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VoIP subscriber gateways
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–
Service-Name
– Service-Name tag value in PADI message for PPPoE connection
initialization (this field is optional: set the parameter if it is required by provider);
–
MTU size
– maximum block size for data transmitted via the network (1492 is
recommended);
–
PPTP
–
operation mode when the Internet access is established via a special channel—a tunnel—
using VPN;
–
L2TP
– protocol for VPN realization.
PPTP and L2TP allow establishing secure communication link over the Internet between
the remote user's computer and organization's private network. PPTP and L2TP are based on
Point-to-Point Protocol (PPP) and act as its extension. First, the OSI model higher level data is
encapsulated into PPP, and then into PPRP or L2TP for tunnel transmission via public data
networks. PPTP and L2TP functionality differs. L2TP may be used not only in IP networks,
service messages for tunnel creation and data transfer use the same format and protocols.
PPTP may be used only in IP networks, it requires a dedicated TCP connection for tunnel
creation and usage. L2TP over IPSec
1
allows for the higher security level compared to PPTP
and guarantees the higher level of protection for business-critical data.
Due to its characteristics, L2TP is an attractive protocol for building virtual networks.
During the selection PPTP or L2TP, the following parameters will be available for
changing:
–
Primary access for VoIP
–
when checked, interface of the primary access will be
used for operation VoIP application; flag is active only when VoIP is disabled;
–
Access type
– access type to PPTP-server. Two variant is possible: dynamic access,
when IP-address and other required parameters are obtained via DHCP protocol
and static access in this case IP address, subnet mask, DNS server, gateway and
other required parameters for access to PPTP server are assigned manually;
–
IP Address
– when the static access is used, VPN server will be accessed from this
address;
–
Netmask
– subnet mask for static access;
–
Gateway
–
gateway IP address for static access, it is used for access to VPN-server
(if VPN server is located in other subnet);
–
DNS Server
–
server of names for static access, that is used in provider local
network;
–
PPTP/L2TP Server address
–
IP-address or domain name of VPN server;
–
User Name
–
user name for authorization on VPN server;
–
Password
–
password for authorization on VPN server;
–
MTU
– maximum size of data block transmitted through the network. 1462 is
recommended value for PPPTP protocols and L2TP.
1
IPSec is not supported in the current firmware version.
