Software Defined Networking & Network Function Virtualization: evolution, opportunities, challenges Giuseppe Bianchi CNIT / University of Roma Tor Vergata Credits to A. Capone for part of the slides Beba BEhavioural BAsed forwarding Giuseppe Bianchi What’s the problem? Legacy network infrastructure is too complex, too brittle, and too closed Quote from Michael Beesley, Juniper Networks Giuseppe Bianchi Figure from David Meyer, Brocade 1
Information Technology has evolved! è Yesterday ð Rigid applications, manually administered ð dedicated/physical storage and servers è Today ð Software-as-a-service ð Virtualization ð Automated updates ð Flexible workload management ð … Let’s take a similar evolution in networks à SDN (2008+) and NFV (2012+) Giuseppe Bianchi What’s the problem with ‘Classical’ Networking Distributed network functions Network-wide consistency for any “change” or new functions State distribution mechanism OS (standard protocols) Forwarding HW OS OS Forwarding Forwarding Closed HW HW platform! Router/switch/appliance Giuseppe Bianchi 2
Vertically Integrated Closed L3 Routing, L2 switching, ACL, VPNs, etc… platform! HW/SW bundled App App App Very few Control-plane can access OS code/details Data-plane Forwarding HW Hard to innovate!! Protocols guarantee interoperability… But what’s the drawback? Giuseppe Bianchi Innovation via standards… Way too many standards? Source: IETF Giuseppe Bianchi 3
Giuseppe Bianchi Vendors dominated? Source: IETF Giuseppe Bianchi 4
Standards: the aftermath è It may take years to standardize a new feature è Are standards always the best ideas??? ð Or are they perhaps also driven by non-scientific considerations? è Cost and roll-out issues è Delaying their adoption: gray periods for security, reliability, performance Giuseppe Bianchi The management nightmare è Configuration interfaces vary across: ð Different vendors ð Different devices of same vendor ð Different firmware versions of same device! ð … and bugs as well!! à 20M lines of code in some routers è SNMP fail ð Proliferation of non-standard MIBs ð Partially implemented standard MIBs ð IETF recently published a recommendation to stop producing writable MIB modules Giuseppe Bianchi 5
SDN to the rescue… è Ultimate goal: get rid of protocols! ð Scott Shenker’s 2011 talk’s title è How to: division of labor! ð Dumb data plane switches ð Standard interface towards switches à Vendor agnostic! ð Complex control tasks maintained outside the switch à Topology control, network states, etc Giuseppe Bianchi The new paradigm Software-Defined Networking Traditional networking smart, slow, (logically) centralized Programmable Switch Control-plane switch Control-plane Data-plane Control-plane Data-plane Data-plane Data-plane API to the data plane Control-plane (e.g., OpenFlow) dumb, fast Data-plane Data-plane Giuseppe Bianchi 6
Software Defined Networking App App App Programming interface CONTROLLER Logically centralized Intelligence N W E Network OS S Data plane abstraction Simple forwarding HW Simple forwarding HW Simple forwarding HW Simple forwarding HW Giuseppe Bianchi SDN breakthrough: abstracting network view Net Apps / Services: Solve Distributed Systems App Abstract Network View interface problems ONCE rather than for every protocol (e.g. Dijkstra) App Network Abstraction Global Network view abstraction App Permits programmer to focus on high level view of network state Global Network View interface Network OS: Network OS Maps high level “commands” and programmer needs into low level switch configuration HW open interface HW forwarding abstraction Simple low-level primitives to forwarding HW Simple describe packet forwarding forwarding HW Most notably, OpenFlow Simple Simple forwarding HW forwarding HW Giuseppe Bianchi 7
SDN breakthrough: abstracting network view App Abstract Network View interface Abstract network view: App Network Abstraction Permits the programmer not to bother with complex App policy settings along network paths Abstract Global Network View interface network view: A Network OS (e.g. big switch A à B abstraction) drop Global HW open interface B network view: Simple forwarding HW Simple A A à B drop forwarding HW A à B drop A à B drop Simple Simple forwarding HW forwarding HW B Source: Scott Shenker, Stanford Giuseppe Bianchi Network Functions Virtualization Independent Software Vendors Session Border Message Controller Router WAN Acceleration CDN Orchestrated, automatic remote install Carrier DPI Grade NAT hypervisors Tester/QoE Firewall monitor Generic High Volume Servers SGSN/GGSN Generic High Volume Storage BRAS Radio Network PE Router Controller Generic High Volume Classical Network Appliance Ethernet Switches Approach Giuseppe Bianchi Adapted from Bob Briscoe, BT 8
The network meets the cloud Software Provider C Provider A Provider B implemented functionality Data Center 2 Provider C Data Center 1 Low-cost Switching/routing Provider B Provider A Firewall DPI Account Storage VPN Streaming Giuseppe Bianchi The network meets the cloud Provider B Provider A Provider C Software implemented Data Center 2 functionality Data Center 1 Virtual Provider C Virtual Provider A Shared infrastructure with low-cost Virtual Provider B switching/routing Firewall DPI Account Storage VPN Streaming Giuseppe Bianchi 9
Complementary networking trends replaces physical network appliances with software virtual appliances running on commodity IT servers (strongly) reduces reduces space & Network delivery time power consumption Functions Lifecycle management Virtualisation Abstractions (e.g., intent) to simplify and automate Software network control and Open management Defined Innovation Networks Leverage R&D Network configuration from Third parties & deployment on multi-vendor equipments Competitive supply of Centralized intelligence innovative applications Giuseppe Bianchi Complementary networking trends replaces physical network appliances with software virtual appliances running on commodity IT servers Modules, interfaces, third party SW (strongly) reduces reduces space & à Greater innovation rate Network delivery time power consumption Functions Lifecycle management Virtualisation Abstractions (e.g., intent) Automation, orchestration à Reduced OPEX to simplify and automate Software network control and Open management Defined Innovation Networks Leverage R&D Network configuration from Third parties & deployment on multi-vendor equipments virtualization à Reduced CAPEX Competitive supply of Centralized intelligence innovative applications Giuseppe Bianchi 10
SDN/NFV: Why should carriers care? è Agility ð Business cycles shrink! Must move quickly, change offerings, promptly add new services when your customers face a need ð Face fierce OTT competition (and their direct offers to end customers - bypassing carriers) with their own “weapons” à current hot battlefield: M2M/IoT/MTC è Better insight and visibility into the network status ð Thanks to open standards & software-based solutions è Better support, consistency, troubleshooting ð Hard to replace iron appliances à compare with effortless upgrade of software-based virtual appliances ð Same/consistent versions in different customers’ locations with just a “click” ð Security advantages à isolation, easier policy mgmt, security appliances, etc Giuseppe Bianchi Technical Challenges (a few) è Beyond Virtual Machines à Containers à Unikernels à Lower footprint à isolation à multi-tenancy à (much!) faster o(10ms) migration/boot à … è High Performance via HW (dataplane) programmability P4 switches, EU projects BEBA/SuperFluidity, programmable state machines in OpenFlow 1.6 (?) Giuseppe Bianchi Top Figure taken from Ericsson, bottom figure taken from McKeown (Stanford) 11
Awareness Challenges è We all agree on infrastructure advantages ð Elastic scaling, just-in-time deployment, agile provisioning, automated network resilience, application-centric network services, … è But (still) limited awareness on application-level use cases and benefits - That’s also why we need to talk also outside the today’s circle! ð Note: reported benefits exceed expectation according to survey below Source: Juniper Giuseppe Bianchi Getting (a bit more) technical: a brief intro to SDN and OpenFlow Giuseppe Bianchi 12
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