IP (Internet Protocol)

What is IP? #

• IP (Internet Protocol) is a unique address assigned to each device (computers, server equipment, smartphones, etc.) connected to the internet, enabling them to be identified.

Role of IP #

• Deliver data to the specified IP address
• Deliver data in communication units called packets

Packet Delivery Process #

• IP packet information is required: source IP, destination IP, etc.
• Client Packet Delivery: When a client attempts to deliver data to a server, it passes through multiple nodes to deliver the data to the destination IP.
• Server Packet Delivery: When a server delivers data to a client, it also sends the information to the client's IP.

Limitations of the IP Protocol #

Connectionless #

• Packet transmission even if there is no recipient or the service is unavailable

Unreliable #

• What if packets disappear midway?
• What if packets arrive out of order?

Program Differentiation #

• What if there are two or more applications running on a server using the same IP?

Resulting Problems #

Target service unavailable, packet transmission ->

1. Don't know if the target server can receive packets
2. Packet loss
3. Packet delivery order issues occur

Thus, TCP and UDP emerged.