Consolidating Servers Same motivations for multiprotocol servers Higher risk to use a single, multiservice server, why? Consolidating many services into a single server process reduces the number of executing processes dramatically The total code required

Introduction Single thread for multiple transport protocols Motivation Server design and process structure An iterative example Concurrent multiprotocol servers

Introduction Loosely specified protocol software interface Interface functionality Conceptual interface specification · System calls Two basic approaches to network communication Basic I/ functions in Linux

Client-Server Model Software Design Concurrent Processing CSIE, NTUT, TAIWAN

Introduction Examines a de facto standard for external data representation and presentation as well as a set of library procedures used to perform data conversion Describes the general motivations for using an external data representation and the details of one particular implementation

Introduction Continues the discussion of middleware (i.e., tools and libraries programmers used to construct client-server software) Y Introduces the remote procedure call (RPC) concept, and describes a particular implementation of an rpc that uses XDr standard for data representation

Introduction X Focuses on the structure of programs that use RPC, and shows how program can be divided along procedure boundaries Introduces the stub procedure concept and a program generator tool that automates much of the code generation associated with ONC RPC

Mobile IP Discussion Overview Will cover: Why IP routing breaks under mobility Mobile IPv44 basics Some low-level- protocol details(message formats, headers, etc.) Lots more detail in the specifications(see RFC)

CONTENTS LANS POINT-TO- POINT WANS SWITCHED WANS CONNECTING DEVICES

Network is divided into several smaller subnetworks Each subnetwork(subnet) has its own subnetwork address Hierarchy in IP addressing IP addresses are designed with two levels of hierarchy