In UNIX SVR4, the plumbing between STREAMS drivers is maintained by either ordinary or persistent links. A persistent link is not dependent on its controlling stream remaining open. A user process plumbs persistent links with the I_PLINK and I_PUNLINK stream head IOCTL commands.
STREAMS does not support persistent links. When the last stream to the topmost STREAMS driver is closed, the plumbing underneath that driver is dismantled. Thus, a persistent plumbing daemon is required to maintain a transport stack under Windows NT.
STREAMS on Windows NTdoes not provide an autopush facility.