Old Dog Consulting A Unified Control Plane Dream or Pipedream? Adrian Farrel Old Dog Consulting IETF Routing Area Director

Old Dog Consulting

A Unified Control PlaneDream or Pipedream?

Adrian Farrel

Old Dog Consulting

IETF Routing Area Director

Page 2© Copyright Old Dog Consulting 2010

Agenda• History

• Where does it all come from?

• Objectives and Dreams• Development

• Extensions and Divergence

• Success Stories• Disappointments• Why are we here?

• Why has GMPLS not taken over the world?• Why are we here in Tokyo, now?

• Where are we going?


MPLS is Established

• MPLS is 13 years old• I have the T-shirt from MPLS2007

• All (nearly all?) major service providers have MPLS in their core networks

• The majority is LDP or L3VPN

• MPLS-TE has limited, but successful deployment


WDM and Automation• As MPLS-TE was being developed

• Technical advances in WDM• Deployment and research of WDM systems• Management-based solutions becoming

complex

• Proposals extend MPLS-TE to provide an automated control plane for WDM systems• Multiprotocol Lambda Switching (MPλS)• draft-awduche-mpls-te-optical-00.txt

• April 2000• Awduche, Rekhter, Drake, Coltun


Generalisation• If you can do it for packets and lambda

• Why not do it for all connection-oriented networks?• Isn’t all circuit switching the same?

• CO-PS• MPLS• ATM• Frame Relay• Ethernet

• CO-CS• Fibre• Lambda• TDM

• draft-ietf-mpls-generalized-signaling-00.txt• October 2000• Multiple ideas, many authors


Protocol Development• MPLS-TE protocols had been

developed already• Routing• Signalling

• Generalisation of these protocols to GMPLS• Intent that GMPLS included all existing

traffic engineered MPLS

• New protocols only where new needs• LMP• PCEP


Two Protocols for Every Use• OSPF and IS-IS• RSVP-TE and CR-LDP• LMP and Nortel’s own offering• Lessons from history

• We do not need multiple solutions for the same problem• Development cost is more than doubled

• Who pays?• Interoperability is compromised

• Providers are “locked in”• Deployment is complicated

• Additional or more expensive operations teams• Company mergers, etc. become a nightmare

• “Wrong” decisions are made• Consider regional standards that pick the “wrong” protocol

Two roads diverged in a yellow wood,And sorry I could not travel bothAnd be one traveller…

Robert Frost (The Road Not Taken – 1915)

• The IETF made decisions• Only LMP was taken into the CCAMP working group• RFC 3468 stopped work on CR-LDP• OSPF and IS-IS too well deployed to make a choice


And Did It Work…?

• Lots and lots of implementations• This was around 2000• Everyone was building an optical switch• Most implementations were for WDM

• Significant research• Theoretical work to prove utility of control plane• Experimental equipment and networks

• A lot of successful control plane interop testing• GMPLS-enable equipments shipped


Where are the Deployments?

• GMPLS deployments do exist• WDM deployments tend to be small

• Metro add/drop• GMPLS is a management tool• Reduces the complexity of provisioning

• Single-touch connection set-up• Network status information gathering• Intelligence remains in the NMS (not in the network)

• Some significant long-haul networks• Networks tend to be very stable• GMPLS is just a provisioning tool

• SDH networks• Many networks deployed• Some are quite large

• GMPLS has not taken over the world


And What Didn’t Work?

• Many issues conspired to slow GMPLS• The bubble burst• TDM deployments too established

• Retro-fitting GMPLS not attractive

• No pressure to migration packet networks from MPLS-TE to GMPLS

• PBB-TE didn’t take off

• But GMPLS did fulfil its technical promise


Why Isn’t GMPLS Widely Deployed?

• The equipment was available• The providers were looking at deployment• But?• There are a number of roadblocks

• Data plane interoperability• Equipment cost• Control channel interoperability• Control plane interoperability• Operational hurdles• Network complexity


Roadblocks 1: Data Plane Interop

• No point in a unified control plane if the data plane doesn’t interwork

• WDM systems• Different choice of lambdas• Different power levels• Complex optical impairments• Different encodings

• TDM• SONET/SDH• Different options and features

• 2.5G, 10G, 40G encoding and modulation• Why?

• Uncoordinated development under time pressure• Regional preferences• It is not a benefit to the incumbent vendors to interoperate


Roadblocks 2: Equipment Cost

• GMPLS is most effective in dynamic networks• Dynamic networks need flexible,

reconfigurable equipment• Flexible equipment has been expensive

• For example, in a WDM network• Best flexibility is achieved using OEO• OEO has been the most expensive equipment

• For example, control plane handling• Previous transport equipment

• Only needed lightweight CPU

• Only needed low bandwidth management channels

• Introduction of a control plane added cost


Roadblocks 3: Control Channel Interop

• Mainly an issue in WDM systems• How to adjacent WDM nodes communicate in

the management and control planes?• In the lab we use 10/100 Ethernet

• You can’t deploy that• You could connect to an IP cloud

• Most WDM equipment has an Optical Supervisory Channel (OSC)• There are no standards for the OSC

• It is not a benefit to the incumbent vendors to interoperate


Roadblocks 4: Control Plane Interop

• The point of standards is to achieve interoperability

• Multiple conflicting standards do not help• Why does “standards shopping” happen?

• Vendors want to add value• Competitive edge is important• Vendor-specific extensions tend to break

interoperability• They don’t need to• Why should an incumbent vendor enable interop?


Roadblocks 5: Operational Hurdles

• Transport network operation is well established

• Transport operators are conservative• Risk-averse• Demand stability

• Huge investments already made• Extensive management systems• Education and training

• A control plane is a big hurdle


Roadblocks 6: Network Complexity

• GMPLS is intended to simplify the network• Why do people think it makes it more complex?

• A very rich function set• Core GMPLS includes many features that are “advanced

functions” in traditional networks

• A very advanced toolkit• We are engineers – we like to build things• It is easy to apply GMPLS to some very complex problems

• Vendors need to understand and sell simplicity• Service Providers have to learn to prioritise their

requirements


So, Why Are We Here?


The Prospects Are Still Good!

• Plenty of other reasons to be here• Interworking between network “islands”• Continuation of the Ethernet project• Optical Transport Networks (OTN)• Advances in WDM• Green Networking• Integrated networking (IP-over-Optical)• MPLS Transport Profile


Network Interworking• When there are vendor islands

• Still want end-to-end automation• Need “service interface” (UNI)• Need glue between networks (E-NNI)

• ITU-T ASON architecture makes these clear• MEF calls specifically for a UNI• Huge benefit in a standard protocol solution at these

interfaces• ITU-T solutions (PNNI, CR-LDP, RSVP-TE)• OIF solutions (RSVP-TE)• GMPLS

• We need a solution• We don’t need five solutions!• If GMPLS is also used at (some) I-NNI then choose GMPLS• All the RFCs exist for immediate deployment for ASON• I-Ds to support MEF UNI are about to become RFCs


Ethernet TE is Not Dead• The scope of PBB-TE is not as large as

predicted• Campus-style deployments are still likely• Core backbone usage to link routers• Not used to build a fully-meshed core

• Network diameter and complexity is not huge• Somewhat complicated resource sharing

required• Planned reduction in forwarding table size• GMPLS offers automated and simplified

management• I-D is about to become and RFC


OTN• G.709 is not new

• Sub-lambda technology• Recent major advances in technology

• New revision of G.709 (version 3)• Support for 1.25Gbps and 2.5Gbps• ODU-flex

• More flexible and attractive• Considerably interest in implementation and deployment

• RFC 4328• Support for G.709 version 1

• New work in CCAMP• Re-assess label format• Support all resizing and advanced features


WDM Resurgence

• Continued increase in bandwidth demand• Introduction of lower-priced components

• PICs make OEO more affordable

• Introduction of smaller all-optical cross-connects• 2x2 and 4x4 matrices• Makes phased deployment of PXCs realistic

• ROADMs• GMPLS building blocks all in place• Next steps are impairment-aware routing

• First stages almost complete in CCAMP and PCE


Green Networking

• A very real demand to reduce energy use

• Requirements are not limited to equipment

• It is important to route traffic to• Use most power-efficient path• Make best use of existing paths

• Increases the pressure for advanced TE• Needs to be dynamic• Needs sophisticated path computations• Most effective when integrated across layers


Integrated IP-Optical• This is the sixth year of iPOP

• Are we wasting our time?• Maybe operators really don’t want this

• Too dynamic• Too hard to operate• Too complex to deploy

• Many attractions• Flexible equipment deployment• Flexible re-grooming• consolidated operations

• Facilitated by many innovations• High capacity, tuneable, interfaces on routers (lambda,

OTN…)• OTN flexibility• Plug-and-play integrated devices• Advanced planning software and PCE• Integrated GMPLS control plane


MPLS-TP• Transport-grade MPLS

• OAM• Bidirectional• Protection and restoration• Optional, high-grade, TE control plane

• Work in the IETF with ITU-T cooperation• Control plane will use GMPLS• Equipment interoperability is a MUST• Questions:

• Will a control plane be used, or just management?• Will GMPLS be adopted in MPLS-TE networks?


Where Next?• A rocky road, but…

• We have a very rich control plane toolset

• The future is in your hands• We have all of the building blocks

• New work is either very specific or very minor• We have the experimental evidence• The vendors have a marketing story• The providers see the benefits

• Get on with it!• Issue the RFQs• Build and ship the products• Deploy the networks


Questions

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Old Dog Consulting A Unified Control Plane Dream or Pipedream? Adrian Farrel Old Dog Consulting IETF Routing Area Director