null  null

Joel Obstfeld

Distinguished Engineer

Chief Architect’s Office

17 Dec 2013

What is Network Functional Virtualization

Components and challenges

Use Cases

© 2013 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

2

NfV = Transition of network infrastructure services to run on virtualised compute platforms – typically x86

NfV Initiative

Initiative announced at

“SDN and OpenFlow World Congress”

, Darmstadt, Oct 2012

Industry Specification Group (ISG) group within ETSI

Initiative should be a 2 year effort

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

First ETSI meeting was held in January’13

Use of cloud technology to support network functions

Management, Control and Data plane components

Open

Innovation

Software

Defined

Networks

Not technically related to SDN

But may utilize SDN technology – APIs, Controllers

Primarily an SP play today

Some interest from SP-like enterprises

Network

Functions

Virtualisation

Cisco Confidential

3

© 2013 Cisco and/or its affiliates. All rights reserved.

Extract from ”Network Functions Virtualisation – Introductory White Paper

Terminology

NF: A Network Function (NF)

is a building block within an operator´s network infrastructure, which has well defined external interfaces and a well defined functional behaviour. In practical terms a Network Function is today often a network node

VNF: A Virtual Network Function (VNF)

provides exactly the same functional behaviour and interfaces as the equivalent Network Function, but is deployed in a

virtualised

environment

NFVI: The NFV-Infrastructure (NFVI)

is the totality of all hardware and software components which build up the environment in which VNF are deployed, managed and executed

NFVO: The NFV-Orchestrator (NFVO)

is a software to operate, manage and automate the distributed NFV Infrastructure. The Orchestrator has control and visibility of all VNF running inside the NFV-Infra

Cisco Confidential

4

© 2013 Cisco and/or its affiliates. All rights reserved.

Enablers

Hypervisor and cloud computing technologies

Improving x86 h/w performance and scaling

Optimised packet processing SDKs and coding techniques, e.g. DPDK, Vector Processing

Network industry standardising on Ethernet

Network automation / orchestration

Value Proposition

Reduction in CAPEX and OPEX

Faster service provisioning

Service agility

Applications

Network Components

Network Services

Network Control Elements

Cisco Confidential

5

© 2013 Cisco and/or its affiliates. All rights reserved.

NFV removes the need for ‘Big Iron’ network devices

Anything a physical network device can do, a VNF can do

Just remove your physical device and replace with X86 +

VNF

Management is so much easier!

Reality?

If only it were that simple…

© 2013 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

6

Architectural Components

Virtualised Network

Functions

Classification

+

Redirection

Function

Policy

Server

Orchestration

CPE

IP edge

Customer

Premise

Distributed DC

(standalone or on-box)

WAN

Overlay tunnel

Centralised DC

Compute

Required components and location of components will vary by use

All use cases result in => Compute + VNFs + DC virtualization + Orchestration

Re-direction use cases => Policy Server + WAN Overlay

© 2013 Cisco and/or its affiliates. All rights reserved.

Data Centre

Virtualization

+

Service chaining

Cisco Confidential

8

The challenge

Centralised vs. Distributed… Scale vs Management complexity

Centralized services – can run in centralised data centres – does it scale?

Distributed services – need to be distributed further out in the network – what is the management overhead?

Control/Management plane vs. Data/User plane services

Control Plane Services – deal with signalling and management

Examples include DNS, OSS, DHCP, Route Reflector

Data Plane Services – forwarding/manipulation of user packets

Examples include DPI, NAT, CGN, BRAS, GiLAN services

Redirected traffic vs. routed traffic service –> how the traffic gets to the service?

Redirected – a network device identifies a flow(s) and redirects it from its normal path

Routed – the traffic will naturally routed through the service

Cisco Confidential

9

© 2013 Cisco and/or its affiliates. All rights reserved.

Criteria for evaluating virtualization

VNF Definition : Provides exactly the same functional behaviour and interfaces as the equivalent Network

Function, but is deployed in a virtualised environment

Service Evaluation criterion:

Packet Performance

Infrastructure versus service

Deviation from ‘standard’ server builds

Economics / practicality of on-boarding service

© 2013 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

10

Characteristic

Throughput (BW)

Performance (pps)

Power efficiency (Gbps/W)

General Purpose

CPU

Low

Low

Low

Integration

Flexibility

System development cost & time

Low

High

Low

Custom ASIC /

NPU

High (10x)

High (10x)

High

High

Medium

High

Cisco Confidential

11

© 2013 Cisco and/or its affiliates. All rights reserved.

Virtual Machine

Bare Metal

NFV Group looking for maximum flexibility

Compute Technology

Hypervisor and ‘Generic’ Virtual Machines preferred – avoid custom device drivers

Bare metal acceptable – needed for performance reasons

NIC Mapping

Major bottleneck for packet performance therefore focus of research

Pass-through and SR-IOV technologies

Cisco Confidential

12

© 2013 Cisco and/or its affiliates. All rights reserved.

High Capacity Plumbing:

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

High throughput / BW

Many flows needing isolation, significant traffic management needed

Stateless functions

Mostly predictable traffic

Low compute + High BW

è

è

Good fit for NPU

Poor fit for x86/CPU

Interface-specific functions (2-stage forwarding)

Network Services:

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

Variable throughput

Variable # of flows (traffic management)

Stateful functions

No interface-specific functions

Yes (%)

Good fit for x86/CPU

High Compute

+ Low BW

No (%)

Poor fit for x86/CPU

Cisco Confidential

13

© 2013 Cisco and/or its affiliates. All rights reserved.

NfV Orchestration

Portal / APIs

Orchestration Controller

REST

Nova

Elastic Services Control

Glance Quantum

OpenStack

REST

Network control

Various

Virtual Services

Compute

Virtual

Network

Physical

Network

Storage

Flexible options for portal integration i.e.

Custom portal, admin portal

Top-level workflow-based orchestration capabilities i.e. cross-domain

Virtual Service lifecycle management i.e. VM instantiation/termination

More complicated network requirements than possible with Quantum

Provides both virtual machine orchestration and (simple) network orchestration

Cisco Confidential

14

© 2013 Cisco and/or its affiliates. All rights reserved.

Overall concept

Classification

+

Redirection

Function

Policy

Server

Orchestration

Internet

Svc #1

Svc #2

Overlay

Network

Virtualised services

+ service chaining

Redirector overrides the default packet forwarding to re-directing user traffic to a services infrastructure

Typically lives close to the IP edge of the network, e.g. PE, BNG, P-GW, CMTs

Under control of customer-aware policy function

Primarily required for data plane services

© 2013 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

15

Service Chain Definition

Service Chains

DNS

Service 1

DPI

Video opt

NAT

LB

DNS

DPI

Service 2

NAT

DNS

Simple Service Chains

Redirection function

Default Service

Internet

Complex Services and Service Chains

How to steer traffic through a one or more service entities composed at SW speed?

Critical for non-routed data plane services

Important for control plane services

Physical service path or carried in packet metadata?

Cisco Confidential

16

© 2013 Cisco and/or its affiliates. All rights reserved.

Service Chain Technology

VLAN1 VLAN2 VLAN3 VLAN4

VLAN6 VLAN7

Switch

6

5

4

Service

Redirection

VLAN5

Internet

VLAN8

Virtual Router

Switch

VXLAN

HDR

3

2

1 vPATH

Original Frame

Internet

Service

Redirection

Virtual Router

Service ordering determined by n/w structure

© 2013 Cisco and/or its affiliates. All rights reserved.

Service Path information

Service ordering by info in user packet

Cisco Confidential

17

Virtualized SP and 3 rd party applications / appliances

Virtualized gateways (PE, P-GW, BNG)

Virtualized Mobile Services infrastructure

© 2013 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

19

Virtualized SP and 3

rd

Party applications / appliances

Orchestration

Internet

CPE

IP edge

Streamer

NGN

DNS

Content

Ingestion

DHCP

Radius

Centralised DC

SP

infrastructure

applications running on virtualized compute resources

Centralised or distributed

Examples:

BGP Route-reflectors, Radius servers, Policy servers, DHCP servers, DNS, OSS / BSS, IMS subsystem components..

Third party applications: Third party CDN and caching capabilities

Very popular concept, already deployed by many SPs

© 2013 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

20

Virtualized Edge Gateways

Policy

Server

Orchestration

NGN

CPE vBNG

IP edge vBNG vBNG vBNG

Customer

Premise

Centralised DC

Replacement of real IP Edge device with code executing on virtualized x86 platform

Examples BNG, CMTS, Mobile components…

Two vBNG examples shown, many potential variations on theme

Cost vs complexity

Management scale challenge vs single-point of control

Internet

Cisco Confidential

21

© 2013 Cisco and/or its affiliates. All rights reserved.

Mobile Services Infrastructure

S

R

P

Q

I

12

*

L

C

0

Z

X

F

E

Y

#

Access

GGSN/

PGW

VO

A-­‐SBC

DPI Firewall

Enterprise

FW

Video Only

IMS User

Android User

Physical Appliances are complex to design because of mismatched capacities, diverse resiliency strategies, incompatible networking

Re-configuration (adding capacity or adding an appliance) is also difficult

No agility because the service chains are “hard-wired” to the APN and there is no programmability; reconfiguration requires manual operations

Cisco Confidential

22

© 2013 Cisco and/or its affiliates. All rights reserved.

Virtualised Mobile Service Infrastructure

Cloud Orchestration and Management

Signal  

12

*

5

8

0

3

9

6

Z

#

Access

GGSN/

PGW

Web  

Proxy

VO

VO

A-­‐SBC

NAT

FW

FW

DPI

FW

§

Simple reconfiguration of service chains via SDN and virtualization tools

§

§

è better vertical scaling

è horizontal scaling (adjusting capacity)

§

Simplified cost model based on subscriber count + base cost of commodity hardware

§

Need better solutions for fault tolerance and high availability based on hypervisor tools!

Cisco Confidential

23

© 2013 Cisco and/or its affiliates. All rights reserved.

Research ideas

Real performance of x86 running a full WAN routing/switching function

Large tables, ACL, QoS, policing

PPS, packet delay, packet loss under x86 and various hypervisors

Impact and performance of hypervisors for applications

Low latency packet services

CPU QoS – not just packet QOS

Orchestration techniques for NFV – absolutely key!

What is the impact of NFV on n/w design?

What are the real economics of NFV?

Cisco Confidential

25

© 2013 Cisco and/or its affiliates. All rights reserved.

Movement of Network functions to the cloud has significant potential

Control, services and data plane components

NFV is not applicable to all network applications

Service functions

High performance forwarding

NFV is an architecture rather than simply virtualizing functions

Cisco Confidential

26

© 2013 Cisco and/or its affiliates. All rights reserved.

Thank you.

© 2013 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

27

Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement