2.1 Introduction to IP

IP protocol is like moving vans

IP effectively moves large amounts of stuff. Network topology is the road (Ethernet, DSL), truck is the IP (roads designed for truck), boxes in truck hold data (TCP, UDP in IP), boxes carry stuff inside (app info)

What parts can TCP/IP over Ethernet be broken down into?

Ehternet Header, Ethernet Payload, and Ethernet Trailer. Ethernet Payload contains IP and IP Payload. IP Payload contains TCP and the TCP Payload. TCP Payload is made of HTTP data.

What OSI layer does TCP and UDP travel on?

Layer 4, the Transport Layer. TCP and UDP is encapsulated inside IP protocol

What is multiplexing?

Communication across multiple devices, sending different types of traffic from many different applications at the same time. (UDP and TCP)

Describe TCP

Reliable protocol, can recover from errors. Connection oriented with a formal close and open of connections, acks sent to confirm received. Receiver has flow control over how much data sent. Proper data more important than speed

Describe UDP

Connectionless unreliable protocol, data sent without error recovery or acks, no flow control. Sends data faster than TCP

What does the TCP/IP refer to?

Protocols that ensure connection prior to transmission

What is UDP/IP?

Real-time communication like VOIP and video calls, connectionless protocols like DHCP

IP “truck” delivery process

IP truck delivers from one IP address to another. Boxes arrive at the address, port is written on outside of the box to tell which room it goes to

Non-ephemeral ports (permanent port numbers)

Ports 0 to 1023, usually on a server or service

Ephemeral ports - temporary port numbers

Ports 1024 to 65535, determined in realtime by the client

IPV4 sockets

Server IP address + protocol + server application port number = socket

(or client IP address + protocol + client port number)

What is the range of TCP and UDP port numbers?

0 to 65535

What type of port numbers do most servers use?

Well known non-ephemeral (not-temporary) port numbers

What are TCP and UDP?

Transport layer protocols for transmitting data over a network connection using the IP network layer protocol

What is a port?

Unique identifier number for transmission control and direction

What is a communication protocol?

A set of rules that govern communications