The Role of Internet Character Oriented Application Protocols

The Role of Internet Character -Oriented Application Protocols in an Elementary Communication Protocols Course Drago Hercog University of Ljubljana Faculty of Electrical Engineering Ljubljana, Slovenia Drago. Hercog@fe. uni-lj. si ICEE'05, Gliwice, Poland Drago Hercog

Different viewpoints of a communication system ICEE'05, Gliwice, Poland Drago Hercog 1

Communication protocols z. Implement communication system operation z. Protocol messages ybit-oriented ycharacter-oriented z. Rules for message exchange z. Not easy to be understood z. Need for understanding and experience ICEE'05, Gliwice, Poland Drago Hercog 2

Internet zworld-wide communication network zeasily available zno need for expensive equipment zwell-known from user’s point of view zcan serve as a laboratory for telecommunications students ICEE'05, Gliwice, Poland Drago Hercog 3

Protocols in Internet application layer transport layer internet layer access to network ICEE'05, Gliwice, Poland Drago Hercog 4

Application layer protocols application layer transport layer internet layer access to network ICEE'05, Gliwice, Poland z client-server oriented yrequests & replies z character-oriented z addressed by port numbers z Examples: ytelnet y. SMTP, POP 3, IMAP y. FTP Drago Hercog y. HTTP 5

Transport layer protocol: TCP application layer transport layer internet layer access to network ICEE'05, Gliwice, Poland z most frequently used z provides for connection betwen two endpoints z connection identified by ytwo IP addresses ytwo port numbers Drago Hercog 6

How to manually open a TCP connection zuse of telnet program computer address ICEE'05, Gliwice, Poland Drago Hercog set local echo port number 7

Student-to-server communication ICEE'05, Gliwice, Poland Drago Hercog 8

A simple Internet mail system Experiments can easily be done with protocols SMTP and POP 3 ! ICEE'05, Gliwice, Poland Drago Hercog 9

Sending an e-mail using SMTP protocol directly ICEE'05, Gliwice, Poland Drago Hercog 10

Retreiving an e-mail using POP 3 ICEE'05, Gliwice, Poland Drago Hercog 11

Conclusion z. Experiments yare simple ypedagogically powerful yprovide experience with both protocol messages and protocol rules yrequire only few inexpensive resources ycan be carried out with different application-layer protocols ICEE'05, Gliwice, Poland Drago Hercog 12

Thank you for your attention! ICEE'05, Gliwice, Poland Drago Hercog 13