8/9/22, 5:52 PM Chapter 2: Internet Application Protocols Application Protocols Application Protocol Function Port Number HTTP Web pages 80 HTTPS Secure Web pages 443 FTP File transfer 20, 21 SFTP Secure file transfer 22 IMAP Incoming email 143 POP3 Incoming email 110 SMTP Outgoing email 25 Telnet Terminal emulation 23 SSH Encrypted terminal emulation 22 RDP Remote Desktop 3389 SIP Voice over IP 5060 The below table does the same for utility protocols. Utility Protocols Utility Protocol Function TCP/UDP Port Number DNS Allows the use of DNS naming UDP 53 DHCP Automatic IP addressing UDP 67, 68 LDAP Querying directories TCP 389 SNMP Remote management of network devices UDP 161 TCP 445 UDP 137, 138, 139 SMB Windows (NetBIOS/NetBT) naming/folder sharing; also CIFS AFP macOS file services TCP 548 SLP Services discovery protocol TCP/UDP 427 https://ed2go-cbl.difference-engine.com/Courses/T9589-0-spt/#/student/content/1ddbbc16837ca613d2f79df1b2c22ebe?contentItemRoot=_root_ 1/1