sdn in carrier networks

SDN in Carrier Networks

Saurav Das, Guru Parulkar, Nick McKeown

Broadcom27th October, 2011

Outline• Problem Statement – 2 networks

• Proposed Solution: Unified Control Architecture

• Prototype & Demonstration to validate Simplicity & Extensibility compared to existing solution

• Problem Statement – MPLS

• Proposed Solution: SDN based MPLS

Wide Area IP Network

3

5

TDM Switch

WDM Switch

40-160wavelengthschannels

Each channel runs at10 or 40 Gbps.100 Gbps coming soon!

Logical Link between two Routers over the Wide-Area

OtherClients

Physical Router Link

Physical Router Link

WDM Line System Optical Fiber

Other Clients

Transport Network

IP Network

6

7

Problem Statement

• Today, IP and Transport networks are separate• planned, designed and operated separately • by separate teams

• Owning and operating two separate networks: inefficient!

• Is there a way to run one network instead of two separate ones?

TRANSPORT Network

INTERNET

Eliminate Circuit Switching

INTERNETEnterprise Private -LinesPrivate-Nets

Cellular

PSTN

All Services

Is there a need for circuit switching in the Transport Network?

Eliminate Circuit Switching

Fundamental

Packet switching is more expensive

than Circuit switching

Circuit Switch

Phy

Scheduler

Control

TSI/(DE) MUX Phy

O/EFraming

CodingErr det/corr.

(λ, t, Port) (λ’, t’, Port’)

Input Linecard Output Linecard

Switching Fabric

Circuit Switch

Phy TSI/(DE) MUX Phy

O/EFraming

CodingErr det/corr.

(λ, t, port) (λ’, t’, port’)Input Linecard Output Linecard

PhyQoSPhy Parse Lookup MOD

Scheduler

Control

Scheduler

Control

Protocol SetPushPopDecretc.

Queuing,

Sampling

Mirroring

Hashing

Queuing

Policing

ACLs, Routing,Policy- Routing

QoS – WFQ, pQ, FIFOCongestion - RED

(pkt., port) (pkt.’, port’)

Packet Switch

Packet and Circuit SwitchesFiber Switch WDM Switch TDM Switch Packet Switch

Fabric Mux/DemuxFabric

PhyTSI

Fabric

PhyParsingLookup

ModificationsFabricACLs

QueuingPolicing

Policy RoutingCongestion Avoidance

QoSSampling & Mirroring

Hashing

Packet and Circuit Switches

Glimmerglass IOS600 Fujitsu Flashwave 7500 Ciena CoreDirector Cisco CRS-1

Fiber Switch WDM Switch TDM Switch Packet Switch

B/w 1.92 Tbps 1.6 Tbps 640 Gbps 640 Gbps




B/w 1.92 Tbps 1.6 Tbps 640 Gbps 640 Gbps

Power 85 W 360 W 1440 W 9630 W

Volume 7” x 17” x 28” 23” x 22” x 22” 84” x 26” x 21“ 84” x 24” x 36”

Price < 50 110.38 83.73 884.35




B/w 1 1 1 1

Power 1 W/Gbps 5 51 332

Volume 1 in3/Gbps 4 41 65

Price 1 $/Gbps 3 5 53

Capex Results

1

59%

17

Convergence

`

Outline• Problem Statement: want one network, not two!

convergence makes sense. but packets and circuits must work together

• Proposed Solution: Unified Control Architecture1. Common Flow Abstraction2. Common Map Abstraction

The Flow Abstraction

End – to – End Flow

L4: TCP src/dst port L3: IP src/dst addr, IP protoL2.5: L2:

Flow Identifiers

CommonDestFlow

L4: L3: IP dst prefix for ChinaL2.5: L2:

19

The Flow Abstraction

• Classification of packets that have a logical association• Action & Maintaining Flow State• Flow based Accounting & Resource Management

What is a Flow? L4: L3: IP src prefix for branchL2.5: L2:

Flow Identifiers

Common Src Flow

L4: TCP dst port 80 L3: IP protoL2.5: L2: MAC src

Web traffic from a Handset

L4: L3:L2.5: MPLS Label ID L2:

All packets between 2 routers

20

1. Common Flow Abstraction

Flow Identifiers

L1: L0: (p2, p5, p7, p9) λ5 L1: L0: (p2, p5, p7, p9) (λ5, λ8, λ3) L1: L0: (p2, λ5), (p5, λ8), (p7, λ3)

21


Flow Identifiers

L1: p3, ts6, num3 L0: L1: p3, ts6, num3 p4, ts3, num3 p7, ts9, num3L0:

22

Circuit Switch

Phy TSI/(DE) MUX Phy

PhyQoSPhy ParseLookup

MOD

Scheduler

Control

Scheduler

Control

Lookup Table

Packet Switch

Cross-Connect Table

(λ, t, port) (λ’, t’, port’)

(pkt., port) (pkt.’, port’)

Packet Switch

Packet Switch

Wavelength Switch

Time-slotSwitch

Multi-layerSwitch


L4L3L2.5L2L1L0


3 possible options But really only one (convergence) makes sense.


routing, access-control, mobility, traffic-engineering, guarantees, recovery, bandwidth-on-demand …

2. Common Map Abstraction

Unified Control Plane



L4L3L2.5L2L1L0

IP Router

EthernetSwitch

Wavelength Switch

TDMSwitch

Multi-layerSwitch

Network Functions

Tables for identifiers and actions

Flow is any combination

Network - API


Switch - API


State Collection State Dissemination & Application Isolation

Built for Performance Scale & Reliability

Unified Control Architecture




• Prototype & Demonstration to validate Simplicity & Extensibility compared to industry-solution



L4L3L2.5L2L1L0

IP Router

EthernetSwitch

Wavelength Switch

TDMSwitch

Multi-layerSwitch

Network Functions

Tables for identifiers and actions

Flow is any combination

Network - API


Switch - API


State Collection State Dissemination & Application Isolation

Built for Performance Scale & Reliability

Unified Control Architecture

Implementation of the Architecture

30

NOX

Interface: OpenFlow Protocol

Packet & Circuit Switches

Converged Network

Unified ControlPlane



Prototype

31

Hybrid Packet-Circuit Switches

Packet switches

NOX

Prototype – Emulated WAN

SANFRANCISCO

HOUSTON

NEW YORK

NOX

OpenFlow Protocol

32

GE links

OC-48 links (2.5 Gbps)

Implementation of the Architecture

33

NOX


Packet & Circuit Switches

Converged Network




Application across packet and circuits

VOIPHTTP

VOIP

HTTP

VIDEO

Example Network ApplicationControl Function: Treat different kinds of traffic differently

Function Impl.: Use both packets and circuits, at the same time.

Traffic-type Delay/Jitter Bandwidth Recovery VoIP Lowest Delay Low Medium

Video Zero Jitter High Highest

Web Best-effort Medium Lowest

35

Video of a Demonstrationof Packet-Circuit Control with OF/SDN

www.openflow.org/videos

Why is it Simpler?

36

NOX


Converged Network

4700 lines of code






Why is it Simpler?

37

NOX


Converged Network

EMS EMS EMS

Proprietary Interface Proprietary Interface

Vendor Islands

IP NetworkTransport Network

OSPF-TERSVP-TE

OSPF-TERSVP-TE

IP/MPLS Control Plane

GMPLS Control Plane

UNI

Why is it Simpler?

38

EMS EMS EMS


Vendor Islands


OSPF-TERSVP-TE

OSPF-TERSVP-TE


GMPLS Control Plane

UNI35000*45000#

15000!

45000^

35000^

Sources: * Quagga # Tequila ! MUPBED ^ DRAGON

∑ = 175,000+ LOC

68,870

~ 13.5 million

NOX

Linux kernel

Aggr. Map & Bw Rec.

4726

Linux kernel

Quagga base

OSPF RSVP logic

175,800 +

51,828

~ 13.5 million

IOS or JUNOS

OSPF RSVP logic

~ 20 million

Why is it Simpler?

Why is it Simpler?

40

Why is it the Right Abstraction?

NOX


Converged Network

4700 lines of code






41

EMS EMS EMS


Vendor Islands


OSPF-TERSVP-TE

OSPF-TERSVP-TE


GMPLS Control Plane

UNI35000*45000#

15000!

45000^

35000^

Sources: * Quagga # Tequila ! MUPBED ^ DRAGON

∑ = 175,000+ LOC


42

EMS EMS EMS


Vendor Islands


OSPF-TERSVP-TE

OSPF-TERSVP-TE


GMPLS Control Plane

UNI3500045000

15000

4500035000

∑ = 175,000 LOC


Diffserv based TE +Policy Based Routing

Can’t Specify :- route,- or delay, - or recovery mechanism- or monitoring/stats- or priorities

GoldSilverBronze

43

Why is it the Right Abstraction?Extensibility

NOX


Converged Network





1. Full View2. Control Function not tied to

Distribution Mechanism



• Proposed Solution: Unified Control Architecture

• Prototype & Demonstration to validate Simplicity & Extensibility compared to existing solution

• Problem Statement - MPLS

Why do Service Providers use MPLS?

Really about 2 services

MPLS Services

MPLS VPNs MPLS - TE

Motivation

Highly profitable

No easy way

Older ways not used

Motivation

Deterministic Behavior

Efficient Resource Utilization

Older ways not used

Motivation

LSPsIncoming packets

ClassificationInto FECs

Flow state in Head-end LER

Label Switch Router (LSR)

MPLS network

IP network

Label Switched Path (LSP)Label Edge Router (LER)

MPLS has Flow Abstraction

OSPF-TE

RSVP-TE

LDP I-BGP

LMP MP-BGP

Motivation

Label Switched Path (LSP)

1. MPLS additional feature on complex core-routers2. IP/MPLS control exceedingly complex

State Distribution Mechanisms

Switch Operating System

DistributedNetwork Functions

IGP- Route Advert, Link-State

OSPFv2

TE Label Distribution

RSVP-TE

VPN-IPv4 Route Advert

MP-BGP

E-BGP learned Route Advert

I-BGP + RR

PE Label Distribution

LDP

Distributed Network Functions each with their own

State Distribution Mechanisms


MPLS lacks Map Abstraction

Introducing Map Abstraction in MPLS

P

OSPF-TE

RSVP-TE

LDP I-BGPOpenFlow

NETWORK OPERATING SYSTEM

Routing Discovery Label Distribution Recovery

TE

LMP MP-BGP

PUSH

Simpler Data Plane

Simpler Control Plane

Services

Network Applications

Label Switched Path (LSP)

SWAP POP

Provide the Services without the Complexity!

What is Traffic Engineering?

Steering traffic to where the bandwidth is…• good for the traffic - less congestion• good for the network - better resource utilization

MPLS Solution: • Create tunnels routed over under-utilized

parts of the network • Route traffic through the tunnels

TE-LSP Features1. Auto-route

2. Auto-bandwidth

3. Priorities

4. Load-share

5. Diffserv aware Traffic Engineering (DS-TE)

6. MPLS FRR

7. Explicit Routes

8. Re-optimization timers

SDN Approach

Basic Idea• Retain MPLS data-plane operations • Replace IP/MPLS control plane• Demonstrate TE & its features • All made simpler – some greatly (eg. AutoRoute)• Some made possible only with SDN (eg. global-optimization)

IP routing (SPF)

TE-LSP routing (CSPF)

Static-routes, PBR/FBF, Autoroute

Link-state: cost, up/downTE-Link-state: weight, attributes, reservations

Link-state: cost, up/down

R3

R6

R2R4

R5

R1

AutoRoute

AutoRoute

Destination Router Next-Hop Total-Cost

R4 R4, OutIntf 12 10

R6 R6, OutIntf 9 10


R2 R6, OutIntf 9 20

Destination Router Next-Hop Total-Cost


R6 R6, OutIntf 9 10

R2 R2, OutIntf T1 20

R3

R6

R2R4

R5

R1

Automated but unwieldy – stuck with decision.

Other approaches flexible but not automated

SDN based AutoRoute

IP routing (SPF)

TE-LSP routing (CSPF)

Static-routes, PBR/FBF, Autoroute

Link-state: cost, up/downTE-Link-state: weight, attributes, reservations

Link-state: cost, up/down

Default SPF

Routing

IP network

TE-LSP Routing(CSPF)

IP network with TE tunnels

VoIP traffic

Routing

Customer traffic

Routing

Flexibility + Automation = Programmability

NOX core(Connection Handler, Event engine)

Switch-API

GUI API

(LAVI)

GUI(ENVI)

OpenFlow protocol

To switches..

Link Discovery

IP Topology

TE-LSP Routing (CSPF)

TE-LSP Configuration Bw. Res. & Priorities

Label DBTE tunnel DB

Packet-flow DB

Controller

TE Applications

Map Abstraction

Network API

TE-LSP Statistics & Auto-Bandwidth

Network API

Default SPF Routing Load SharingTraffic-type Aware Routing

Packet-flow Routing Applications

Controller Internals

Open vSwitchwith standard

MPLS data plane

Prototype System

Network Operating System (NOX)GUI (Envi)

showing real-timenetwork state

Open vSwitch(with MPLS)Open vSwitch(with MPLS)Open vSwitch(with MPLS)Open vSwitch(with MPLS)Open vSwitch(with MPLS)Open vSwitch(with MPLS)Open vSwitch(with MPLS)Open vSwitch(with MPLS)Open vSwitch(with MPLS)

Open vSwitchwith standard

MPLS data plane

OpenFlow

MPLS GUI MPLS API MPLS StatsCSPF Routing

MPLS-TEAuto – route; Auto – bandwidthTraffic – aware LSPs; PrioritiesTE-LSP configuration

Mininet Environment

58

Video of a Demonstrationshowing MPLS-TE service with SDN/OF

www.openflow.org/videos

Providing MPLS Services with SDN/OF

OpenFlow

NETWORK OPERATING SYSTEM

Routing Discovery Label Distribution Recovery

TE 2.0 VPNs 2.0

Simpler Data Plane

Simpler Control Plane

Services / Network Applications

Optimized FRR/ AutoBw

MPLS-TP Control

Multi-layer Control

SWAP POPPUSH

Source: Stuart Elby, Verizon

SDN in Carrier Networks

Control – Simplicity, Extensibility, Flexible Automated, Programmatic, and Globally-Optimized

Reduce TCO – Use circuits or MPLS or both with IP; and SDN control-architecture

Innovate – Faster pace of Innovation than today. Differentiate service-offerings from

other carriers.

Software Defined Networks

Thanks!

sdn in carrier networks

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