Networking Protocols 0.2

(ICMP) Internet Control Message Protocol

Internet Control Message Protocol (ICMP) is used for sending diagnostic or control messages between network devices, helping manage and troubleshoot network issues.

• Utilized for error reporting, such as unreachable hosts or network segments, and for operational queries like echo requests and replies (used by tools like ping)

• Operates directly on top of IP, providing feedback about issues in the communication environment without carrying application data.

(TCP) Transmission Control Protocol

Transmission Control Protocol (TCP) is a connection-oriented protocol that provides reliable, ordered, and error-checked delivery of a stream of bytes between applications running on hosts communicating via an IP network.

• Ensures that data packets are transmitted in a sequence and without errors, using acknowledgements, retransmissions, and flow control mechanism

• Used for applications where data integrity and delivery assurance are crucial, such as web browsing, email, and file transfers

  • Transport Layer

  • TCP/UDP = Transport Layer

  • More reliable

  • Garuntees data delivery

  • When downloading anything it comes in pieces

  • TCP reassembles data and checks for errors

  • Required to have reliable communication

  • Connection Oriented

  • 3 Way Hand shake

SYN →

SYN/ACK ←

ACK →

Virtual circuit <—>

• Reliable

• Connection-oriented

• Sequenced

• Acknowledgements

• Windowing flow control

• 24 - 60 bytes (high overhead)
  
  

TCP 2

• Acknowledgements: are exchanged by senders and recievers to verify and recover data transmissions.

• Flow Control prevents one host from overflowing the buffers of the other

• Windowing defines the amount of data the reciever will wait to recieve before it sends back an ACK

• Sequence numbers are used in segments to verify their order and to help recover if theres data loss

Connectionless Vs Connection-Oriented

• Connection-Oriented communication, such as that used by TCP (Transmission Control Protocol), requires a connection to be established between devices before data is exchanged, ensuring data is delivered in the correct order and retransmitted if lost, providing a reliable communication channel

• Connectionless communication, such as that used by the UDP (User Datagram Protocol, involves sending data between devices without establishing a dedicated connection, making it fast but less reliable, as delivery is not guaranteed, and data may arrive out of order

• The choice between connectionless and connection-oriented protocols depends on the applications requirements for speed, reliability, and order of data delivery

• TCP = Connection Oriented

• UPD = Connectionless

(UDP) User Datagram Protocol

• User Datagram Protocol (UDP) is a connectionless protocol that allows the transmission of data without establishing a prior connection between the sending and receiving hosts

• UDP provides a fast but less reliable method of communication, as it does not guarantee packet delivery, order, or error checking

• It is suitable for applications that require speed and efficiency over reliability, such as streaming or gaming.

(GRE) Generic Routing Encapsulation

• Generic Routing Encapsulation (GRE) is a tunneling protocol developed by Cisco that can encapsulate a wide variety of network layer protocol packet types inside IP tunnels

• GRE Creates a virtual point to point link to various brands of routers at remote points over an IP internetwork, enabling the encapsulation of packets from different protocols, making it versatile for various networking purposes

• It is commonly used for VPN’s and carrying networks that do not natively support them.

(IPSec) Internet Protocol Security

• Internet Protocol Security (IPSec) is a suite of protocols designed by authenticating and encrypting each IP packet in a data stream.

• IPSec operates in two modes: Transport mode, which encrypts the payload of each packet but leaves the header untouched, and Tunnel Mode, which encrypts both the header and payload and is used for VPN connections.

• It is widely used for securing internet communications and establishing VPN’s
  
  

Authentication Header (AH)/Encapsulating Security Payload (ESP)

• Authentication Header (AH) is a component of IPSec used for providing autentication, integrity, and nonrepudiation through digital signatures.

Encapsulating Security Payload (ESP) provides:

• Confidentiality

• Encryption
  While AH provides authentication and integrity, ESP adds encryption to ensure confidentiality of the data being transmitted.