The Impact of SDN On MPLS Networks Adrian Farrel Juniper Networks [email protected]

www.mpls2012.com

Agenda

• • • • • • •

Some Definitions Needed (SDN) Why consider SDN?

SDN as a toolkit Fine-grain programming An interface to routing and policy Enabling services A programmable MPLS network

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What do we mean by SDN?

• Software • • It’s all software!

We are looking for automation • Tools or applications • Driven or Defined • Does it matter?

• Networks • • • Micro-management of forwarding decisions Control of end-to-end paths Whole-sale operation of network • Is it all about the buzz?

• S

hiny-thing

D

esparately

N

eeded

• $

ome

D

ollars

N

ow 3

What will we do with SDN?

• Make our networks better • Provide cool services at lower prices • Reduce OPEX and simplify network operations • Enable better monitoring and diagnostics • Make better use of deployed resources • Converged services are the future • Converged infrastructure is the future 4

The SDN Toolbox

• To a network, all configuration tools look like hammers • One size does not fit all • SDN is about engineering the routers to allow better tools to be designed and applied 5

MPLS Data Plane Programmability

• Label stacking, popping, and swapping • • MPLS as a cross-connect technology (NHFLE) Prefix-to-label mapping (LFIB) Prefix LFIB Out i/f, label NHFLE In i/f, label Out i/f, label NHFLE In i/f, label Pop IP Packet MPLS Packet MPLS Packet • Integration with underlying data plane • Encapsulation rules • Data link addresses 6 IP Packet

Applications and Protocols for MPLS Data Plane Programmability

• An application is software that runs remotely • That demands a protocol and a data encoding • Element Management • • • IETF : SNMP/MIBs, Netconf/YANG Proprietary : CLI, GUI, XML Legacy : TL1 … • Network Management • Coordinated connection set-up is just coordinated element management • Control plane / data plane separation • • • Use an existing configuration protocol IETF : GSMP (RFC 3292), ForCES (RFC 5810) ONF : OpenFlow 7

Control Plane / Data Plane Separation

• Support legacy / cheap devices • Experiment with new routing protocols • Integrate dynamic routing with static control • Avoid “complexities” of routing protocols Control plane SDN Programming Language Data plane 8

Functional Control at a Higher Level

• Operators want to build and deploy services • • • • • • • “Make a pseudowire for me” “Optimize my traffic loading” “Provision a layer 3 VPN” “Show me how my network is being used” “Configure my data center” “Manage security and policy” “Provide service callendaring” • Needs a higher-level interaction with the network • Demands more sophisticated control of routers • Must integrate with standard routing features 9

Leveraging Existing Tools

• New services and features for rapid deployment • There are plenty of existing tools • Leverage implemented and deployed protocols • We can put them together to enable high function SDN in MPLS networks • May need some extensions • Avoid long development cycles 10

BGP-LS to Extract Topology Information

• Information about the network • • • • • Nodes and links Link state Up-to-date TE capabilities Delay and other quality information Status of existing LSPs / tunnels • Used for network monitoring, analysis, and planning • Critical input to path computation (e.g., via PCE) • Fundamental component unspecified in the PCE architecture • BGP-LS is a set of simple extensions to BGP • Client is any node listening to the IGP • For example an ASBR or a Route Reflector • • Server can not be a very light-weight BGP implementation Reduces dependency on IGP sniffing 11

Stateful PCE for Control of Services

• Early work on PCE was stateless • PCE knows state of network • • PCE does not recall anything about previous computations PCE does not know about existing provisioned services • Except as described on new computation requests • Stateful PCE was always in the architecture • Retain information about provisioned LSPs • New extensions to PCEP • Allow explicit activation of LSPs from the PCE • Receive information from network about LSPs • Provides key components for bandwidth callendaring 12

Integrating the Components

• • • • •

IGP enhanced for TE and link quality BGP-LS reports to PCE PCE requests LSPs Normal LSP signaling LSP status reports

PCE 13

Making New Tools

• Can’t do

everything

with what have already • Interface to the Routing System (IRS) • A programmatic interface to routers

Application Application Server IRS Client Application IRS Client IRS Protocol & Data Encoding Router OAM, Events and Measurement IRS Agent Topology DB Routing and Signaling Protocols RIBs and RIB Manager Policy DB Data Plane FIB 14

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Enabling Services

• Service enablement and turn-up is complex • Existing tools help with planning • Commissioning through scripts or work-plans • SDN can be a set of tools to enable services • L3VPN delivery • • • Data center interconnect Bandwidth callendaring Mult-layer connectivity and virtual links 15

Service Example : Multi-layer

• SDN can coordinate multiple network layers • May both be MPLS networks • Involves many SDN components Traffic demand Service request IRS PCE PCEP TEDB IRS RSVP-TE Policy IRS VNTM PCEP IRS BGP-LS GMPLS PCE TEDB IGP-TE 16 IGP-TE Virtual Link OpenFlow & IRS

Service Example : L3VPN with Callendaring

• • • • Which PEs to use?

How to connect PEs?

• • What load? When?

What redundancy? QoS? Security?

How to connect to the Internet?

Planned support for high bandwidth services

DB Replication Content Streaming Data Transfer

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Putting the Tools into the Box

• SDN will possibly remain buzz and hype • Or maybe it will evolve into bickering between proponents of different solutions • Or it could become a comprehensive set of tools • Configuration tools • • • RIB and policy control Topology and LSP management Service enablement • Potential to enable a rich set of functions in future MPLS networks 18

SDN Pandora’s Toolbox?

A mess of overlapping tools and protocols with too many features and functions?

Or a cornucopia of riches?

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Questions?

[email protected]

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