default socket receive buffer size, net.inet.tcp.recvspace (?)

[Ronald F. Guilmette]

I have just now found out that the kernel default value for
net.inet.tcp.recvspace, i.e. the default amount of receive
buffer space associated with a new socket is set to 56kB,
at least on the specific version of FreeBSD (4.7) that I'm
running.

Just curious:  why?

56kB seems like a somewhat odd number to pick for the default.

Why not 32kB or else 64kB?