Network Functions Virtualization (NFV)

(1)

Network Functions Virtualization (NFV)

Santanu Dasgupta

Sr. Consulting Engineer –Service Provider Network Architecture

(2)

2

“Network Functions” in SP Network Architecture Landscape

LTE

Smartphone

Access

xDSL

WiFi

Smartphone PC RNC

2G 3G

Ethernet

_CE

NodeB eNodeB AP

Small Cell

FAP

Gateways /

Service Edge

OSS/BSS

Subsystems and Control

Data Plane

Voice

Video

Data

Core Network Infrastructure

IMS

xDSL

HFC

PGW SGW 2/3G GGSN 2/3G SGSN MME ePDG eWAG PE

Metro Network

Infrastructure

NAT FW IPSec DPI CGN Caching Opt MSC-S MGW A-SBC I-SBC BGCF MGCF PS / RLS DRA Video ingestion DRM

Video

Network

EMS Provisioning Analytics Billing

Radius DNS DHCP S-CSCF P-CSCF I-CSCF Trans-

coding Control Cache

Policy Parental control HLR HSS ENUM TAS SMS-C

Services

OCS MMS-C RMS HCS

xDSL

DSLAM

_{DSL/ FTTX}

BNG Core Routing Metro Ethernet Biz CPE Consumer CPE Cable Modem CMTS Capacity Planning WLC SecGW HNB-GW Policy SDN Controller BGP server Metro

(3)

Virtualization of “Network Functions”

Existing Hardware / Appliance

based Network Functions (NFs)

_{VM on x86 Server Platform}

Virtualized NFs running as

Step 1: Decouple software

from underlying hardware

Step 2: Port it as a VM on

x86 Server platform running

as a Network Function

Ethernet Switches

Storage

Hypervisor

(4)

Telco Service

Providers

$$

Service

Consumers

Enterprises

Public

Sector

Consumer

$$

Cloud / OTT Service

Providers

IaaS

PaaS

SaaS

OTT

$$

many

networks,

technologies

and systems

massive growth

of IP traffic

$

$$

converged and

private networks

PPPoE

IPv4

IPv6

MPLS

MPLS-TP

OTN

DWDM

ATM

SDH

xGE

tunnel

VPN

MP-BGP

ISIS/OSPF

MPLS-TE

DHCP

EOAM

IPOAM

LACP

SNMP

CLI

XML

t revenue cost $

1. Lean & Agile OTT players with

economies of scale

2. Highly-‐automated operaEons

3. Fast-‐paced innovaEon

1. Complex and silo’d networks

2. High cost to operate

3. Lack of agility, huge Eme required to create new services

4. ExponenEal growth of bandwidth

1. User Experience

2. Cloud Centric

ConsumpEon Models /

Pay-‐as-‐you-‐go

(5)

SP’s Expectation from NFV

§

 

NFV will help them to reduce cost (TCO)

§

 

NFV will bring the much needed agility in the Service Creation & delivery process

§

 

On-boarding a new service will be much easier with NFV

§

 

SP’s can now afford to go wrong – decommissioning a failed service wont be expensive

§

 

Services now can be scaled up and down elastically

(6)

§

 

NFV –

It is a Service Provider driven Initiative.

§

 

Initiative announced at

“SDN and OpenFlow World Congress”

, Darmstadt, Oct 2012

§

 

Industry Specification Group (ISG) group within ETSI

§

 

Not defining standards -deliver white papers and liaising with standards bodies

§

 

First ETSI meeting was held in January, 2013

§

 

Technically not related to SDN, conceptually different

§

 

But may utilize SDN concepts – Programmability, Orchestration

§

 

Type of network function mostly determine where virtualization makes sense

§

 

Careful analysis is required on Network Function by Network Function

NFV = Transition of network infrastructure services to run on

virtualised compute platforms – typically x86

(7)

Key Factors To Determine Potential Virtualization Targets

Packet / Data Plane Performance Requirements

Control Plane Performance Requirements

Deviation from Standard Server build (e.g. interface type, density)

Economics of On-boarding if Virtualized

Power Efficiency requirement of the System

Development, Ease of Integration, Service Elasticity Needs

1

2

3

4

5

6

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8

The Fundamental Electrical Building Blocks

General Purpose Processors (x86, ARM, PPC)

• Wide range of capabilities (including packet processing)

• Evolving multi-core capability (10+ processors per die)

• Support virtualization and easy to program

Network Processor Units (NPUs)

• Designed for flexible packet processing

• Multi-threaded (100s) / n/w acceleration / integrated memory

• Programmable in high level languages

Fixed function ASICs

• Very low cost

• Integrated s/w, very efficient but relatively inflexible

(9)

Characteristics of Network Elements

High Capacity Plumbing:

(L0-3 : e.g. IPv4/v6, MPLS, VPNs, ACLs, optical devices

…

)

• High throughput / BW

• Many flows needing isolation, significant traffic management needed

• Stateless functions

• Mostly predictable traffic

• Interface-specific functions (2-stage forwarding)

Network Services:

(L4+ : e.g. DPI, vFW, CGN, DDOS, BNG, mobility,

…

)

• Throughput - varies

• # of flows (traffic management) – varies

• Stateful functions

• Unpredictable traffic

• No i/f-specific functions

Low compute + High BW

è

 

Good fit for NPU

è

 

Poor fit for x86/CPU

Good fit for x86/CPU

Yes (%)

No (%)

High Compute +

(10)

10

Business CPE

Service

Appliances

(L4-L7)

Core Backbone Routing,

CE Access-Aggregation

and DC switching

Wireline GWs

Home CPE

Wireless

GWs

Network Functions – Requirements & today’s approaches

CPU

Reqs

0 10Mbps

100Mbps

1Gbps

10Gbps

100Gbps

1Tbps

10Tbps

100Tbps

1Pbps

High

Low

Distributed: CPUs + Lots of NPUs

Distributed: Lots of CPUs + NPUs

Centralized:

CPU + NPU

CPU

Centralized: CPU or SoC

Variable CPU / FPGA / NPU

OSS/BSS, subsystem

and N/W control

(11)

Mapping Back to the Service Provider Landscape

LTE

Smartphone

Access

xDSL

WiFi

Smartphone PC RNC

2G 3G

Ethernet

_CE

NodeB eNodeB AP

Small Cell

FAP

Gateways /

Service Edge

OSS/BSS

Subsystems and Control

Data Plane

Voice

Video

Data

Core Network Infrastructure

IMS

xDSL

HFC

PGW SGW 2/3G GGSN 2/3G SGSN MME ePDG eWAG PE

Metro Network

Infrastructure

NAT FW IPSec DPI CGN Caching Opt MSC-S MGW A-SBC I-SBC BGCF MGCF PS / RLS DRA Video ingestion DRM

Video

Network

EMS Provisioning Analytics Billing

Radius DNS DHCP S-CSCF P-CSCF I-CSCF Trans-

coding Control Cache

Policy Parental control HLR HSS ENUM TAS SMS-C

Services

OCS MMS-C RMS HCS

xDSL

DSLAM

_{DSL/ FTTX}

BNG Core Routing Metro Ethernet Biz CPE Consumer CPE Cable Modem CMTS Capacity Planning WLC SecGW HNB-GW Policy SDN Controller BGP server Metro

Ethernet Center Data

No

Appeal

No Appeal

High

Ap

pe

al

High

Appeal

Depends

H

ig

h Ap

pe

al

Very High Appeal

High Appeal

No

Ap

pe

(12)

12

The Role of SDN and Orchestration

Partial list, just a few main ones are mentioned here

Ethernet Switching Network Underlay

Hypervisor

NAT

Firewall

DPI

Orchestration and SDN Control Function

Storage

Server 1

Server 2

Server 3

NAT

Firewall

DPI

VM / VNF Lifecycle

Management in

End-to-end manner

Network Plumbing

to orchestrate

dynamic topologies

Configuration

Management

of the VNFs

Integration with

Other DC/POD

And the WAN

OAM,

Assurance,

Analytics

(13)

Computing

Hardware

Storage

Hardware

Network

Hardware

Hardware resources

Virtualisation Layer

_{Infrastructure}

Virtualised

Manager(s)

VNF

Manager(s)

VNF 2

Orchestrator

OSS/BSS

NFVI

VNF 3

VNF 1

Other reference points

Virtual

Computing

Virtual Storage

Virtual Network

NFV Management and Orchestration

EMS 2

EMS 3

EMS 1

Service, VNF and Infrastructure Description

Or-Vi

Or-Vnfm

Vi-Vnfm

Os-Ma

Se-Ma

Ve-Vnfm

Nf-Vi

Vn-Nf

Vl-Ha

(14)

Major Service Providers Driving the ETSI NFV ISG

(15)

NFV Use Cases

• Simple ones – Virtualized Route Reflector

• Virtualized CPE for Business VPN services

• Virtualized Mobile Packet Core

• Virtualized Managed Services (CPE, FW, UTM

…

..)

• Virtualized Home CPEs

• Virtualized Gateways (BRAS, BNG, mobile gateways, Wi-Fi gateways)

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16 DCI DCI PE Web VM DB VM FW WAAS

vCPE

vFW

vWAAS

L2 NID

Backhaul

End-to-End Orchestration

DCI DCI PE Web VM DB VM FW WAAS

vFW

vESA

vWAAS

L3 CPE /

vCPE

Backhaul

End-to-End Orchestration

(17)

Business VPN CPE in a Overlay Transport Model

Cloud IPVPN with FW and Remote

Access to Internet

§

 

vFW with NAT and Policy

§

 

vFW with IPSec/SSL Remote Access

including Remote End-Host posture

verification

CPE

Internet Router vFW

SP CLOUD

Internet

Cloud-Hosted Management

Scalable, elastic, on-demand

Overlay Packet Tunnels

§

 

Keyed IPv6 tunnels - mesh, hub&spoke;

§

 

IPSec tunnels – mesh, hub&spoke if

keyed IPv6 tunnels not supported;

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18

Where to Place the VNFs ?

§

 

Candidate location types in the network –

§

 

Centralized Data Centers à

Easier to manage

§

 

Fully Distributed – POP’s, Edge / Anchor Points / Peering locations à

Higher scale & performance

§

 

Hybrid – Mix of the above

§

 

Some factors that may need to be considered here –

§

 

The Use Case to deploy the VNFs

§

 

Cost of transporting traffic across core

§

 

Network Architecture / design

§

 

Chance of Sub-optimal routing, impact on SLA (e.g. delay)

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DCI DCI PE

L2 Backhaul

vCPE

DCI DCI Web VM DB VM FW WAAS

L2 Backhaul

Web VM DB VM FW WAAS

vCPE

DCI DCI PE

vCPE

vFW

vWAAS

L2 NID /

L2 Backhaul

Web VM DB VM FW WAAS

C

en

tra

lize

d

Higher Traffic Across Core

Sub-optimal routing

Higher e2e delay

Better performance / scale

More Complex to manage

Better performance / scale

More Complex to manage

D

ist

rib

ut

ed

D

ist

rib

ut

ed

w

ith

Se

rvi

ce

C

ha

in

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20

NFV – How to build / Augment Operations skillsets

• Most existing technologies, protocols and associated skills is equally required

• On top of that, there is a need for acquisition of New Skills

• x86 Server Virtualization

• Virtualization on Linux (and KVM/QEMU) Environment

• Cloud Orchestration System – OpenStack

• Virtual Switches – OVS, Snabbswitch, Netmap/VALE, Vendor Specific

• SDN Controllers – OpenDayLight, Vendor Specific

• Device Programmability and APIs – NETCONF, Yang, RESTCONF, REST APIs, OF

…

.

• Service Function Chaining – specially NSH (Network Service Header)

• Network based Virtual Overlay transport – VXLAN, MPLSoGRE/UDP, LISP, L2TPv3

…

..

• Management, Orchestration, OSS Fundamentals

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