6. Changes between RFC 2001 and RFC 2581

[RFC2001] was extensively rewritten editorially and it is not feasible to itemize the list of changes between [RFC2001] and [RFC2581]. The intention of [RFC2581] was to not change any of the recommendations given in [RFC2001], but to further clarify cases that were not discussed in detail in [RFC2001]. Specifically, [RFC2581] suggested what TCP connections should do after a relatively long idle period, as well as specified and clarified some of the issues

pertaining to TCP ACK generation. Finally, the allowable upper bound for the initial congestion window was raised from one to two segments.