Interface to the Routing System Adrian Farrel adrian@olddog.co.uk afarrel@juniper.net

Agenda What is the Routing System? What do we want to do with the Routing System? What tools already exist? An architecture for IRS Requirements for IRS IRS Work to be done Integrating the toolkit

The Routing System The forwarding plane is just part of a router We are interested in larger granularity impact Router Topology DB OAM, Events Measurement Config Config DB RIB Routing and Signalling RIB Manager Policy DB Data Plane OpenFlow FIB 3

Advanced SDN Use Cases Programming the Routing Information Base For example, adding static routes Setting routing policy Control how the FIB is built Other router policies Modify BGP import/export policies Topology extraction Pull routing information (including SRLGs) from network Topology management Create virtual links by making connections in lower layers Service management Request LSPs, connections, pseudowires Bandwidth scheduling “Set up a VPN”

Existing SDN Tools - OpenFlow Useful, programmatic remote API Initially targeted at data / forwarding plane Separation of control plane from data plane RAPI nature introduces extensibility issues New revisions not backward compatible Hard to add new data models Current version has some concerns Synchronous completion is assumed No support for bidirectional flow Security model is not complete Use needs coordination A routing protocol An orchestrator

Existing Tools - ForCES IETF protocol and encoding language An open standard Separation of control and forwarding planes Originally developed to support COTS Standard, but in-box protocol Use rapidly extended to out-of-box Has been used to model OpenFlow Provides the same level of function Use needs coordination A routing protocol An orchestrator

Existing Tools - Config All routers have configuration interfaces Command Line Interface Non-standard Varies from one product release to the next Easy to script Hard to parse output ("screen scraping") All config approaches tend to be batched Enter many config commands Verify the config Commit So config is slow and complicated

Existing Tools - Netconf / YANG IETF standardised protocol and encoding language Netconf Next generation configuration protocol Lessons learnt from SNMP Reduced "chattines" of protocol Multiple objects set at once Security is far simpler YANG XML-like encoding language Easy to define new data models Not yet widely adopted Usage currently has many of the disadvantages of config

Existing Tools - PCE Initially conceived as a path computation server Solving the problem of inter-AS MPLS-TE Stateless computation Uses Traffic Engineering Database Extended for stateful computation Recalls information about previous computations Learns state of provisioning from network New extensions for "Active PCE" PCE can issue provisioning commands Enables new services Topology creation Scheduled services Dynamic re-optimisation and grooming

Existing Tools - BGP-LS How does a PCE obtain the TED? Unspecified in the architecture Early implementations participate in IGP Updates may be too frequent Implementations must support IS-IS and OSPF Most TE networks have a BGP-capable router BGP nodes are designed to process routing policies BGP-LS is set of simple extensions to advertise topology info Speaker Possibly a Route Reflector Uses policy to determine what to advertise and when Consumer (i.e. PCE) Very lightweight BGP implementation Not drowned by network updates

Existing Tools - VNTM Virtual link is tunnel provided by link in lower layer (e.g., virtual MPLS-TE link made by optical circuit) Virtual topology is nodes, links, and virtual links Virtual Network Topology Manager An architectural component Responsible for coordinating between layers Integrates between PCEs at different layers Applies policies to create “on-demand” topology

Additional SDN Function Network Application Applications need to dynamically: Augment routing, based on: Policy Flow and application awareness Time and external changes With knowledge of: Topology (active & potential) Network events Traffic measurement Etc. IRS Feedback Loop: Control & Information

New Tools – Interface to the Routing System Data models for routing and signaling state RIB Layer: unicast RIBs, multicast RIBs, MPLS LFIB, etc. Protocols: ISIS, OSPF, BGP, RSVP-TE, LDP, PIM, mLDP, etc. Related Function: policy-based routing, QoS, OAM, security, etc. Framework for integrating external data into routing Indirection, policy, loop-detection Filtered events for triggers, verification, and learning about changes to router state Data models for state Topology model, interface, measurements, etc. Device-level and network-level interfaces and protocols

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

IRS Requirements Programmability Stateless communications (RESTful) Easy to write an API Stateless communications (RESTful) Reduced session state No state retention between messages High throughput and highly responsive Does not require configuration to be reprocessed Multiple simultaneous asynchronous operations Multi-channel (readers/writers) Duplex communication Asynchronous, filtered events Topology information (IGP, BGP, VPN, active/potential) Easy encoding of data Parsable Extensible Standardised

IRS Work in Progress in the IETF Nine Internet-Drafts for IRS IETF-85 Atlanta, Georgia, 3-9 November 2012 IRS Birds of a Feather (BoF) Establish architectural view Investigate use cases and requirements Determine level of support to do real work Form an IETF Working Group Need to select the key use cases Agree a charter Appoint chairs Target date early 2013 Rename to stop frightening the Cousins I2RS

IRS Working Group - Scope and Work Architecture Requirements Details of selected use cases Information models for use cases Analysis of existing tools and protocols Re-Charter required before further work Work on protocols (extensions or new protocols) Select or invent encoding language Develop data models Join the discussions and contribute to the work http://www.ietf.org/mailman/irs-discuss

Integrating the Toolkit Re-use of tools is efficient and timely Leverage existing developments SDN problem space demands many functions Make use of all the tools in the toolkit Build new tools to fill the gaps Application-Based Network Operation (ABNO) An SDN Toolbox Architecture Facilitate high-function network operation Integrate all of the existing features Create a framework for IRS

Application-Based Network Operation SDN tools provide high-function, but low granularity There is a need to coordinate SDN operation to provide service-level features Some components already exist or are proposed Orchestrators OpenFlow Controllers Routing protocols Config daemons IRS Client Virtual Network Topology Manager Need a wider architecture to pull the tools together A framework in which the SDN components operate

ABNO Framework NMS/OSS Application/Service Requester ABNO Controller IRS Agent IRS/PCEP Virtual Network Topology Manager Off-Board Routing Protocol Network Policy PCE Resource Manager TED OpenFlow/Forces PCEP BGP-LS Network IRS Config/Netconf OpenFlow/Forces Routers

Toolbox Example : Virtual Topology Cannot address a service request in IP/MPLS network Create a connection in an under-lying optical network Make a virtual link to enable the service Traffic demand Service request ABNO Controller BGP-LS TEDB PCEP IGP-TE PCE PCEP IRS Virtual Link RSVP-TE Policy VNTM OpenFlow & ForCES IRS PCEP IRS GMPLS PCE TEDB IGP-TE

Summary Basic SDN function available today OpenFlow, ForCES Existing tools for advanced SDN function PCE, BGP-LS, VNTM, Netconf Advanced SDN function Programmable access to core router function Available as the Interface to the Routing System (IRS) Integration of the toolkit Chiefly and architectural task Application-Based Network Operation (ABNO)

Questions? adrian@olddog.co.uk afarrel@juniper.net