Chance:
> This brings up a "connectivity" issue - if not enough sites carry
> the group, doesn't internet come up with the equivalent of a "you can't
> get there from here" error when forwarding articles?
urm. quick lecture on Usenet operation. (note: Usenet is not
Internet.)
articles on Usenet get sent by the "chain letter" method: site P gives
the article to all its neighbors (Q, R, S, T), who each give the
article to _their_ neighbors, etc.
if a transfer fails for some reason, it usually gets retried.
sometimes it won't, but this is usually harmless because there's often
more than one path between any two sites. if the article doesn't get
there one way, it can get there some other way. this is what the
"Path:" header shows you: the route the message took to reach you.
that's the ideal situation. the complication is: if alt.tv.swatkats
isn't carried by a site, then when the site receives an article for
it, propagation stops there. maybe. many sites will continue
propagating the article anyway. it depends on the site's software and
configuration.
there's no feedback mechanism; no way for a poster to find out how far
their posting is propagated. and anyway, you don't really want to
receive a "got it!" message from thousands of locations, do you?
next complication: to create a newsgroup, you post a "newgroup"
control message, which propagates like a normal article. every site
that receives that message then adds the group locally.
except this only happens if the site is configured to automatically
create the group. since anyone can send a "newgroup" message (and
since by now most everyone has), most news sites will not add new
groups automatically, especially in alt.
instead, the site's news admin gets mail saying, "hi! someone
reallyreally wants you to add a new group", and if they feel like it,
they type in the command to add the group to their site. since humans
tend to be sluggish creatures, it can be a day or so before this
happens. or it could be never.
and also, the "newgroup" message can get lost like any other article,
so you may have to send several of them to make sure it reaches every
part of the network that it was supposed to reach.
--
Received on Sat Jul 15 1995 - 04:51:39 PDT