pppd, chat's HANGUP command, and callback

[Chris Nelson]

The chat man page gives an example of how to use HANGUP in a callback
environment:

ABORT `BUSY'
OK\r\n ATD1234567
\r\n \c
CONNECT \c
`Callback login:' call_back_ID
HANGUP OFF
ABORT "Bad Login"
`Callback Password:' Call_back_password
TIMEOUT 120
CONNECT \c
HANGUP ON
ABORT "NO CARRIER"
ogin:--BREAK--ogin: real_account
etc ...

but this seems to be for basic serial communication, not PPP. It seems
to me that if I use a chat script for pppd's connect option, pppd is
going to wait for that script to exit before doing any LCP, etc. so
this script/technique can't be used for callback with pppd. Am I right?

[James Carlson]

Post by Chris Nelson
but this seems to be for basic serial communication, not PPP.

I'm not sure what you mean by that, but the assumption made for that
example is that the initial dial that triggers the callback does not
need to negotiate PPP. You just call, chat some text, hang up, and
the peer calls you back. Some callback systems are configured to work
that way. Others are not.

Whether it works for you depends on exactly what sort of remote system
you're calling, and what it expects you to do.

Post by Chris Nelson
It seems
to me that if I use a chat script for pppd's connect option, pppd is
going to wait for that script to exit before doing any LCP, etc.

That's correct.

Post by Chris Nelson
so
this script/technique can't be used for callback with pppd. Am I right?

No. It depends on _how_ the peer does callback. There are many
different flavors and styles of callback. The name "callback" doesn't
identify any one standard or style of operation.

To make it work for you, you need to figure out what sort of callback
the peer expects to be doing.

(For what it's worth, that example is for the case where the peer
calls _you_ back. If you're trying to implement a system that calls
_others_ back, which is what I thought you were doing, then it's not
what you want.)