The loss values refer to the percent of TCP (or SCTP) packets that were lost by our network connection emulated by DummyNet. The first value corresponds to lost TCP packets; the second value to lost SCTP packets.
The emulated path had a 56Kbps bandwidth and a 1080ms RTT, intended to represent a low bandwidth communication using satelites from a developing nation.
HTTP over TCP uses a single persistent pipelined TCP connection. HTTP over SCTP uses a single multistreamed SCTP association. When there is loss, the user experience greatly benefits from the combination of HTTP over SCTP and progressive jpeg images.