[comp.protocols.tcp-ip] Multiple versions of TALK?

towfiq@interlan.Interlan.COM (Mark Towfigh) (07/03/90)

Note the followup group is comp.protocols.tcp-ip, as I don't read
comp.unix.questions.

In article <1990Jul3.040115.12000@hayes.fai.alaska.edu>
wisner@hayes.fai.alaska.edu (Bill Wisner) writes:

   There is no RFC for talk.

I know this is true -- it's a problem because there are incompatible
versions of TALK out there.  Specifically, it seems there was a change
between the 4.2BSD talk/talkd and the one in 4.3BSD. I have a few
questions: does the current TALK daemon support both the old and new
versions?  And what about the client?  As far as I can make out, the
new talkd can tell the difference between the two protocols, and when
a remote user requests a connection, the local TALK daemon figures out
whether they are TALKing 4.2-style or 4.3-style, and then tells the
local user to run one of two programs, either /usr/ucb/talk or
/usr/old/talk.

All this aside, I have never seen this work with the 4.2 TALK, only
the 4.3 flavor.  Is there anyone out there running a system which can
talk in both styles, and deal with incoming and outgoing TALK
requests?
--
Mark Towfigh, Racal InterLan, Inc.                 towfiq@interlan.Interlan.COM
W: (508) 263-9929 H: (617) 488-2818                       uunet!interlan!towfiq

  "The Earth is but One Country, and Mankind its Citizens" -- Baha'u'llah

jik@athena.mit.edu (Jonathan I. Kamens) (07/04/90)

In article <TOWFIQ.90Jul3095602@interlan.Interlan.COM>,
towfiq@interlan.Interlan.COM (Mark Towfigh) writes:
|> I know this is true -- it's a problem because there are incompatible
|> versions of TALK out there.  Specifically, it seems there was a change
|> between the 4.2BSD talk/talkd and the one in 4.3BSD. I have a few
|> questions: does the current TALK daemon support both the old and new
|> versions?

  No.  You have to run two different versions of talkd, one on the port
reserved for the old talk protocol, and one on the port reserved for the
new talk protocol.  On our system, old talk is 517 (with the service
name "talk"), and new talk is 518 (with the service name "ntalk").

  If you don't have the right daemons running on the right ports, then
talk clients are going to have trouble conversing with your machine.

|> And what about the client?

  Nope, the old talk client knows how to talk only to the old talk port,
and the new talk client knows how to talk only to the new talk port. 
Or, at least, that's how things *should* work, but alas, we live in an
imperfect world....

|> As far as I can make out, the
|> new talkd can tell the difference between the two protocols, and when
|> a remote user requests a connection, the local TALK daemon figures out
|> whether they are TALKing 4.2-style or 4.3-style, and then tells the
|> local user to run one of two programs, either /usr/ucb/talk or
|> /usr/old/talk.

  No, this isn't how it works, or at least not how it appears to be set
up in 4.3BSD.  There are two different talkd programs (/etc/talkd and
/etc/ntalkd is what we've got them named, but I don't know how universal
that is).  The hard-coded client name in the old talk daemon is
/usr/ucb/talk.old or /usr/old/talk, and the hard-coded client name in
the new talk daemon is /usr/ucb/talk.  The new talk daemon and the old
talk daemon don't know about each other, and don't know about each
other's protocols.

Jonathan Kamens			              USnail:
MIT Project Athena				11 Ashford Terrace
jik@Athena.MIT.EDU				Allston, MA  02134
Office: 617-253-8495			      Home: 617-782-0710

brian@ucsd.Edu (Brian Kantor) (07/04/90)

There are two talk programs using two different protocols; the older
one still found on Suns and such is architecture and compiler dependent
and often won't work across heterogeneous hosts.  The newer talk will
work in such an environment but not everyone has it.  Since it's part
of the great Berkeley giveaway, you should get the newer talk and
install it.  It can coexist with the older talk because it lives on a
different port and has a different name.  4.3-Tahoe-BSD comes with both.
	- Brian

emv@math.lsa.umich.edu (Edward Vielmetti) (07/04/90)

a word as to actual usage of these two talks across the nsfnet backbone -- in the
months where port-by-port statistics are kept on nis.nsf.net (the *PORTS files)
talk+ntalk (517+518) is in about the 0.2% - 0.3% range, with the amounts varying
quite substantially and talk generally having more traffic than ntalk.  Must be
lots of suns, I guess.  

--Ed

Edward Vielmetti, U of Michigan math dept <emv@math.lsa.umich.edu>
comp.archives moderator

QOP@CORNELLA.BITNET (Caleb Strockbine) (07/05/90)

Steve-

I've got one version of talk running already... the daemon doesn't
run all the time (some daemon, eh?) but instead it's called by the
"master internet daemon" called inetd, which also calls a bunch of
the other communication daemons, but only when they're necessary. As
far as I know, we don't have ntalk, which seems to be the newer version
of talk, so maybe I'll look for that so we'll be able to talk to
anyone.

I wondered about that message about Mac/Unix connectivity, and whether
that wasn't the same thing we're trying to do. Maybe I'm beginning to
get the hang of this!

-Caleb.

imp@dancer.Solbourne.COM (Warner Losh) (07/05/90)

In article <EMV.90Jul3171720@urania.math.lsa.umich.edu> emv@math.lsa.umich.edu (Edward Vielmetti) writes:
>a word as to actual usage of these two talks across the nsfnet
>backbone -- in the months where port-by-port statistics are kept on
>nis.nsf.net (the *PORTS files) talk+ntalk (517+518) is in about the
>0.2% - 0.3% range, with the amounts varying quite substantially and
>talk generally having more traffic than ntalk.  Must be 
>lots of suns, I guess.  

FYI, the talk/ntalk protocol is just used for connection setup.  Once
people agree to talk, both protocols contain "pointers" to TCP ports
to carry the actual conversation on.  In fact, these "pointers" are
what caused the inability for "talk" to function in a heterogeneous
environment (without all kinds of heuristic gyrations, that is).

-- 
Warner Losh			imp@Solbourne.COM