members (7 Operators/Service providers)
30 Small Principal Members
Not for profit

31. The role of the Forum Interoperability Applications Education
Defining capability sets and working with Interoperability labs
Applications
Applications are typically not covered by IETF
Education
Producing an 8 hour MPLS tutorial
Will produce other MPLS training material
Web site (

32. The four point plan
Focus on speeding successful deployment of MPLS technology
MPLS interoperability initiatives
SLA definitions and validation
Education and tutorial material creation

33. The organization of the Forum
Board of Directors
The Market Awareness and Education Committee
The Technical Committee
Work items driven by member contributions
Focused on requirements not covered in any other standards body
Liaison with IETF, ITU, ATMF, etc

34. Summary of last TC meeting
Swisscom, France Telecom, Broadband Office presented their requirements on MPLS
Results of interoperability testing at UNH and demo at Networks+Interop
Protection switching and recovery with MPLS
Discussion on first TC contribution
Voice over MPLS
Accepted by the meeting as an on-going work item
(Explicitly excluded in Adelaide from the IETF MPLS WG charter)

35. Concluding remarks MPLS is a very important extension to IP networks.
It is a key element of moving from best effort IP networks today to true multi-service new public networks of tomorrow
The base standards are technically stable and initial implementations are underway in the core
Interoperability and completion of other drafts is essential before MPLS can extend to the edge.
The MPLS Forum is speeding up the deployment process and opening new application areas.

36. For more information – MPLS Forum
39355 California Street, Suite 307
Fremont, CA 94538
Fax:
WWW:
Alexa Morris Executive Director
Phone:
Or to me - David Drury

37. Thank you