Asynchronous Conversion and the N-Squared Problem(cont o If client-server software is designed to convert between the client's native data representation and the servers native data representation asymmetrically the number of versions of the software grows as the square of the number of architectures(N-Squared Conversion Problem
7 Asynchronous Conversion and the N-Squared Problem (cont.) If client-server software is designed to convert between the client’s native data representation and the server’s native data representation asymmetrically, the number of versions of the software grows as the square of the number of architectures (N-Squared Conversion Problem)
Network Standard Byte Order o The tcP/ip protocols use the same representation for all the data sent across a network in a protocol header(headers represent integer data in a standard machine-independent form) Such designs employ symmetric data converslon
8 Network Standard Byte Order The TCP/IP protocols use the same representation for all the data sent across a network in a protocol header (headers represent integer data in a standard, machine-independent form) ⚫ Such designs employ symmetric data conversion
Network Standard Byte Order(cont) o Symmetric data representation has an important consequence: only one version of protocol software 1s needed o The standard representation used for data traversing the network is known as the external data representation
9 Network Standard Byte Order (cont.) Symmetric data representation has an important consequence: only one version of protocol software is needed The standard representation used for data traversing the network is known as the external data representation
Network Standard Byte Order(cont) o The chief advantage lies in flexibility neither the client and the server needs to understand the architecture of the other o The total programming effort required vill be proportional to the number of machine architectures o The chief disadvantage of symmetric conversion is computation overhead even if the client and the server both operate at the same architecture
10 Network Standard Byte Order (cont.) The chief advantage lies in flexibility: neither the client and the server needs to understand the architecture of the other The total programming effort required will be proportional to the number of machine architectures The chief disadvantage of symmetric conversion is computation overhead even if the client and the server both operate at the same architecture
Network Standard Byte Order(cont) o Because the external representation may add information to the data or align it with word boundaries the conversion may result in a larger stream of bytes than necessary o Most programmers agree that using symmetric conversion is worthwhile 11
11 Network Standard Byte Order (cont.) Because the external representation may add information to the data or align it with word boundaries, the conversion may result in a larger stream of bytes than necessary Most programmers agree that using symmetric conversion is worthwhile