Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!decvax!decwrl!ucbvax!LOKI.BBN.COM!craig From: craig@LOKI.BBN.COM.UUCP Newsgroups: mod.protocols.tcp-ip Subject: Analyzing Acknowledgement Strategies Message-ID: <8612241633.AA10001@ucbvax.Berkeley.EDU> Date: Wed, 24-Dec-86 11:33:59 EST Article-I.D.: ucbvax.8612241633.AA10001 Posted: Wed Dec 24 11:33:59 1986 Date-Received: Wed, 24-Dec-86 20:39:43 EST Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 24 Approved: tcp-ip@sri-nic.arpa Has anyone done any work analyzing acknowledgement strategies on a theoretical level? It seems to me there is an inherent conflict in choosing acknowledgement strategies. To reduce unnecessary retransmissions of data packets, one wants to make sure data packets get acknowledged. But the best (only?) way to make sure acknowledgements get through is to send more of them. It is easy to identify bad strategies. A system which sends twenty acknowledgements for every packet is a bad strategy because the number of unneeded acknowledgements sent will clog a network more than the reduction in unnecessary retransmissions (because an ack was lost) could ever reduce network traffic. Similarly, a system which acknowledges too little abuses the network because too many data packets get unnecessarily retransmitted -- up to a point acknowledging more often will reduce the *total* number of packets sent. (At least that's what testing with RDP shows). The problem is identifying where these tradeoffs balance out -- where the range of optimal solutions lies (if anywhere) in this space. Has anyone ever looked at this issue? Craig