M2M
Cellular
Gateway
Index
skipping
is
used
to
reserve
slots
for
new
function
insertion,
when
required.
271
Scenario
Application
Timing
Above
diagram
illustrates
the
security
gateway
at
headquarters
playing
the
L2TP
VPN
server
role.
The
L2TP
tunnel
is
established
by
starting
from
L2TP
client,
the
Security
Gateway
2
in
Network
‐
B
or
the
mobile
device,
like
notebook.
All
client
hosts
behind
the
Security
Gateway
2
or
the
mobile
device
can
access
the
resources
in
the
Intranet
of
Network
‐
A
at
headquarters
via
this
established
L2TP
tunnel.
Usually,
these
hosts
at
L2TP
client
peer
access
the
Internet
directly
via
the
WAN
interface
of
Security
Gateway
2.
Only
the
packets
whose
destination
is
in
the
dedicated
subnet
to
Network
‐
A
will
be
transferred
via
the
L2TP
tunnel.
Scenario
Description
L2TP
Tunneling
is
a
Client
and
Server
based
tunneling
technology.
The
L2TP
Server
must
have
a
Static
IP
or
a
FQDN,
and
maintain
a
Client
list
(account
/
password);
The
Client
may
be
a
mobile
user
or
mobile
site,
and
requesting
the
L2TP
tunnel
connection
with
its
account
/
password.
L2TP
protocol
is
used
for
establishing
an
L2TP
VPN
tunnel.
Parameter
Setup
Example
For
Network
‐
A
at
HQ
Following
3
tables
list
the
parameter
configuration
for
above
example
diagram
of
L2TP
VPN
server
in
Network
‐
A.
Use
default
value
for
those
parameters
that
are
not
mentioned
in
these
tables.
Configuration
Path
[L2TP]
‐
[Configuration]
L2TP
■
Enable
Client/Server
Server
Configuration
Path
[L2TP]
‐
[L2TP
Server
Configuration]
L2TP
Server
■
Enable
L2TP
over
IPSec
■
Enable
Preshare
Key
12345678
Server
Virtual
IP
192.168.101.253
IP
Pool
Starting
Address
10
(that
means
192.168.101.10)
IP
Pool
Ending
Address
50
(that
means
192.168.101.50)
Authentication
Protocol
MS
‐
CHAP
MPPE
Encryption
■
Enable
128
bits
Service
Port
1701
Configuration
Path
[L2TP]
‐
[User
Account
Configuration]
ID
1
2
User
Name
User
‐
1
User
‐
2
Password
1234
4321
Account
■
Enable
■
Enable
Scenario
Operation
Procedure
