Application layer 163 · codes (e.g., ASCII, EBCDIC). If the two sides of a communication use a differ- ent encoding, a translation is necessary to avoid corruption of data. Similarly, different hardware architectures use varying representations for numbers (e.g., big-endian, little-endian), and translation is necessary to ensure correct interpre- tation by the application. Note that translation services can also be implemented for more complex data structures (e.g., strings, XML content). Encryption/compression: Encryption/decryption and compression/decompres- sion can be seen as one form of translation. However, these functions do not simply translate from one data format to another, but convert data into an inter- mediate format (ciphertext or compressed data) for transmission over the net- work. Note that encryption can also be performed in other layers of the protocol stack (see Chapter 10). Application layer The application layer, in this case the sublayer corresponding to OSI layer 7, performs all processing related to communication between distributed end-system applications not handled in any of the other layers. The functionality implemented at this layer is often very specific to a particular distributed application. Thus, no general service is provided by this layer. Instead, application-specific protocols