<s>
manage	O
network	O
connections	O
between	O
two	O
nodes	O
on	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
It	O
is	O
configured	O
using	O
command-line	B-Application
arguments	O
and	O
configuration	B-Protocol
files	I-Protocol
.	O
</s>
<s>
While	O
it	O
has	O
initially	O
been	O
used	O
to	O
manage	O
only	O
dial-up	O
access	O
,	O
it	O
is	O
also	O
used	O
to	O
manage	O
broadband	B-General_Concept
connections	O
such	O
as	O
DSL	O
,	O
if	O
Point-to-Point	B-Protocol
Protocol	I-Protocol
over	I-Protocol
Ethernet	I-Protocol
(	O
PPPoE	B-Protocol
)	O
or	O
Point-to-Point	B-Protocol
Protocol	I-Protocol
over	I-Protocol
ATM	I-Protocol
(	O
PPPoA	B-Protocol
)	O
is	O
used	O
.	O
</s>
<s>
The	O
role	O
of	O
pppd	B-Protocol
is	O
managing	O
PPP	O
session	O
establishment	O
and	O
session	O
termination	O
.	O
</s>
<s>
During	O
session	O
establishment	O
,	O
pppd	B-Protocol
has	O
the	O
role	O
of	O
:	O
</s>
<s>
When	O
PPPD	B-Protocol
sends	O
PPP	O
LCP	O
messages	O
,	O
these	O
messages	O
include	O
a	O
magic	O
number	O
.	O
</s>
<s>
Automatic	O
self	O
configuration	O
:	O
Using	O
Link	B-Protocol
Control	I-Protocol
Protocol	I-Protocol
it	O
has	O
to	O
negotiate	O
protocol	O
features	O
like	O
Address-and-Control-Field-Compression	O
(	O
ACFC	O
)	O
,	O
escaped	O
characters	O
,	O
and	O
the	O
compression	O
,	O
encryption	O
(	O
like	O
MPPE	B-Protocol
)	O
and	O
authentication	O
methods	O
to	O
use	O
.	O
</s>
<s>
Access	O
control	O
and	O
authentication	O
:	O
Using	O
protocols	O
like	O
Challenge-handshake	B-Protocol
authentication	I-Protocol
protocol	I-Protocol
(	O
CHAP	O
)	O
or	O
Password	B-Protocol
authentication	I-Protocol
protocol	I-Protocol
(	O
PAP	B-Protocol
)	O
it	O
has	O
to	O
provide	O
and	O
check	O
authentication	O
data	O
.	O
</s>
<s>
Layer	O
3	O
configuration	O
:	O
If	O
using	O
Internet	B-Protocol
Protocol	I-Protocol
Control	I-Protocol
Protocol	I-Protocol
(	O
IPCP	O
)	O
,	O
it	O
will	O
negotiate	O
or	O
determine	O
IP	B-Protocol
parameters	O
such	O
as	O
the	O
IP	B-Protocol
addresses	I-Protocol
,	O
the	O
maximum	B-Protocol
transmission	I-Protocol
unit	I-Protocol
,	O
and	O
name	B-Protocol
server	I-Protocol
addresses	O
.	O
</s>
<s>
Some	O
versions	O
may	O
also	O
support	O
Internetwork	B-Protocol
Packet	I-Protocol
Exchange	I-Protocol
Control	O
Protocol	O
(	O
IPXCP	O
)	O
and	O
AppleTalk	B-Application
Control	O
Protocol	O
(	O
ATCP	O
)	O
for	O
routing	O
IPX	B-Protocol
or	O
AppleTalk	B-Application
over	O
the	O
link	O
.	O
</s>
<s>
After	O
negotiation	O
is	O
complete	O
,	O
it	O
has	O
to	O
set	O
up	O
the	O
required	O
network	O
interfaces	O
and	O
routes	O
,	O
so	O
that	O
the	O
connection	O
is	O
run	O
by	O
the	O
kernel	B-Operating_System
.	O
</s>
<s>
pppd	B-Protocol
terminates	O
a	O
PPP	O
link	O
when	O
:	O
</s>
<s>
Some	O
newer	O
versions	O
of	O
pppd	B-Protocol
are	O
also	O
capable	O
of	O
handling	O
Dial-on-demand	B-Protocol
routing	I-Protocol
,	O
where	O
pppd	B-Protocol
sets	O
up	O
a	O
virtual	O
network	O
,	O
captures	O
the	O
packages	O
it	O
receives	O
and	O
establishes	O
a	O
PPP	B-Protocol
connection	I-Protocol
and	O
forwards	O
the	O
captured	O
and	O
not-yet	O
transmitted	O
packages	O
over	O
the	O
link	O
.	O
</s>
<s>
kppp	B-Protocol
–	O
A	O
kde	O
GUI	B-Application
frontend	B-General_Concept
for	O
pppd	B-Protocol
.	O
</s>
<s>
gnome-ppp	B-Protocol
–	O
A	O
gnome	O
GUI	B-Application
frontend	B-General_Concept
for	O
pppd	B-Protocol
.	O
</s>
<s>
pppconfig	B-Protocol
–	O
It	O
uses	O
the	O
standard	O
ppp	O
configuration	B-Protocol
files	I-Protocol
and	O
sets	O
ppp	O
up	O
so	O
that	O
the	O
standard	O
pon	O
and	O
poff	O
commands	O
(	O
to	O
connect	O
and	O
disconnect	O
)	O
and	O
plog	O
(	O
to	O
list	O
the	O
log	O
)	O
can	O
be	O
used	O
to	O
control	O
ppp	O
.	O
</s>
<s>
wvdial	B-Protocol
–	O
A	O
CLI	B-Application
tool	O
which	O
is	O
used	O
for	O
modem	B-Device
initialisation	I-Device
before	O
starting	O
pppd	B-Protocol
.	O
</s>
