Abstract: Method, appartus and program products for persistent cache synchronization for communications over an external communication link between a client protocol conversion application executing on a first computer and a server protocol conversion application executing on a second computer located remote from the first computer are provided. Protocol conversion applications are provided on both the host side and the terminal side of the external communication link to provide communications over the external communication link using a differenced communication data stream which includes a reduced volume of data for transmittal. A checkpoint is provided to allow for improved performance on start up of a new communication session over the external communication link between the client application and the server application by initiating a checkpoint request and transmitting the request from the client to the server.

Abstract: A session is established between a terminal and host, each of which are operative to communicate according to a communications protocol. A communications channel is established between the terminal and the host via a client and a server of a communications network, the client being connected to the terminal and the server being connected to the host. Terminal type information is communicated from the client to the server via the communications channel. An indication of readiness to communicate data between the terminal and the host is communicated between the server and the client via the communications channel.