My OpenBSD 5.2 /etc/ppp/ppp.conf file used for connecting to my copper.net dialup account. This is executed via the "ppp -auto copper" command as user root.

pf.conf

#       $OpenBSD: pf.conf,v 1.50 2011/04/28 00:19:42 mikeb Exp $
#
# See pf.conf(5) for syntax and examples.
# Remember to set net.inet.ip.forwarding=1 and/or net.inet6.ip6.forwarding=1
# in /etc/sysctl.conf if packets are to be forwarded between interfaces.

set skip on lo

# filter rules and anchor for ftp-proxy(8)
#anchor "ftp-proxy/*"
#pass in quick inet proto tcp to port ftp divert-to 127.0.0.1 port 8021

# anchor for relayd(8)
#anchor "relayd/*"

pass            # to establish keep-state

# rules for spamd(8)
#table <spamd-white> persist
#table <nospamd> persist file "/etc/mail/nospamd"
#pass in on egress proto tcp from any to any port smtp \
#    rdr-to 127.0.0.1 port spamd
#pass in on egress proto tcp from <nospamd> to any port smtp
#pass in log on egress proto tcp from <spamd-white> to any port smtp
#pass out log on egress proto tcp to any port smtp


#block in quick from urpf-failed to any # use with care

# By default, do not permit remote connections to X11
block in on ! lo0 proto tcp to port 6000:6010

# Note that my network has bge0 as its ethernet card, and tun0 as its PPP interface
pass out on tun0 from bge0:network to any nat-to tun0

ppp.conf

#################################################################
#
#       PPP  Sample Configuration File
#
#         Originally written by Toshiharu OHNO
#
# $OpenBSD: ppp.conf.sample,v 1.24 2006/07/30 18:02:01 david Exp $
#
#################################################################

# This file is separated into sections.  Each section is named with
# a label starting in column 0 and followed directly by a ``:''.  The
# section continues until the next section.  Blank lines and lines
# beginning with ``#'' are ignored.
#
# Lines beginning with "!include" will ``include'' another file.  You
# may want to ``!include ~/.ppp.conf'' for backwards compatibility.
#

# Default setup. Always executed when PPP is invoked.
#  This section is *not* loaded by the ``load'' or ``dial'' commands.
#
#  This is the best place to specify your modem device, its DTR rate,
#  and any logging specification.  Logging specs should be done first
#  so that subsequent commands are logged.
#
default:
 set log Phase Chat LCP IPCP CCP tun command
 set device /dev/cua00
 set speed 115200
 set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \"\" AT OK-AT-OK ATE1Q0 OK \\dATDT\\T TIMEOUT 40 CONNECT"

# Client side PPP
#
#  Although the PPP protocol is a peer to peer protocol, we normally
#  consider the side that makes the connection as the client and the
#  side that receives the connection as the server.  Authentication
#  is required by the server either using a unix-style login procedure
#  or by demanding PAP or CHAP authentication from the client.
#

# An on demand example where we have dynamic IP addresses:
#  If the peer assigns us an arbitrary IP (most ISPs do this) and we
#  can't predict what their IP will be either, take a wild guess at
#  some IPs that you can't currently route to.
#
#  The /0 bit in "set ifaddr" says that we insist on 0 bits of the
#  specified IP actually being correct, therefore, the other side can assign
#  any IP numbers.
#
#  The fourth arg to "set ifaddr" makes us send "0.0.0.0" as our requested
#  IP number, forcing the peer to make the decision.
#
#  This entry also works with static IP numbers or when not in -auto mode.
#  The ``add'' line adds a `sticky' default route that will be updated if
#  and when any of the IP numbers are changed in IPCP negotiations.
#  The "set ifaddr" is required in -auto mode.
#
#  Finally, the ``enable dns'' bit tells ppp to ask the peer for the
#  nameserver addresses that should be used.  This isn't always supported
#  by the other side, but if it is, /etc/resolv.conf will automatically be
#  updated.
#
copper:
 set authname ******@copper.net
 set authkey ******
 set phone 6133326251
 #set login "ABORT NO\\sCARRIER TIMEOUT 5 rname:--rname: ppp word: ppp"
 set timeout 120
 add default HISADDR
 enable dns