Fixing Two BSD TCP Bugs
Mark C. Allman · NASA Technical Reports Server (NASA) · 1997
This note outlines two bugs found in the BSD 4.4 Lite TCP implementation, as well as the implications of these bugs and possible ways to correct them. The first problem encountered in this particular TCP implementation is the use of a 2 segment initial congestion window, rather than the standard 1 segment initial window. The second problem is that the receiver delays ACKs in violation of the delayed ACK rules. 1 Introduction This report discusses two bugs found in the Berkeley Software Distribution release 4.4 Lite implementation of the Transmission Control Protocol (TCP) [Pos81]. NetBSD's implementation of TCP is derived from BSD 4.4 Lite and therefore inherited these bugs 1 . In this paper, "TCP" will refer to standard TCP [Pos81] [Bra89] [Ste97], while "NTCP" will refer to the NetBSD implementation of TCP. The following two sections include an outline of the particular problem and the implications the problem. Next, each section will examine the details that cause the problem, an...