On Tue, 6 May 1997 07:00:15 -0400 
 "Don Ray" <dray@servecom.picker.com> wrote:

 > because I'm looking for a ppp daemon that will do demand-dialing for a
 > couple hundred ip-addresses/dialouts without running a damon for each
 > dial-out. The NetBSD ppp does demand-dialing, but you have to run a daemon
 > for each one. This works fine if you only have a few dial-ups but I'll have
 > hundreds.  I'm looking for something like Linux's diald. From what I've
 > read, it appears iij-ppp will do what I need but I won't know until I get
 > it up and test it.

...hmm, how does iijppp do it?  By forking, I guess?  It's got to listen
on multiple "tun" devices ... I suppose it could multiplex them itself,
but when you have a LARGE number of descriptors, that could get pretty
hairy...

Anyhow, if you're going to be using that many, how can it possibly perform
reasonably?  Doesn't iijppp read the data from serial, then use the "tun"
device to pass the data back into the kernel?  That implies that every
packet is going to be copied out to userspace, then copied back into the
kernel.  For hundreds of connections, the copying overhead will kill you!

...besides, with demand-paged executables and shared libraries, running
multiple copies of pppd probably isn't all that bad... the text of all
copies of pppd and libraries will be shared...

Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
NAS: M/S 258-6                                          Work: 415.604.0935
Moffett Field, CA 94035                                Pager: 415.428.6939