Terminal emulator data stream differencing system

摘要

Method and apparatus for increasing the performance of communications of a terminal emulator application resident on a first computer and communicating over an external communication link using a terminal emulator protocol with a host application resident on a second computer remote from the first computer are provided. A protocol interceptor is provided on both the host side and the terminal emulator application side of the external communication link to provide communications over the external communication link using a differenced communication protocol data stream which includes a reduced volume of data for transmittal compared to the corresponding terminal emulator protocol data stream. The reduction in volume in the differenced communication protocol data stream is based on recognition and replacement of data segments which have previously been transmitted by the host application. The terminal emulator protocol data stream from the host application is intercepted and converted to the differenced communication protocol data stream before transmission. The differenced communication protocol data stream is received at the terminal emulator application computer and reconstructed into a terminal emulator protocol data stream which is provided to the terminal emulator application. The continuous terminal emulator protocol data stream may be segmented and calculating an identifier for each segment calculated. If the segment corresponds to a segment saved on a cache present on the receiving computer, the segment is replaced with the identifier for transmission over the external communication line. The saved segment from the cache one the receiving computer is inserted in the data stream in place of the identifier. <IMAGE>