COSC203 - PART IV Flashcards
What are two network-layer functions?
Routing and forwarding
In SDN, forwarding is performed at the ___ plane, and routing is performed at the _____ plane.
Data, control
This is at traditional approach for the network control plane.
Per-router control.
This type of networking enables logically centralised control by defining a control and data plane.
Software defined networking
What is considered a “good” route?
Least cost, fastest, and least congested.
What are the four routing algorithm classifications?
Global, static, dynamic, and decentralised.
What are two characteristics about link state routing?
centralised - link costs are known to all nodes,
and iterative - after k iterations, the least cost path to k destinations is known.
Notation for the current estimate of the least-cost-path from source to destination v
D(v)
The notation for the predecessor node along path from source to v
p(v)
This notation for a set of nodes whose least-cost-path is definitively known
N’
This is a group of networks and routers controlled by a single administrative authority
Autonomous system
This protocol is used by hosts and routers to communicate network-level information
ICMP (Internet Control Message Protocol)
What is the responsibility of the data link layer?
Transfer datagram from one node to physically adjacent node over a link
What is the difference on flow control between the transport and link layers?
Transport is end-to-end and byte-oriented.
Link layer is single link and frame-oriented.
What is the principle of error detection in flow control at the link layer?
Add additional bit(s) to detect and correct bit errors (i.e. redundancy)
Can a single parity correct single bit errors?
No - only detect.
This kind of check is a more powerful error-detection coding
CRC - Cyclic Redundancy Check
This protocol is a distributed algorithm that determines how nodes share the channel
(MAC) - Medium Access Control protocol
This provides access to the channel in ‘rounds’
TDMA - Time Division Multiple Access
What is FDMA?
Frequency Division Multiple Access - it divides the channel spectrum into frequency bands
What equation is this and which routing method does it relate to?
Bellman-Ford, which is what distance vector routing is based on.
What services are performed at the data link layer?
Framing and link access.
Where is the link layer implemented?
The link layer is implemented in the network interface card or on a chip, which has a unique identifier - the MAC address.
Which layers of the OSI model have flow control?
Transport and data link layer
