Evolution of SDN: Routing in ISP and Cloud Computing Revisited
Explore the evolution of Software Defined Networking (SDN) in the context of ISP and Cloud Computing. Delve into topics such as background routing, SDN applications, and the transition from device equality. Understand the concepts of Intra-ISP and Inter-ISP routing, OSPF distribution, OSPF drawbacks, MPLS Fast Re-Route, and MPLS core-edge differentiation in network architecture.
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Presentation Transcript
Class 3: SDN Stack Theophilus Benson
Outline Background Routing in ISP Cloud Computing SDN application stack revisited Evolution of SDN The end of device Equality
Routing In ISP Within ISP (IGP): go from ingress to egress Across ISP (EGP/BGP): figure out which egress What is next hop Which endpoint Which endpoint Which endpoint
Routing In ISP Within ISP (IGP): go from ingress to egress Across ISP (EGP/BGP): figure out which egress What is set of ISP What is set of ISP What is set of ISP What is set of ISP
Routing In ISP:OSPF Distribute reachability inform Work on IP-addresses 10.10.0/24 10.11.0/24 54.23.4/24 54.23.4/24 10.10.0/24 10.11.0/24 54.23.4/24 54.23.4/24 10.10.0/24 10.11.0/24 54.23.4/24 54.23.4/24
OSPF Draw-Backs Requires complex look: longest prefix match Requires large tables Slow to reach to failures 2 minutes 10.10.0/24 10.11.0/24 54.23.4/24 54.23.4/24 10.10.0/24 10.11.0/24 54.23.4/24 54.23.4/24 10.10.0/24 10.11.0/24 54.23.4/24 54.23.4/24
Enter-MPLS Fast Re-Route (FRR) Manually setup Back-up paths (react in milliseconds) Route on a smaller number of labels 10.10.0/24 10.11.0/24 54.23.4/24 54.24.4/24 10.10.0/24 10.11.0/24 54.23.4/24 54.24.4/24 10.10.0/24 10.11.0/24 54.23.4/24 54.24.4/24 10.10.0.0/24 10.11.0.0/24 54.23.4.0/24 54.24.4.0/24
Enter-MPLS Fast Re-Route (FRR) Manually setup Back-up paths (react in milliseconds) Route on a smaller number of labels Edge does great per-packet processing 10.10.0/24 10.11.0/24 54.23.4/24 54.24.4/24 10.10.0/24 10.11.0/24 54.23.4/24 54.24.4/24 10.10.0.0/24 10.11.0.0/24 Red label Blue label 54.23.4.0/24 54.24.4.0/24
Enter-MPLS Distinguish core from edge Edge: uses IP and classifies packet to label Core: forwards based on packet 10.10.0/24 10.11.0/24 54.23.4/24 54.24.4/24 10.10.0/24 10.11.0/24 54.23.4/24 54.24.4/24 10.10.0.0/24 10.11.0.0/24 Red label Blue label 54.23.4.0/24 54.24.4.0/24
Cloud Computing Applies virtualization technology to a data center Data Center
Cloud Computing Applies virtualization technology to a data center Allows you to run VMs for different costumers Share the physical resource Data Center Provides illusion of: Unlimited resources Need more CPU/memory? Just get more VMS!!!
Cloud Computing Virtual infrastructure, all software. Virtual machines (Virtual Servers) Virtual Switch Physical Servers Data Center Physical Switches Traditional Data Center. All Hardware.
SDN: The OpenFlow Flavor A network is Applications Applications Applications Network O.S. Switch Operating System Switch Hardware Switch Operating System Switch Hardware Switch Operating System Switch Hardware Switch Operating System Switch Hardware
SDN: The OpenFlow Flavor Flexible API allows A network supports Innovation in App Innovation in N/W O/S Hard to balance between Generality and practicality Requires all devices to be the same. But you don t need same functionality everywhere Forwarding V. Encryption V. You don t need all devices to handle the same type of traffic Cellular V. Core V. IPTV Limits evolvabilty by forcing all to evolve at same speed. Forcing device homogeneity Limits ability to move forward
Background Network infrastructure design is guided by network requirements and network interfaces Network requirements come from two sources: (i) Host : want their packets to travel to a particular destination (ii) Network operator : traffic engineering, tunneling and isolation virtualization, 15
Different Interfaces There are three relevant interfaces (i) Host -Network : inform the network of host s requirements. E,g. destination and QoS (ii) Operator-Network : inform the network of operator s requirements. E.g. configuration of network rules. (iii) Packet-Switch : identify packet to a switch 16
Evolution of Data Center Networks Operator-Network Everyone is Equal Host-Network Packet-Switch OpenFlow API OpenFlow IP- Bad config interface MPLS label addresses MPLS Fabric
Application of Fabric To Reality: The Cloud Virtual machines (Virtual Servers) Virtual Switch Physical Servers Data Center Physical Switches
Application of Fabric To Reality: The Cloud Can implement: QoS Migration monitoring Access Control Performs Classification: VM address-> server address Edge core (Think: IP MPLS) Virtual machines (Virtual Servers) OpenVirtual Switch One Big Switch abstraction. Physical Servers Data Center Abstract Away this Layer Forwards based on server IP Server IP is the Label here.
Application of Fabric To Reality: The Cloud Can implement: QoS Migration monitoring Access Control Performs Classification: VM address-> server address Edge core (Think: IP MPLS) Virtual machines (Virtual Servers) OpenVirtual Switch One Big Switch abstraction. The VM can evolve independently of the physical infrastructure. VMs can go to IPv6 while physical stays IPv4. Physical Servers Data Center Abstract Away this Layer VMs can had advance functionality added by modifying virtual switch Forwards based on server IP Server IP is the Label here.
Application of Fabric To Reality: The ISP Replace Edge switches with servers Get extreme flexibility. Easy to change code Bad scaling. Need multiple servers
Application of Fabric To Reality: The ISP Core: uses hardware label-based forwarding Edge: does classification Can do other complex processing: encryption, QoS
Routing In ISP Within ISP (IGP): go from ingress to egress Across ISP (EGP/BGP): figure out which egress What is set of ISP (BGP) What is set of ISP (BGP) What is set of ISP(BGP) What is set of ISP (BGP) bob alice EGP for distributing reachability information
Routing In ISP Running SDN in each ISP Edge controller runs BGP What is set of ISP (BGP) What is set of ISP(BGP) What is set of ISP(BGP) bob alice EGP for distributing reachability information
Routing In ISP Hybrid approach of BGP+SDN Edge controller negotiates with border routers What is set of ISP(BGP) What is set of ISP (BGP) What is set of ISP (BGP) What is set of ISP (BGP) bob alice EGP for distributing reachability information
Routing In ISP Replace the BGP with a Content Centric approach. What is closest cache closest cache What is closest cache What is bob alice
