Path: utzoo!attcan!uunet!lll-winken!ames!amdahl!rtech!wrs!hwajin From: hwajin@wrs.wrs.com (Hwajin Bae) Newsgroups: comp.protocols.tcp-ip Subject: Re: connect(2) timeout Message-ID: <748@wrs.wrs.com> Date: 17 Aug 89 18:57:12 GMT References: <24692@iuvax.cs.indiana.edu> <747@wrs.wrs.com> Reply-To: hwajin@wrs.wrs.com (Hwajin Bae) Organization: Wind River Systems, Emeryville, CA Lines: 17 Of course, the 10 minute keep-alive timeout scenario is only valid if you don't get anything from the remote system after sending the initial SYN packet. If you get something back from the remote system that cancels the keep-alive timeout, TCP will get into a bit more complicated retransmission stage -- and subsequently will take longer for connect() to actually time out. TCP will keep on retransmitting the SYN packet until it receives ACK/SYN for it. TCP retransmission back-off is based on the binary exponential algorithm (1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64) and the retransmission time will vary from 1 to 64 seconds and happend upto 12 times. -- Hwajin Bae Wind River Systems 1350 Ocean Ave Emeryville, CA 94608