Still initially uses TCP connect() (client) and TCP accept() (server) to establish a connection...
I wiresharked it...and captured the TCP traffic prior to the UDP xfers.... These subsequent write()'s (really send()'s) are UDP point to point...The destination address is remembered from the connect/accept sequence ....write() and/or send() have no destination IP address as an input parameter.... UDP sendto(), however, does require a destination which can be a unique IP address or broadcast.... I built iperf within cygwin on a Windows 7 machine. I modified iperf and found that UDP sendto's are approx. 50% slower than UDP send's..... -----Original Message----- From: iperf-users-requ...@lists.sourceforge.net [mailto:iperf-users-requ...@lists.sourceforge.net] Sent: Thursday, July 21, 2016 3:38 PM To: iperf-users@lists.sourceforge.net Subject: Iperf-users Digest, Vol 69, Issue 4 Send Iperf-users mailing list submissions to iperf-users@lists.sourceforge.net To subscribe or unsubscribe via the World Wide Web, visit https://lists.sourceforge.net/lists/listinfo/iperf-users or, via email, send a message with subject or body 'help' to iperf-users-requ...@lists.sourceforge.net You can reach the person managing the list at iperf-users-ow...@lists.sourceforge.net When replying, please edit your Subject line so it is more specific than "Re: Contents of Iperf-users digest..." Today's Topics: 1. Re: I see UDP recvfrom() in iperf, but no sendto() .... calls write() (Bob McMahon) 2. Re: (no subject) (Tomer Pollak) 3. Re: (no subject) (Bob McMahon) ---------------------------------------------------------------------- Message: 1 Date: Wed, 20 Jul 2016 14:27:14 -0700 From: Bob McMahon <bob.mcma...@broadcom.com> Subject: Re: [Iperf-users] I see UDP recvfrom() in iperf, but no sendto() .... calls write() To: "Hoshall, Paul" <hos...@textronsystems.com> Cc: "iperf-users@lists.sourceforge.net" <iperf-users@lists.sourceforge.net> Message-ID: <CAHb6LvqN2V2RaNgDbz27NLtJ8K5tZL59n=iN=hsaj2gzrmm...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Which iperf version, i.e. output of iperf -v? write() can be used with UDP after a socket connect(). The socket connect occurs in Client::Connect() method for iperf 2+ UDP sockets support both connect() and bind() even though UDP connectionless. A connected UDP socket isn't connected in the TCP sense, but more in the file descriptor sense. Bob *************************** ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev _______________________________________________ Iperf-users mailing list Iperf-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/iperf-users
