Update: It turns out I was slightly mistaken below when I implied there's no way to tune window-scaling per-socket; ref tcp(7) (at least on my Linux and the link here) that indicates with kernel-level window-scaling enabled, tuning of the socket buffers do in fact impact the window scaling. As always, refer to your specific distro's system pages for particulars. /Update

No, at least not that I've seen; this said, maybe some exotic distro does support these specific features on a per-socket basis rather than per-host. I was focusing on the "etc" part of OP's inquiry, suggesting an interest in tuning any socket-level options.

The answer to such questions can only be found the OS-level manpages and resources for the target platform; these frequently reference additional resources, frequently noting the system-level knobs to which you referenced earlier.

Perl's only as functional as the underlying OS, so sometimes use of advanced features in Perl require getting a bit "dirty" by digging into the system or C APIs.