What are TCP packets used for?
The transmission control protocol (TCP) is the internet standard ensuring the successful exchange of data packets between devices over a network. TCP is the underlying communication protocol for a wide variety of applications, including web servers and websites, email applications, FTP and peer-to-peer apps.
What is the name of TCP 20 and TCP 21?
File Transfer Protocol (FTP)
Table 1 Common TCP/IP Protocols and Ports
| Protocol | TCP/UDP | Port Number |
|---|---|---|
| File Transfer Protocol (FTP) (RFC 959) | TCP | 20/21 |
| Secure Shell (SSH) (RFC 4250-4256) | TCP | 22 |
| Telnet (RFC 854) | TCP | 23 |
| Simple Mail Transfer Protocol (SMTP) (RFC 5321) | TCP | 25 |
What is TCP packet?
TCP stands for Transmission Control Protocol a communications standard that enables application programs and computing devices to exchange messages over a network. It is designed to send packets across the internet and ensure the successful delivery of data and messages over networks.
How large can a UDP packet be?
65,535 bytes
The field size sets a theoretical limit of 65,535 bytes (8-byte header + 65,527 bytes of data) for a UDP datagram. However the actual limit for the data length, which is imposed by the underlying IPv4 protocol, is 65,507 bytes (65,535 bytes − 8-byte UDP header − 20-byte IP header).
How is port 21 used?
Port 21 is commonly associated with FTP. FTP has been assigned to Port 21 by the Internet Assigned Numbers Authority (IANA). This is mainly due to FTP sending data in clear text and offering an anonymous option with no password required. However, FTP is a trusted and still widely used protocol for transferring files.
What is port 22 used for in Windows?
Port 22: Remote login protocol secure shell (SSH) Port 23: Telnet, used for accessing system remotely but is not very secure. Port 25: Simple Mail Transfer Protocol (SMTP) used by e-mail servers. Port 80: Used for accessing Web servers.