M2M
Cellular
Gateway
Index
skipping
is
used
to
reserve
slots
for
new
function
insertion,
when
required.
268
5.5.7
L2TP
Layer
2
Tunneling
Protocol
(L2TP)
is
a
tunneling
protocol
used
to
support
virtual
private
networks
(VPNs)
or
as
part
of
the
delivery
of
services
by
ISPs.
It
does
not
provide
any
encryption
or
confidentiality
by
itself.
Rather,
it
relies
on
an
encryption
protocol
that
it
passes
within
the
tunnel
to
provide
privacy.
This
Gateway
can
behave
as
a
L2TP
server
and
a
L2TP
client
both
at
the
same
time.
Deploy
a
security
gateway
for
local
office
and
establish
a
virtual
private
network
with
the
remote
gateway
of
another
office
by
using
L2TP
tunneling.
So,
all
client
hosts
behind
local
security
gateway
can
make
data
communication
with
others
behind
remote
gateway.
Or
when
you
are
a
mobile
user
with
your
notebook
or
carrying
along
a
security
gateway
and
you
want
to
access
the
servers
and
database
in
company
headquarters
(HQ).
Moreover,
the
security
gateway
in
HQ
supports
the
L2TP
VPN
server
function.
So
you
can
dial
in
the
HQ
gateway
and
access
the
HQ
resources
by
establishing
an
L2TP
VPN
tunnel.
It
is
a
virtual
private
network
between
your
device
and
HQ
gateway
for
your
resource
accessing.
In
"L2TP"
page,
there
is
the
"Configuration"
window
to
enable
the
L2TP
VPN
function.
The
security
gateway
can
either
take
a
"L2TP
Server"
role
or
"L2TP
Client"
role
or
they
both.
Define
and
choose
either
one
role
for
your
router
in
the
"Configuration"
window
and
configure
all
required
parameters
