Exchanging of videoconference data between a first endpoint and a second endpoint via a network includes receiving, at the first endpoint, statistical data relating to transmission of first videoconference data. In particular, the first videoconference data is data that is transmitted previously from the first endpoint to the second endpoint via the network, and the statistical data relates to network performance characteristics during transmission of the first videoconference data. An approximately optimized data transmission rate for the network performance characteristics is determined, based on the statistical data. The output bit rate of a video encoder associated with the first endpoint is adjusted, such that second videoconference data, relating to the same videoconference at a time that is later than the first videoconference data, is encoded to provide output data at an adjusted output bit rate for being transmitted via the network at approximately the optimized data transmission rate.