7. OTHER ISSUES This section briefly overviews two additional areas of concern that need to be considered fora more complete understanding of the software portability problem. 7.1.1 Transportation and Data Portability We have identified two major phases of porting adaptation and transportation. So far we have focused on adaptation issues. Transportation addresses problems of physical movement of software and associated artifacts, whether by means of transportable media or a network. This phase also must contend with a number of problems of data representation. Transportation issues can be identified in several categories: Media Compatibility. There maybe no common media format between the source and target environments. Even if both accept floppy disks, for example, there are different sizes, densities, and formats. The physical drive must accept the media from a different system, and it must further understand the information that is on it. Network compatibility. A similar problem can occur if two systems are connected by a network. In this case differences in network protocols can present effective communication. Naming and file systems. The problem is more complex if the data to be transported represents a set of files for which names and relationships must be maintained. There are dozens of file system types, and no standard format for data transport. Each environment understands only a limited number of foreign file systems, and may have different rules about file naming. Data compatibility. Low level data issues may occur due to differences in character codes supported, different strategies for indicating line endings, different rules on byte order for multibyte integers, etc. The problems are more complex if data is to be transported in formats such as floating point or structures or arrays.
