Chapter 4.1 Flashcards
(10 cards)
What is the role of the network layer?
To deliver packets from a source host to a destination host across multiple networks, acting between the transport and data link layers.
What is forwarding in the network layer?
The process of moving packets from an input link to the correct output link at a router. It is fast and done in hardware.
What is routing in the network layer?
The process of determining the best path for a packet to travel from source to destination. It occurs less frequently and is done in software.
How are forwarding and routing related?
Routing determines the path; forwarding uses that information to move packets along the path.
What is the difference between the traditional and SDN control plane approaches?
In the traditional approach, each router runs its own routing algorithm. In SDN, a centralized controller manages routing and distributes forwarding tables.
What is the data plane?
The part of a router responsible for forwarding packets based on control plane decisions.
What is the control plane?
The part of the network layer responsible for computing paths and updating forwarding tables using routing algorithms.
List and explain five network service models.
Guaranteed Delivery – Packet is guaranteed to reach destination.
Guaranteed Delivery with Bounded Delay – Delivery guaranteed within a certain time.
In-Order Delivery – Packets arrive in order sent.
Guaranteed Minimal Bandwidth – Minimum bandwidth is guaranteed.
Security – Packets are encrypted for secure transmission.
What service model does the Internet network layer provide?
Best-effort service – no guarantees for delivery, order, delay, or bandwidth.
What is the function of a forwarding table in a router?
Maps destination addresses to outgoing interfaces, based on routing algorithm results.
