TCP/IP Protocol Suite
TCP - Transmission Control Protocol
A connection-oriented protocol that offers flow control, sequencing, and retransmission of dropped packets Transport Layer (Layer 4)
UDP - User Datagram Protocol
A connectionless alternative to TCP used for applications that do not require the functions offered by TCP. Transport Layer (Layer 4)
IP - Internet Protocol
A connectionless protocol used to move data around a network Network Layer (Layer 3)
TFTP - Trivial File Transfer Protocol
A file transfer protocol that does not have the security or error checking of FTP. Uses UDP as a transport protocol and therefore is connectionless. Application Layer (Layer 7) UDP Port 69
SMTP - Simple Mail Transfer Protocol
A mechanism for transporting emails across networks. Application Layer (Layer 7) TCP Port 25
HTTPS - Hypertext Transfer Protocol Secure
A secure protocol for retrieving files from a web server Application Layer (Layer 7) TCP Port 443
TLS - Transport Layer Security
A security protocol designed to ensure privacy between communicating client/server applications. Works at Presentation Layer (Layer 6) Initialized at Session Layer (Layer 5)
LDAP - Lightweight Directory Access Protocol
Accesses and queries directory services systems such as Novell Directory Services and Microsoft Active Directory Application Layer (Layer 7) TCP Port 389
SIP - Session Intitiation Protocol
An application layer protocol designed to establish and maintain multimedia sessions such as Internet telephony calls. Application Layer (Layer 7) TCP/UDP Port 5060
NTP - Network Time Protocol
Communicates time synchronization information between devices Application Layer (Layer 2) UDP Port 123
SCP - Secure Copy Protocol
Enables files to be copied securely between two systems. Uses SSH technology for encryption. Application Layer (Layer 7) TCP/UDP Port 22
SSH - Secure Shell
Enables secure sessions to be opened on a remote host Application Layer (Layer 7) TCP/UDP Port 22
Telnet
Enables sessions to be opened on a remote host Application Layer (Layer 7) TCP/UDP Port 23
NNTP - Network News Transfer Protocol
Facilitates the access and downloading of messages from newsgroup servers. Application Layer (Layer 7) TCP Port 119
IGMP - Internet Group Message Protocol
Provides a mechanism for systems within the same multicast group to register and communicate with each other. Network Layer (Layer 3)
ARP - Address Resolution Protocol
Resolves IP addresses to MAC addresses to enable communication between devices Data Link Layer (Layer 2)
RARP - Reverse Address Resolution Protocol
Resolves MAC addresses to IP addressses. Data Link Layer (Layer 2)
POP3/IMAP4 - Post Office Protocol 3/Internet Message Access Protocol 4
Retrieves email from a server on which it is stored. Can only retrieve mail. IMAP and POP cannot send mail Application Layer (Layer 7) TCP Port 110 and TCP Port 143 respectively
HTTP - Hypertext Transfer Protocol
Retrieves files from a web server Application Layer (Layer 7) TCP Port 80
SFTP - Secure File Transfer Protocol
Security uploads and downloads files to and from a remote host. Based on SSH security. Application Layer (Layer 7) TCP/UDP Port 22
RTP - Real-time Transport Protocol
The Internet-standard protocol for transporting real-time data Application Layer (Layer 7) TCP/UDP Port 5004
FTP - File Transfer Protocol
Uploads and downloads files to/from a remote host. Also accommodates basic file-management tasks. Application Layer (Layer 7) TCP Port 20,21
ICMP - Internet Control Message Protocol
Used on IP-based networks for error reporting, flow control, and route testing. Network Layer (Layer 3)
