Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Network Virtualization


Published on

This presentation describes about the fundamentals of network virtualization concepts

Published in: Internet
  • Login to see the comments

Network Virtualization

  1. 1. Network Virtualization S. Kingston Smiler (
  2. 2. Agenda Need for Network Virtualization Enablers of Network Virtualization Overlay & Underlay Network Virtual Tenant Network Underlay Network Overlay Network Use Cases
  3. 3. Introduction • Process of segregating the user traffic from one group of user is getting forwarded into the same group of user without any logical isolation of the network infrastructure • Example VLAN, VRF etc Definition 1 • Process of splitting the physical network entities like Switches, Routers, Firewall etc into multiple logical network entities for isolating the user traffic from different instances • Example VTN Definition 2
  4. 4. Need For Network Virtualization
  5. 5. Why Network Virtualization? Efficient, Flexible and scalable usage of network Logically segregating the underlay administrative domain with the overlay domain To accommodate the dynamic nature of server virtualization Providing security and isolation of traffic and network details from one user to another To Cope Up with the virtualization techniques in other areas (Compute and Storage)
  6. 6. Traditional Computing Vs Modern Computing
  7. 7. Computing Provisioning Methods Source: Adopted from Transforming the Network With Open SDN by Big Switch Network
  8. 8. Modern Networking Complexity Ref: Javvin
  9. 9. Networking Provisioning Methods Source: Adopted from Transforming the Network With Open SDN by Big Switch Network
  10. 10. Computing Vs Networking Source: Adopted from Transforming the Network With Open SDN by Big Switch Network
  11. 11. Computing Vs Networking Source: Adopted from
  12. 12. Enablers For Network Virtualization
  13. 13. Key NV Enablers Cloud and Server Virtualizati on SDN NFV
  14. 14. Data Center Cloud
  15. 15. Cloud Requirement • Three Tier Application Architecture • Each Tier has group of servers, wherein the services are deployed either in VM / containers. • VMs are not treated as legacy servers in the networking world • East-West traffic is poorly managed 15 Web Tier Application Tier Database Tier
  16. 16. SDN
  17. 17. SDN Definition Centralization of control of the network Separation of control logic to off- device compute, that Enables automation and orchestration of network services Open programmatic interfaces SDN Benefits Efficiency: optimize existing applications, services, and infrastructure Scale: rapidly grow existing applications and services Innovation: create and deliver new types of applications and services and business models What is SDN? 17Source: Adopted from SDN Central (Software-Defined Networking (SDN) Use Cases)
  18. 18. What is SDN? 18
  19. 19. SDN Innovation & Components 19 SDN Controller/ Network Operating System App App App App OpenFlow Packet-Forwarding Hardware OpenFlow compliant OS Packet-Forwarding Hardware OpenFlow compliant OS Packet-Forwarding Hardware OpenFlow compliant OS Well-defined Open API Source: Adopted from SDN Central (Software-Defined Networking (SDN) Use Cases)
  20. 20. 20SDN Central SDN Approach
  21. 21. Current Network Vs OpenFlow Vs SDN Network
  22. 22. Server Abstraction Vs SDN Abstraction 22SDN Central
  23. 23. SDN – Game changer? 23 • Complete removal of control plane may be harmful. Exact division of control plane between centralized controller and distributed forwarders is yet to be worked out. • SDN is easy if control plane is centralized but not necessary. Distributed solutions may be required for legacy equipment and for fail-safe operation. Source: Adopted from Introduction to Software Defined Software Defined Networking (SDN) Networking (SDN) by Prof. Raj Jain
  24. 24. Key Attributes for SDN Success Architecture for a Network Operating System with a service/application oriented namespace Resource virtualization, elasticity and aggregation (pooling to achieve scaling) Appropriate abstractions to foster simplification Decouple topology, traffic and inter-layer dependencies Dynamic multi-layer networking
  25. 25. SDN – Challenges 25
  26. 26. NFV
  27. 27. What is NFV? 27  Network Functions Virtualization (NFV) is a network architecture concept that proposes using IT virtualization related technologies, to virtualize entire classes of network node functions into building blocks that may be connected, or chained, together to create communication services.  Concept of NFV originated from SDN.  NFV and SDN are complementary. One does not depend upon the other. You can do SDN only, NFV only, or SDN and NFV together.  Specification comes from ETSI Industry Specification Group.
  28. 28. Part III - Open Flow Applications 28 NFV vs SDN Source: Adopted from
  29. 29. 29 NFV Innovations Source: Adopted from SDN and NFV: Facts, Extensions, and Carrier Opportunities by Prof. Raj Jain
  30. 30. Network Virtualization Concepts
  31. 31. Classifications of Network Virtualization Network Virtualization Device Level Virtual Interface NIC TUN/TAP Interface Bridge, OVS Virtual Router Network Level Network Slicing / VTN Packet Level VLAN 802.1X 802.1AD MPLS VPN L2VPN L3VPN Interface Level VRF-lite OpenFlow SIN
  32. 32. In-Device Virtualization  In-Device Network Virtualization  vNIC  vBridge  OVS  TUN/TAP
  33. 33. Packet Level Virtualization  The packet carries information related to a set of user for isolation network traffic.  Example is VLAN, L2VPN, L3PVN etc  In VLAN case, the packet will carry the VLAN tag which is used to limit the broadcast domain of a switch / bridge  The traffic which is flowing from a user from one VLAN will not be forwarded to other VLAN
  34. 34. Interface Level Virtualization  In this case the traffic isolation is provided by assigning set of ports or interface to a particular customer.  The packets from these ports will be only forwarded to the interface which is part of the same VRF.  Very good example is VRF- lite
  35. 35. Network Level Virtualization  In Network Level Virtualization, the entire physical network is sliced into multiple logical networks each assigning to a customer / group of customer.  This kind of network is termed as virtual tenant network (VTN) The network slices are mapped to a customer / tenant and hence termed as VTN
  36. 36. VTN Concepts Hypervisor Underlay Overlay
  37. 37. Underlay Networks  Underlay network comprises of the physical network devices like hubs, switches, routers.  Underlay network provides the backbone or foundation for the overlay network.  Typically underlay network is a L3 network which runs BGP / OSPF for exchanging the complete route information  Will have reachability information to all the network nodes until the physical server.
  38. 38. Overlay Networks  It’s a virtual network of nodes and logical link built on top of one or more networks  Provides additional level of virtualization to the network without any redesign.  Doesn’t impose any additional overhead to the underlay network.  Requires underlay network
  39. 39. 39 Overlays v Underlays VXLAN disassociates workloads from physical networks, allowing for possible transition to cloud based providers
  40. 40. Overlay Technologies Overlay Technologies Traditional SP MPLS Tunneling Carrier Ethernet GRE Data Center Centric VxLAN NvGRE STT SDN SDN Fabric
  41. 41. Types of Overlays Overlay Types Physical Overlay Traditional SP Overlays Virtual Overlay Data Center Centric Overlays Hybrid Overlay Data Center Centric Overlays
  42. 42. Physical Overlay (MPLS Tunneling) The Overlay Starts from the physical device. The starting node of the overlay is also part of the underlay
  43. 43. Virtual Overlay (VxLAN) The Overlay Starts from the virtual device. Virtual Access Core IP Backbone Aggregation Access Hosts VM OS VM OS Virtual Physical
  44. 44. Hybrid Overlay (VxLAN Gateway) The Overlay Starts from virtual device and ends to a physical device and vice versa Virtual Access Core IP Backbone Aggregation Access Hosts VM OS VM OS Virtual Physical
  45. 45. Use Cases
  46. 46. Data Center • Wiki – Facility used to • house computer systems (Servers, VMs, Hypervisor etc) • and associated components, such as telecommunications (Switches, Routers, Hypervisor, SAN) • and storage systems (Storage arrays, SAN) • It generally includes redundant or backup power supplies, redundant data communications connections, environmental controls (e.g., air conditioning, fire suppression) • Various security devices (Services like).
  47. 47. Datacenter Key Terminologies 47 ■ Racks (48 Servers) ■ Group of servers placed in a physical racks. Typically 48 servers will be placed in a rack. ■ Top of Rack Switch (2 per rack) ■ Network Equipment that directly connects to servers ■ EoR Switch (2 per Row) (T1) ■ Network Equipment that connects to TORs ■ Aggregation Switch (T2) ■ Network Equipment that aggregates access layer devices to provide connectivity across access layer ■ Core Layer (T3) ■ Network Equipment that interconnects multiple aggregation layer nodes
  48. 48. Data Center
  49. 49. Data Center Virtualization
  50. 50. Network Virtualization in TELCO
  51. 51. Network Virtualization in TELCO
  52. 52. Thank you