CHAPTER 3Network Programming &

Applications

CECS 474 Computer Network Interoperability

Notes for Douglas E. Comer, Computer Networks and Internets (5th Edition)

Tracy Bradley Maples, Ph.D.Computer Engineering & Computer ScienceCal ifornia State University, Long Beach

Central Theme of Chapter A programmer can create Internet application software without understanding the underlying network technology or communication protocols.

 Two Paradigms of Internet Use

Applications use TCP/IP to run on the Internet. TCP offers two paradigms for data transmission:

Transmission Control Protocol (TCP) User Datagram Protocol (UDP)

Client-Server Architecture Defn: A server is an application program that waits for contact from another application. 

Defn: A client is an application program that initiates contact with a server.

Client-Server Interaction 

Client-Server Interaction 

Client-Server bottlenecks at servers can be addressed by distributed server locations or using a to Peer-to-Peer Protocols instead.

Peer-To-Peer Architectures Peer-to-Peer (p2p) architectures are created to avoid the bottlenecks that are often created in Client/Server networks. In p2p networks, the data is distributed evenly among a set of N servers, with each server providing 1/N of the data.

Application Program Interface Defn: An Application Program Interface (API) is a set of high-level operations available for use by an application programmer. The API specifies the arguments for each operation as well as the semantics. Most client-server applications are written using API’s that are written specifically for network communication.