Installing and Administering PPP

80 Chapter 4
Common pppd Options
Unique PPP Implementations
reconnect using the next entry in Systems, or, if no additional entries
exist, pppd wraps around to the first entry in the file which is the
dedicated connection.
Constantly-Open Telephone Calls
Some PPP connections are always up. The system does not use pppd’s
on-demand dialing to reestablish a link for new traffic. This is not the
same as using a dedicated line, because modems on constantly open
connections must be dialed, or a login negotiated, before PPP frames can
be exchanged. In the “constantly up” situation, use the “up” argument
on pppd’s command line. The argument “up” instructs pppd to make
every effort to keep the connection up. For example, when the connection
goes down, pppd immediately redials the modem, rather than waiting for
traffic demand. Do not use the up and idle arguments together.