Date: Fri, 26 Apr 2002 09:31:43 -0700 From: mkenney@igscb.jpl.nasa.gov Message-Id: Subject: [IGSMAIL-3847]: Message for igsmail Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 26 Apr 09:31:43 PDT 2002 Message Number 3847 ****************************************************************************** Author: Ron Muellerschoen, Ken MacLeod, Mark Caissy There was substantial discussion at the recent IGS workshop in Ottawa on real-time flow of GPS data. Specific concerns were the underlaying protocol, TCP vs UDP, and whether organizations will be able to open there firewall to a specific port number. We call on organizations to participate in a simulated data flow test, using both protocols for the week of April 29 to May 3rd. We have designated a target portnumber for both protocols as 3738. (Currently the IANA registered port numbers in the range of 3738 to 3801 are unassigned. ) We ask organizations interested in participation to run clients at their sites and provide back to us input on access problems, success rates, and latency issues, with both protocols. We would prefer to see clients run simultaneously, and looking at different servers on various IP providers. The more clients hitting these severs, with the different protocols, the more information we can quickly obtain on how to build the final iGPSDR system. Additional information to obtain and run the clients and can be found at: ftp://sideshow.jpl.nasa.gov/pub/rjm/client_igs/README Please experiment with the different servers, and with a different number of site requests. Shortly the igs central bureau will establish an rtwg mailing list. Once this has been established, please respond to rtwg@igscb.jpl.nasa.gov with your findings. We would be interested in hearing about data latencies as listed in the log files, the success rates as listed in the summary files, and the number of dropped connections. We are particularly interested in hearing about the differences you see between a TCP connection and a UDP feed. thank you for your efforts, and best regards, ron,ken,mark