Path: utzoo!attcan!uunet!lll-winken!uwm.edu!cs.utexas.edu!husc6!paperboy!osf.org!santi From: santi@osf.org (Michael Santifaller) Newsgroups: comp.protocols.tcp-ip Subject: Re: Reliable Broadcasts? (was Re: Reliable Datagram ??? Protocols) Message-ID: <15403@paperboy.OSF.ORG> Date: 25 Oct 90 13:21:25 GMT References: <9010221418.AA03839@ftp.com> Sender: news@OSF.ORG Reply-To: santi@osf.org (Michael Santifaller) Organization: Open Software Foundation Lines: 32 In article , gnb@bby.oz.au (Gregory N. Bond) writes: > Well, on a similar note.... > > I understand James' and Jon's arguments. Reliable datagrams are best > implemented with TCP and a "write(len); write(data);" layer. I am > looking for something a little different. > > Consider a net with a server and many (say, 100) workstations, and a > data feed that goes to each workstation. At the moment, I have to > open 100 TCP streams, and so each packet of data generates 200 TCP > packets, all more-or-less identical. What would be nice would be to > broadcast the packet to the local net, and have the clients request > missed packets, thus implementing a sort of reliable broadcast. > I would use broadcast RPC do this. SunRPC for example allows broadcasts to several servers simultaneously, you can get a reply from each and compare this with your list of recepients. I have no idea what the overhead for such a algorithm is, since the broadcasts are done through the portmapper on each system. Give it a try and make some measurements to find out its feasibility. RPC programming is easy to do. Michael Santifaller ------------------------------------------------------------------------ --------Michael Santifaller, PentaCom GmbH (Yes, OSF uses NCS, but then -- I'm not an OSF employee) --------------------------------------------------------------------------------