No buffer space available

Hi, All!
In my cache.log I see a lot of messages like these:
1999/08/28 18:59:10| comm_accept: FD 6: (105) No buffer space available
1999/08/28 18:59:10| httpAccept: FD 6: accept failure: (105) No buffer
space available

Could anyone explain, what does it mean?

                                          Petrovich (Kolya)
Received on Mon Aug 30 1999 - 02:37:20 MDT