Future Internet Chapter 5: Network Function Virtualization 5a: - PowerPoint PPT Presentation

Future Internet Chapter 5: Network Function Virtualization 5a: Basics Holger Karl Computer Networks Group Universität Paderborn

Overview • Technical trends & motivation • Reference architectures: ETSI, IETF • Problems to solve • Existing projects • Conclusions SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 2

Traditional network functionality • Provider networks not only forward packets • Examples: Firewalls, deep packet inspector, load balancer, content distribution, HTTP header enrichment functions, TCP optimizer, ... • By necessity distributed inside the network • Traditionally implemented on expensive, closed boxes • Physical network function, "network appliance" SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 3

Virtualize network functionality? • Network functions are just computing • Use commmon virtualization techniques to realize them? • Commercial off-the-shelf hardware • Somewhat optimized for networking performance • Software implementations: Virtual network function (VNF) => Network Function Virtualization (NFV) • Hope: • Improved CAPEX, OPEX (energy!) • Faster deployment • Flexible management ETSI terminology SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 4

Business options? • Business model: Opened up to external partners? • Not just the network operator • Escape route from "just a bit pipe" • NFVI as a Service : Infrastructure + Network as a Service • Target? • Business between network operators • But: Not just network functions per se • Even web servers, application servers, ... ? SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 5

Some use cases from ETSI • VNFaaS: Virtualize customer premise equipment into the network • E.g., Enterprise access router, VPN termination, ... • Mobile Core/IMS functionality, mobile base stations • Virtualized home environment • Residential gateway (Internet, VoIP, firewall, NAT), set-top box for media services, personal video recorder, ... • Virtualize content distribution networks • Netflix, Akamai, ... : dynamically provision web caches/streaming proxies were needed Network Functions Virtualisation; Use Cases. ESTI GS NFV 001. SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 6

Broadening the scope: Distributing data centers • Common rationale: Economy of scale • Build huge data centers to safe money • But results in only a few centers • Consequence: data centers far away from users • Fine for many applications • Critical for some: interactive, gaming, content distribution, streaming, ... • Have some local functionality close to users? • Smaller centers, widely distributed • More expensive, more suitable? SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 7

Distributed Cloud Computing • DCC pioneered in late 2000s, under different names • Distributed Cloud Computing • Carrier cloud • In-network cloud • Nano data centers • …. • Many commonalities with NFV • Different emphasis: end-user applications vs. network-oriented features • Convergence? Open question … SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 8

Overview • Technical trends & motivation • Reference architectures: ETSI, IETF • Problems to solve • Existing projects • Conclusions SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 9

First step: Infrastructure for Network Functions • Suppose network function virtualization takes place • Results in many small data centers in the network • In total : Network Function Virtualisation Infrastructure (NFVI) • (Using ETSI terminology here, more details to come) SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 10

NFV Infrastructure • ETSI infrastructure definition • “Support deployment and execution of Virtualised Network Functions” • “Totality of the hardware and software components which build up the environment in which VNFs are deployed” • Leverage existing virtualization technology from computing • Enhance with network virtualization Infrastructure network Hypervisor domain domain Network Functions Virtualisation; Architectural Framework. ESTI GS NFV 002. Compute domain SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 11

NFVI vs. VNF • NFVI executes VNF: Separate description necessary Figure 4: Virtualisation of network function IT-industy/ cloud interfaces SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 12

NFVI: Recursion • Recursion allowed between VNF and Host Function! One specific function VNF-implementing Application Operating system in VM Virtual machine (VM) Hypervisor Recall your basic Server blade operation systems class! SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 13

NFVI & cloud technologies • Clouds provide basic technologies • Hypervisors to virtualize machines/operating systems • Virtual Ethernet switches (openVswitch, in particular) • With core functions, e.g., rapid elasticity, resource pooling • … as well as management interfaces • Typically, Web-based control of VM operations • Adopt business model of cloud computing for NFV? • On-demand self-service? • Pay-as-you-use? X-as-a-service? SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 14

Towards a big-picture architecture • Which roles do we need? • Real stuff: computing, networks, external networks • Virtual stuff: (virtual) functions running “somewhere”, tied together into virtual networks, realizing an application • Management and orchestration • Which interfaces do we need? • NFV-realized applications: run somewhere, be managed, talk to networks • Virtualization interfaces for computing and networking • Mapping, management, orchestration interfaces SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 15

Terminology • Virtual network function (VNF): • Software implementations of a network function • Packaged and executed inside a virtualisation container (e.g., VM, Docker container) • Can be decomposed into smaller execution entities, called virtual deployment units (VDU) • Not part of reference architecture • Executed on top of the NFVI . • Network service (NS): Multiple interconnected VNFs • Element manager (EM): responsible for functional management of VNFs • Translates management requests from NFV MANO to (proprietary) management interfaces of a specific VNF implementation SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 16

Terminology • NFV infrastructure (NFVI): environment on which VNF are executed • Abstracts hardware resources into virtual resources. • Offer virtual compute/storage/networking resources • E.g., virtual subnets • Allows to run complex NS on top of it • NFV orchestrator (NFVO): end-to-end management and orchestration of NS • Includes tasks like scaling, placing, and healing of NS/VNF • VNF manager (VNFM):Unlike NFVO, focuses on VNF lifecycle management • E.g., instantiation, configuration, updating, scaling, and termination • Multiple VNFMs can be deployed in an NFVO, allows to build VNF- specific orchestration solutions SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 17

Terminology • Virtual infrastructure manager (VIM) : • Manage virtualised resources provided by NFVI • Typically, NFVO/VNFM connect to multiple VIMs from different vendors using internal abstraction models, often called VIM drivers • MANO = NFVI + NFVO + VIM • Service, VNF, and infrastructure description : • To deploy an NS/VNF, MANO systems needs description of those artefacts. • Multiple standardised description approaches exist • Operation/business support system (OSS/BSS): Usually, integrated with existing OSS/BSS of an operator SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 18

Overview architecture: ETSI reference architecture SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 19

ETSI reference architecture Mano framework VIM (e.g., OpenStack, VMWare, … SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 20

Big-picture architecture Network Functions Virtualisation; Infrastructure Overview. SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 21 ESTI GS NFV-INF 001.

Big-picture architecture: Interfaces Network Functions Virtualisation; Infrastructure Overview. SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 22 ESTI GS NFV-INF 001.

ETSI Compute Domain • Computational and storage components, typically commodity of-the-shelf (COTS) • CPU, network interface (NIC), storage, chassis, … • Acceleration hardware, e.g., en-/decryption • Combined into an industry-standard “server” SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 23

ETSI Hypervisor domain • Provide an abstract machine (on top of a real server) to virtual network functions • … and to management/orchestration functions, if so desired Network Functions Virtualisation; Infrastructure Overview. SS 19, v 1.2 FI - Ch 5a: Network Function Virtualization, Basics 24 ESTI GS NFV-INF 001.