Network Virtualization Sandip Chakraborty

In routing table we keep both the next hop IP (gateway) as well as the default interface. Why do we require both?

R1-eth0 R1-eth1 R2-eth0 R3-eth0 R4-eth0 1.A router may have multiple interfaces ! 2.An interface may have multiple routers connected to it ! 1.A router may have multiple interfaces ! 2.An interface may have multiple routers connected to it ! Finding a next hop essentially means finding a L3 device along with its L2 connectivity – The policies and access control get added up when we talk about routing in ISP domains! Essentially, the routers need to do a lots of “CONTROL” operations! Finding a next hop essentially means finding a L3 device along with its L2 connectivity – The policies and access control get added up when we talk about routing in ISP domains! Essentially, the routers need to do a lots of “CONTROL” operations! The Life of a Network Administrator is very tough !!!

Can we get a simple view of networking system?

Logical Similarity between Networks and Operating System Applications OS Functionalities Hardware Resources Memory, CPU, I/O Devices System Calls Applications – Process Communications Network Services Hardware Resources Physical Links, NICs, Switches Service Primitives Operating Systems Networks

Networks and Operating System – Where they Differ? Applications CENTRALIZED OS Functionalities Hardware Resources Memory, CPU, I/O Devices System Calls Applications – Process Communications Network Services Hardware Resources Physical Links, NICs, Switches Service Primitives Operating Systems Networks

Networks and Operating System – Where they Differ? Applications OS Functionalities Hardware Resources Memory, CPU, I/O Devices System Calls Applications – Process Communications Network Services Hardware Resources Physical Links, NICs, Switches Service Primitives Operating Systems Networks DISTRIBUTED CONTROLLED

Networks and Operating System – Where they Differ? Applications OS Functionalities Hardware Resources Memory, CPU, I/O Devices System Calls Applications – Process Communications Hardware Resources Physical Links, NICs, Switches Service Primitives Operating Systems Networks DISTRIBUTED CONTROLLED Network is Completely Distributed and Unsynchronized Network is Completely Distributed and Unsynchronized

How OS Manages Centralized Control over Distributed Architecture?

Network Virtualization – Decoupling Infrastructure and Service Providers Infrastructure Providers: Maintains routers, links, data centres, and other physical infrastructure Infrastructure Providers: Maintains routers, links, data centres, and other physical infrastructure Service Providers: Offer end-to-end services to users Service Providers: Offer end-to-end services to users

Example from Other Sectors Airport authority provides the infrastructure, Airline operators “rent” it and provide end-to- end services.

Solution – Network Virtualization A A A A A A A A A A A A B B B B B B B B B B B B

Packet Forwarding with Network Virtualization Competing ISPs with different goals must coordinate Single service provider controls end-to-end path Today’s Network Network Virtualization

Network Function Virtualization (NFV) Network Functions: – Routing / Forwarding – Access Control – Traffic shaping – … Implement network functions in software Load the software functions on-demand to the hardware

SOFTWARE CONTROLLER Switch ASwitch BSwitch C Flow 1 VOICE Flow 2 VIDEO Policy VO Policy VI

Putting These All Together – Software Defined Networking (SDN)

SDN Architecture – Control and Data

Control Logic

Network Administration – Things are Much Simple Now !! Fed the control logic (routing logic like routing policies, QoS control, Access control list etc) to the controller Controller will convert that logic to switch configuration (through Network virtualization)