www.isocore.com/mpls2013

Realizing a Multi-Layer Transport SDN:

Practical Considerations and

Implementation Experiences

Chris Liou

Infinera

cliou@infinera.com

The Evolving Optical Core

• Age of Virtualization – storage, compute, network

• Varying, often dynamic, traffic patterns & profiles

• Integration & orchestration of Network & IT

Data Center & Virtualization

• Industry moving to 100Gb coherent technology

• Optical Super-channels & Flexible Grid emerging

• Ethernet service rates increasing, but services no longer equivalent to ls

Core Optical

Technologies

• Transport layer convergence (POTN) simplifying networks

• Intelligent traffic mgmt & engineering enabling new flexibility, new architectural options

• Emerging SDN solutions enable new control capabilities

Capacity & Bandwidth

Management

Multi-Layer Networking Challenges

• Network layers operating in isolation

• Local optimization ≠ Global optimization

• Cross-layer awareness & intelligence essential

• Commercial implementation of inter-layer control plane lacking

• Network operators dependent on equipment vendor control plane

• Multi-vendor, multi-layer integration lacks standardization

• Vendor specificity without common abstraction & protocols untenable

• Proprietary vendor multi-layer solutions limits evolution & innovation

Vendor

W

Vendor

Z

Vendor

X

Vendor

Y

Transport

Network Layer

IP/MPLS

Network Layer

?

How can Carrier SDN help?

• Programmable networking capabilities • On-demand bandwidth services

• increases utilization efficiency while enabling rapid innovation

• Network abstractions & virtualization • Abstract specifics from higher layers

• Challenge: Least Common Denominator vs Greatest Common Factor

• Open standardized interfaces and protocols • Encourages multi-vendor environment, accessible by a broader

ecosystem

• Global network view • Centralized topology key for inter-layer coordination & optimization

• Enables automation across multi-layer, multi-vendor networks

What is needed to realize SDN in multi-layer networks?

Transport SDN – The Missing Link

Network Services Applications

Multi-layer, Multi-vendor, Multi-domain

SDN Controller

Network Virtualization

IT/Cloud

Orchestration

Business

Applications

Other

SDN Control Solutions

Application NBI

On-demand Bandwidth

Simplify/Automate Operations

Improve Resource Utilization

Speed New Service Deployment

SDN Control,

Virtualization &

Applications

Data Center Converged P-OTN

Packet, OTN, Optics

evolution

• Vanilla OpenFlow

protocol leveraged

for provisioning

• REST/JSON API for

configuration &

management

• Runs on or off NE

• Administrator defined

abstraction

• Embeds open

control onto the

platform

Open Transport Switch Light-weight Virtual Transport Switch

OTS-Mgmt

Agent

OTS-Discovery

Agent

OTS-Data

Agent OTS

Management &

Configuration Discovery &

Monitoring

Provisioning

Transport SDN Control Layer

REST/JSON OpenFlow

protocol

Converged Transport HW System

V i r t u a l i z a t i o n m a p p i n g

OTS enables open interface, user request mediation, & network

virtualization

Virtual Network Representation • OTSNode

• Logical (virtual) transport system

with switching capability & capacity

• OTSPort

• Logical ports for service

connectivity that map to physical

port resources

• Not all physical ports are SDN

enabled

• OTSLink

• Generalized topological bandwidth

link between OTSs that maps to

physical resources

• Supports logical ports plus link

attributes

Virtual Network 2

Physical Transport Network

ESnet/Infinera Multi-Layer SDN Architecture

OpenFlow &

REST/JSON

OpenFlow

OTS Config

Manager

L0/L1

Topology Multi-Layer

Path Engine

Multi-Layer

Provisioning

Multi-Layer

Topology App

Circuits Reservation System (OSCARS)

SDN Controller

Floodlight

Traffic

Optimization

Engine

WDM/

OTN/

Packet

OTS Virtualization

Multi-Layer

SDN Control

Layer

Infinera DTN-X

Host A Host B

Unified control plane approach for Packet & Optical network layers

Multi-vendor

L2/L3 Layer

Converged Optical

Transport Layer

Multi-Layer Provisioning & Optimization Demonstration

Host A Host B Host A Host B

100G

Host A Host B

Initial Configuration

10G 10G

• 2 10G circuits: routers

A-B & B-C

• 4 flows created from

A-B-C, using 4 10G

ports on Hosts

• Aggregate BW < 10G

A

B

C

Dynamic ML Provisioning

• 1 flow grows

substantially (UDP)

• Traffic optimizer

triggers new BW add

• ML controller

dynamically creates

new 100G circuit

• Redirects packet flow

to new circuit

Dynamic ML Optimization

• Flows uniformly

increase but <10G

aggregate

• Traffic optimizer

triggers router bypass

• ML controller

dynamically re-

provisions 10G circuit

w/ flows to bypass B

• What are SDN’s real objectives?

• Fine-granular programmable networking flows

• Global network view

• Centralized control program

• Standard, common forwarding & control abstraction

• Optical GMPLS seamlessly co-exists with programmable connectivity

today

• Connection oriented (TDM) services model

• Optional route computation

• Programmable circuit paths (TE) or nodal cross-connects

• Integrated signaling with ACID properties eases provisioning

• Transport SDN advocates leveraging (not replacing) GMPLS

• Direct Mode – nodal-level abstraction of connectivity

• Implicit Mode – domain-level abstraction of connectivity (w/ optional TE)

Role of GMPLS in Transport SDN

• Virtualization & multi-tenancy apply well to transport layer, but

requires different modeling

• E.g., addressing, hierarchy, resource tracking, logical port

alignment

• OpenFlow protocol compatible but requires extensions

• Transport layer topology discovery likely vendor & domain specific

• ACID properties across southbound API important in transport

• Synchronization capabilities needed between logical & physical layers

• Lifecycle management & resilience important for deployability

• Co-existence with GMPLS requires “full disclosure” to OpenFlow

What We’ve Learned

• Carrier SDN has significant benefits:

• Multi-layer, multi-domain operation

• Operationalizes transport layer’s flexibility & agility

• Virtualization of network resources

• OTS & GMPLS play key roles

• Open programmability & transport abstraction

• GMPLS facilitates higher level abstraction & carrier migration

• Transport platform & SDN requirements must harmonize

• Service-ready capacity

• Deterministic digital operations

Closing Remarks