It would be useful to have a microbenchmark for the transport layer's send and receive performance, e.g., for SERVER-83304. The benchmark should set up an ASIO transport layer and send messages through it. It's worthwhile to test at least (1) a pure send situation in which the transport layer sends messages out to a server that doesn't respond, and (2) an echo situation in which the network layer sends messages out to a server that echoes them back. The former tests write performance exclusively and the latter tests read and write performance.