Computer Networks: Protocols, Technologies, and Concepts

Internet Access Technologies

Dial up – phone; DSL – phone line; Cable Internet – TV Network

Delay Calculations

Propagation delay, transmission delay, store-and-forward, Bandwidth-delay product, Bandwidth-RTT product, Dnodal=dproc+dqueue+dtrans+dprop; Dtrans = L/R, L = length, R = bandwidth/rate; Dprop = d/s, d = length, s = propagation speed.

ISO/OSI Reference Model

Seven layers; TCP/IP architecture for the Internet (five layers)


3 delay measurements for each router on the way to destination, last one is destination


Persistent vs. Non-persistent

Email Application Protocols

SMTP, POP, IMAP; their underlying transport layer protocol

HTTP Request Methods


HTTP Response Status Codes

200 OK, 301 Moved permanently, 400 bad request, 404 not found, 505 HTTP version not supported

HTTP Cookie

User visits site, cookie id assigned

Web Caching

Proxy server deployed closer to clients

DNS Resource Records

How to interpret a resource record of a given type (A, NS, CNAME, MX)

Rdt (Reliable Data Transfer)

Channel error characteristics & mechanisms to handle channel errors

Sliding Window Protocols

Go-Back-N; Selective Repeat

TCP & UDP Segment Format

IP addresses, TCP port numbers, TCP sequence numbers

TCP Acknowledgement Number

Connection management scenario and general scenario

TCP Fast Retransmit

Behavior and implications

TCP Flow Control

Receiver notifies sender of free buffer space

TCP Congestion Control

Adjustment in Slow Start, Congestion Avoidance, and Fast Recovery states


Relationship between MSS and MTU

IPv4 & IPv6 Datagram Format

Address format, datagram format

Longest Prefix Matching

Convert range on forwarding table into prefix


Process and CIDR

IPv4 Datagram Fragmentation

Reassembled only at final destination


Network address translation

IP Tunneling

Transition to IPv6


Dynamic host configuration protocol

Routing Algorithms

Link state algorithm, distance vector algorithm

Inter-AS Routing (BGP)

When routers use eBGP & iBGP sessions/connections


Internet control message protocol

MAC Protocols

Channel partitioning, random access, taking turns

Binary Exponential Back-off in CSMA/CD

After the Nth collision

LAN Broadcast vs. Unicast

Comparison and usage

ARP Protocol

Finding the MAC address for a given IP address in the LAN

Ethernet Switch Self-Learning Mechanism

Switch learns hosts can be reached through which interfaces

MAC & IP Address Settings

During the process of sending a datagram from one subnet to another subnet

Hidden Terminal Problem

In a wireless setting

Comparison between Ethernet & WiFi

In terms of MAC address format, frame format, MAC protocol, etc.

Mobility Management

When a node moves from one access network to another access network