1. More TCP/IP Protocols Chapter 6

2. TCP Transmission Control Protocol Connection-oriented Provides flow control Sequencing (putting the segments back in the correct order) Error detection and correction

3. Three-way Handshake Has a message to send Sending host/node Receiving host/node SYN ACK ACK Rec’d TCP three-way handshake to establish communication connection. Communication can begin once the handshake is complete. A three-way handshake is also used to end the connection.

4. Timeouts Has a message to send Sending host/node Receiving host/node SYN TCP uses timeouts so that if an acknowledgement is not received within a certain period of time, the sending host will resend. SYN

5. UDP Connectionless Fast

6. TCP v. UDP TCP Header – 14 fields UDP Header – 4 fields

7. FTP File Transfer Protocol Uploading and downloading files – including large files View contents of directories (folders) Rename and delete files (w/permissions) Uses TCP for transport/guaranteed delivery Authenticates users If files aren’t ASCII text files, transfer mode is changed to binary.

8. FTP Authentication Prompts for log-in information: Username: {person’s username} Password: {whatever password} Public FTP servers can be set up for anonymous users Username: anonymous Password: {usually e-mail address of user}

9. TFTP Trivial File Transfer Protocol No security/authentication Not as much functionality as FTP No directory navigation No deletes or renaming Simple downloads such as router software

10. SMTP Simple Mail Transfer Protocol Send mail to people (way to remember) Uses TCP Mail systems spool incoming mail on mail server so that users can read later. Usually associated with SENDING but actually works within both sending and receiving.

11. POP3 Post Office Protocol – newest version Allows users to download/receive their e-mail from their Internet mail server when they read it. Mail is usually deleted from the server as soon as it is downloaded. Hotmail, Yahoo mail are POP3 mail services

12. IMAP Internet Message Access Protocol Receiving e-mail from a local mail server (LAN) Users can preview the header and subject line to determine whether to download the message to local computer. Can be thought of as a remote file server Users can create folders and store messages using IMAP software Outlook