bschmidt@bnr.ca (Ben Schmidt (BNR)) (01/30/91)
In article <0B010004.mj9ay5@outpost.UUCP> peirce@outpost.UUCP (Michael Peirce) writes: > In article <1991Jan27.144523.20674@phri.nyu.edu>, roy@alanine.phri.nyu.edu (Roy Smith) writes: > > > > Second, would it be a Bad Thing for the network? I could see how it > > might result in a flood of synchronized responses clogging the wire > > momentarily, ... > > You need to be very careful how you implement this. I know there > are programs out there at do this (generally) already and I've heard > complaints about how they adversely affect some networks. > > Many schemes that work for a small network fall apart for larger nets > - think about doing NBP lookups on a network with 50 different zones > or more (they're are many of these size networks out there) and waiting > for that on every launch! Amen. Everytime someone fires up ACIUS 4D on our AppleTalk internet, it not only issues broadcasts on the local ATalk net to which the Mac is attached, but also broadcast requests to every other ATalk net on our internet. Thats 230+ nets! In our case, say someone in Richardson, Tx fires up 4D, ATalk broadcast requests are issued for every net in Richardson, then over leased lines to every ATalk net in Atlanta, RTP, Ottawa, Montreal, then over a *very* expensive TAT8 link to ATalk nets in the U.K.! I've complained to ACIUS about this. They looked at me condescendingly over their glasses and said, "Not to worry. We do these broadcasts as a background task so it doesn't impact the user!" Natch, if you buy a bulk order you can no doubt negotiate this obnoxious network-hostile copy-protection out, but ACIUS 4D was not bought here in a bulk order. It was bought in 1's and 2's by umpteen different groups and users. I earnestly hope other software developers don't look to ACIUS' technique as a model. (PS. Michael Pierce, one of the previous posters to this thread, is a developer who appears to have given limiting broadcasts some serious thought. His Public Folder RDEV, unlike Apple's own AppleShare and LaserWriter drivers, does *not* mindlessly generate NBP lookups forever. Instead, Public Folder generates some initial traffic to locate other Public Folder users in the selected zone, and then *stops*. People don't leave the Chooser DA open you say? Yah well tell that to the secretary who can't get into an AppleShare fileserver at its 50-session limit, and who keeps the Chooser DA open all morning so she can keep trying between calls and filing. Now multiply by many people and sprinkle in users of network-hostile protection schemes like ACIUS'. Yup, I wonder how AppleTalk earned it's reputation of being an overly chatty (read broadcasty) protocol?) Ben Schmidt Bell-Northern Research, Ltd. Ph: (613) 763-3906 Information P.O. Box 3511, Station C FAX:(613) 763-3283 Technology Ottawa Canada K1Y 4H7 bschmidt@bnr.ca