CS6250 Exam 2 Q&A
What is the control plane responsible for? - =Contains the logic that controls the forwarding behaviors of
routers such as routing protocols and network middlebox
What is the data plane responsible for? - =Performs the actual forwarding as dictated by the control
plane
Why are the data plane and control plane separate? - =Enables us to use higher-level software programs
for control, making it easier to debug and check the networks behavior
What is forwarding? - =When a router receives a packet, it must determine what output link to send it
through
What is routing? - =Determining the path from the sender to the receiver across the network via routing
algorithms
Where are routing algorithms processed? - =Control plane
Where are forwarding functions processed? - =Data plane
What are the main components of an SDN network? - =Infrastructure, controller, and network-control
applications
What is the SDN-controlled network (infrastructure) responsible for? - =Forwarding of traffic in a
network based on rules computed by the SDN control plane
What is the SDN controller responsible for? - =Acts as an interface between the network elements and
network-control applications
What are network control applications responsible for? - =Programs that manage the underlying
network by collecting information about the network elements
, In terms of the SDN architecture, what is flow-based forwarding? - =Rules for forwarding packets can be
computed based on any number of header field values in various layers - Differs from the traditional
approach where only the destination IP determines the forwarding of a packet
What are the defining features of an SDN architecture - =Flow-based forwarding, network control
functions, programmable network
What are network control functions? - =Two components: Controller and network applications
Controller maintains up-to-date network state information about the network devices and elements (ex.
Hosts, switches, links) and provides it to network-control applications
What is a programmable network? - =The "brain" of the SDN control plane; manages the network
What plane is the SDN controller part of? - =Control plane
What are the layers of the SDN controller? - =Communication, network-wide state-management,
interface to the network-control application
In terms of the SDN controller, what does the communication layer do? - =Consists of a protocol where
the SDN controller and network controlled elements communicate
What is the nickname for the communication layer of the SDN controller? - =Southbound interface
In terms of the SDN controller, describe the network-wide state-management layer - =The network-state
that is maintained by the controllers
In terms of SDN, describe the network-control application layer - =This is how the SDN controller
interacts with network-control applications
What is another name for this layer? - =Northbound interface
What is the control plane responsible for? - =Contains the logic that controls the forwarding behaviors of
routers such as routing protocols and network middlebox
What is the data plane responsible for? - =Performs the actual forwarding as dictated by the control
plane
Why are the data plane and control plane separate? - =Enables us to use higher-level software programs
for control, making it easier to debug and check the networks behavior
What is forwarding? - =When a router receives a packet, it must determine what output link to send it
through
What is routing? - =Determining the path from the sender to the receiver across the network via routing
algorithms
Where are routing algorithms processed? - =Control plane
Where are forwarding functions processed? - =Data plane
What are the main components of an SDN network? - =Infrastructure, controller, and network-control
applications
What is the SDN-controlled network (infrastructure) responsible for? - =Forwarding of traffic in a
network based on rules computed by the SDN control plane
What is the SDN controller responsible for? - =Acts as an interface between the network elements and
network-control applications
What are network control applications responsible for? - =Programs that manage the underlying
network by collecting information about the network elements
, In terms of the SDN architecture, what is flow-based forwarding? - =Rules for forwarding packets can be
computed based on any number of header field values in various layers - Differs from the traditional
approach where only the destination IP determines the forwarding of a packet
What are the defining features of an SDN architecture - =Flow-based forwarding, network control
functions, programmable network
What are network control functions? - =Two components: Controller and network applications
Controller maintains up-to-date network state information about the network devices and elements (ex.
Hosts, switches, links) and provides it to network-control applications
What is a programmable network? - =The "brain" of the SDN control plane; manages the network
What plane is the SDN controller part of? - =Control plane
What are the layers of the SDN controller? - =Communication, network-wide state-management,
interface to the network-control application
In terms of the SDN controller, what does the communication layer do? - =Consists of a protocol where
the SDN controller and network controlled elements communicate
What is the nickname for the communication layer of the SDN controller? - =Southbound interface
In terms of the SDN controller, describe the network-wide state-management layer - =The network-state
that is maintained by the controllers
In terms of SDN, describe the network-control application layer - =This is how the SDN controller
interacts with network-control applications
What is another name for this layer? - =Northbound interface
