Mills@UDEL.EDU (09/13/88)
Folks, In response to some UDP Domain Request packets directed to sri-nic.arpa, I am observing ICMP Source Quench messages from sri-nic.arpa in return. I assume sri-nic.arpa is full-up with domain requests and is asking us all to notch back a few decibels. Not many hosts are capable of such wonderful and intricate response and the implementors are to be congratulated. The lesson here may be that UDP namecallers should start thinking about responding to such things, not just TCP clients which ratchet down on window size. Dave
braden@VENERA.ISI.EDU (09/14/88)
Dave, To qoute from my favorite (draft) document, the Host Requirements RFC: "UDP is almost a null protocol; the only services it provides over IP are checksumming of data and multiplexing by port number. Therefore, an application program running over UDP must deal directly with a number of the end-to-end communication problems a connection-oriented protocol would have handled -- e.g., retransmission for reliable delivery, packetization and reassembly, flow control, congestion avoidance, etc." Yep, all those things! For "flow control", read "handle Source Quenches". Bob Braden
Mills@UDEL.EDU (09/14/88)
Bob, I know that you know that I know that. I don't know whether you know that everybody on this lists knows that we know that. Now everybody knows everything. Thanks for reminding us all to know that. The reference, of course. Dave
Mills@UDEL.EDU (09/14/88)
Bob, See, I planned all this so you could say that. Now, about specific engeneering principles. See the papers by Ramakrishnan, Jacobson and Mills in the recent SIGCOMM 88 Symposium and assorted RFCs and archives. No, I didn't plan all this so I could say that. Dave
ralphw@ius3.ius.cs.cmu.edu (Ralph Hyre) (09/29/88)
In article <8809132204.AA01771@braden.isi.edu> braden@VENERA.ISI.EDU writes: >Dave, > >To qoute from my favorite (draft) document, the Host Requirements RFC: > > > "UDP is almost a null protocol; the only services it provides over IP are > checksumming of data and multiplexing by port number. And am I still correct in assuming Sun doesn't even do half of those? (Or is UDP checksumming for NFS back in SunOS 4.0?) -- - Ralph W. Hyre, Jr. Internet: ralphw@ius3.cs.cmu.edu Phone:(412) CMU-BUGS Amateur Packet Radio: N3FGW@W2XO, or c/o W3VC, CMU Radio Club, Pittsburgh, PA "You can do what you want with my computer, but leave me alone!8-)"