CSE 4344/5344 – Computer Networks Exam Review Vocabulary

Vocabulary flashcards covering key concepts, terms, and facts from the Computer Networks exam-review notes.

IP Fragmentation

Process of breaking a large IP datagram into smaller fragments so that each fits within the Maximum Transmission Unit (MTU) of a link.

Datagram (IP)

The basic, self-contained unit of data transfer in the Internet Protocol; contains header and payload and is routed independently.

Maximum Transmission Unit (MTU)

The largest packet size that can be sent across a network link without needing fragmentation.

Network ID

Portion of an IP address where all host bits are 0; identifies the network itself.

Broadcast ID

Address in which all host bits are 1 within a subnet; used to reach every host on that subnet.

Distance-Vector Routing Algorithm

Distributed routing method where each router advertises its distance vector to neighbors and updates routes based on neighbors’ vectors.

Periodic Update (DV)

Feature of Distance-Vector routing whereby a router sends its routing table to neighbors at regular intervals even if no change occurred.

Link-State Routing Algorithm

Routing method in which every router floods link-state information, builds a complete network map, and runs Dijkstra to compute shortest paths.

Router Interface Broadcasting (Myth)

Incorrect idea that a router blindly forwards an incoming packet out all other interfaces; proper routers forward only to the chosen next hop.

Scheduling Algorithm – Priority

Packet-scheduler that serves queues in strict order of priority levels; higher priority packets transmit first.

Scheduling Algorithm – Round Robin

Scheduler that services each active queue in cyclic order, giving equal transmission opportunity per round.

Scheduling Algorithm – Weighted Fair Queueing (WFQ)

Fair-share scheduler that allocates bandwidth to queues proportionally to assigned weights.

Scheduling Algorithm – FIFO

First-In, First-Out queuing discipline; packets exit in the same order they arrive.

Class A Address Range

1.0.0.0 – 126.255.255.255 with default mask 255.0.0.0 (/8).

Class B Address Range

128.0.0.0 – 191.255.255.255 with default mask 255.255.0.0 (/16).

Class C Address Range

192.0.0.0 – 223.255.255.255 with default mask 255.255.255.0 (/24).

Smallest Host Capacity (Classful)

Class C networks support the fewest hosts (254 usable addresses) among classes A, B, and C.

Largest Network Count (Classful)

Class C provides the greatest number of distinct networks compared with Classes A and B.

Subnet Mask /26

255.255.255.192; leaves 6 bits for hosts, allowing 64 addresses (62 usable hosts) per subnet.

Subnet Mask /27

255.255.255.224; leaves 5 host bits, allowing 32 addresses (30 usable hosts) per subnet.

Broadcast Address Calculation (/29)

For network 192.168.10.0/29, broadcast address is 192.168.10.7 (last address in the 8-address block).

Subnet (Definition)

Group of IP devices sharing the same network prefix so they can communicate without an intermediate router.

Head-of-Line (HOL) Blocking

Situation where the first packet in an input queue prevents later packets from being forwarded even if their output port is free.

Control Plane

Router component responsible for global network logic—computing and installing forwarding tables via routing protocols or SDN controllers.

Data Plane

Router component that locally forwards incoming packets to output ports using the forwarding table (longest prefix match).

Longest Prefix Matching

Lookup strategy in which the routing entry with the most specific (longest) matching prefix is chosen for a packet’s destination IP.

Prefix Forwarding Table

Router table comprising entries of IP prefixes and outgoing interfaces used to forward packets via longest prefix match.

Subnetting (Bit Borrowing)

Technique of taking bits from the host field of an address to create additional network prefixes (subnets).

/22 Network (192.168.0.0/22)

Aggregates four /24 class-C networks; borrowing 3 host bits gives /25 subnets suitable for eight subnets with ≥20 hosts each.

HOL Blocking Impact

Can reduce switch throughput to at most ~58% under certain traffic patterns, motivating crossbar and virtual output queuing designs.