Gathering data handling statistics in non-synchronous data communication networks

Disclosed apparatus and method enable a host computer or server in a non-synchronous data communication network-e.g. a network in which data is subject to routing over transmission paths of indefinite configurations and lengths, and receptive handling of indefinite duration-to gather time statistics from client computers or terminals receiving the data; particularly statistics useful for determining: (a) transit times of data from server to clients; (b) times elapsed at client stations, between reception of data and one or more events pre-specified in information accompanying the data; and (c) transit times of return messages sent from respective client stations to the server. Control information attached to transmitted data includes a "timing script" written in a scripted language subject to interpretation by software at the client station receiving the data. In addition to the timing script, other information presently attached to transmitted data includes an identity ("data ID") value uniquely associated with the transmitted data, and a starting time value ST0 representing the time at which transmission of the data started. The timing script causes a computer or intelligent terminal at the client station to start a local timer, and send two or more return messages back to the originating server. Each return message contains the data ID and time information. A first return message (MSG1), sent immediately upon reception of the data, includes the start time ST0. One or more second messages (MSG2) sent conditionally after the first message indicate times elapsed between reception of the data and one or more user handling events effectively pre-specified in the timing script.