Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!rpi!image.soe.clarkson.edu!news From: nelson@sun.soe.clarkson.edu (Russ Nelson) Newsgroups: comp.protocols.tcp-ip.ibmpc Subject: Re: ODI? Message-ID: Date: 15 Aug 90 02:38:12 GMT References: <11303@j.cc.purdue.edu> <1990Aug13.234051.19998@portia.Stanford.EDU> <2397@east.East.Sun.COM> Sender: news@sun.soe.clarkson.edu Reply-To: nelson@clutx.clarkson.edu (aka NELSON@CLUTX.BITNET) Organization: Clarkson University, Potsdam NY Lines: 32 In-reply-to: geoff@hinode.East.Sun.COM's message of 14 Aug 90 15:36:40 GMT In article <2397@east.East.Sun.COM> geoff@hinode.East.Sun.COM (Geoff Arnold @ Sun BOS - R.H. coast near the top) writes: Why not adopt PD instead? Because in principle I think that NDIS does demultiplexing "right" and ODLI and PD do it "wrong". If *that*'s your only objection to the PD, then we can bash jbvb@ftp.com over the head until he changes the spec to allow multiple drivers to be upcalled with the same packet. Then your application can just ask for all packets. I prefer a procedural model, where a frame (or at least some part of the frame) is offered to each protocol stack which can accept or reject it, to one where the driver does the filtering based upon some template. If the template mechanism is rich enough to do everything I could imagine wanting to, it is bound to be slower and larger than any single protocol-specific recognition procedure. But the procedural model bogs down in the details. How do you write a procedural model that works equally well on I/O and memory-mapped cards? The PD gets around this by letting you examine at most 8 bytes of the packet, and only 4 of these make sense for Ethernet. Perhaps the reason you've seen NDIS drivers that are big and slow is because the NDIS spec is big (and requires slowness)? Perhaps because NDIS comes from that firm whose products are big and slow (bash, bash)? It's no coincidence that the packet drivers are shipped to assemble with tasm, and link with tlink. -- --russ (nelson@clutx [.bitnet | .clarkson.edu]) Russ.Nelson@$315.268.6667 We won the cold war. The Russians spent trillions defending their stuff, then they found that they didn't have any stuff. Will we avoid the same trap?