mikeoro@hubcap.clemson.edu (Michael K O'Rourke) (10/11/89)
Does anyone know if a NBPConfirm in Appletalk generates network traffic and in which cases? For instance, i assume it would have to talk to a bridge to get to another zone, but what about confirming someone on my own zone? If they are on my zone will the names table in my machine be able to confirm them without causing network traffic? Michael O'Rourke
paul@taniwha.UUCP (Paul Campbell) (10/11/89)
In article <6724@hubcap.clemson.edu> mikeoro@hubcap.clemson.edu (Michael K O'Rourke) writes: >Does anyone know if a NBPConfirm in Appletalk generates network >traffic and in which cases? For instance, i assume it would have to >talk to a bridge to get to another zone, but what about confirming someone >on my own zone? If they are on my zone will the names table in my machine >be able to confirm them without causing network traffic? The names table in your machine is ONLY a list of the names registered by your machine. To do a confirm NBP does exactly the same thing as a lookup except that instead of doing a zone wide broadcast it directs the request packet(s) to the NBP socket on the machine that had registered the name. If the remote node is on another cable it these packets will go through the bridge etc etc Paul -- Paul Campbell UUCP: ..!mtxinu!taniwha!paul AppleLink: D3213 "Free Market": n. (colloq.) a primitive fertility goddess worshipped by an obscure cult in the late 20th C. It's chief priest 'Dow Jones' was eventually lynched by an enraged populace during an economic downturn (early 21st C).
rmh@apple.com (Rick Holzgrafe) (10/12/89)
In article <6724@hubcap.clemson.edu> mikeoro@hubcap.clemson.edu (Michael K O'Rourke) writes: > Does anyone know if a NBPConfirm in Appletalk generates network > traffic and in which cases? For instance, i assume it would have to > talk to a bridge to get to another zone, but what about confirming someone > on my own zone? If they are on my zone will the names table in my machine > be able to confirm them without causing network traffic? NBPConfirm sends a directed message (not a broadcast) to the address you're trying to confirm. That machine returns a message confirming, correcting (if the node is correct but the socket wrong), or denying the match. Unless the address you're confirming is in your own machine (unlikely but not impossible), there will be network traffic: the names table in your machine lists only the entities in your machine. NBP uses DDP to send its messages. DDP is "best effort", meaning that delivery is not guaranteed. If no response is received in time, NBP will re-send the confirmation request, hoping to finally "get through". NBP's patience between sends and the number of retries before giving up are specified by the caller. Note that in most cases, the match will be correct and the request will be quickly answered, so the network traffic will be minimal: one message, one response. But if the address is thoroughly bad (say, the target machine is turned off or disconnected) or if there's a lot of traffic or noise delaying or garbling transmission, then there'll be repeated attempts. See "Inside AppleTalk", Chapter 7, "Name Binding Protocol", for a full discussion. ========================================================================== Rick Holzgrafe | {sun,voder,nsc,mtxinu,dual}!apple!rmh Software Engineer | AppleLink HOLZGRAFE1 rmh@apple.com Apple Computer, Inc. | "All opinions expressed are mine, and do 20525 Mariani Ave. MS: 27-O | not necessarily represent those of my Cupertino, CA 95014 | employer, Apple Computer Inc."
Hueras@cup.portal.com (Jon F Hueras) (10/12/89)
NBPConfirm will always generate net traffic, unless the address being confirmed is on the same machine. What NBPConfirm will *not* do is generate any broadcast packets; the Lookup packets will always be directed to the address being confirmed.