Q-Flex Satellite Modem Installation and Operating Handbook
6-61
6.2.3.4 Point-to-multipoint Mode
The modem can be used in a point-to-multipoint mode where the hub modem sends a
shared outbound to several remotes. The inbounds from the remotes are processed by
individual demodulators.
Hub
Sets up a modem at the hub to be part of a point-to-multipoint
system. All modems at the hub site, even if configured for Rx
operation only, should be set to this mode (or one of the other hub
modes described below).
Remote
Sets up a modem at a remote site to work point-to-multipoint. All
remote modems that form part of a point-to-multipoint system
should be set to this mode (or one of the other remote modes
described below).
Hub
+
TCP
acceleration
This enables point-to-multipoint TCP acceleration. The hub Tx
modem should be set to this mode and VLAN filtering should also
be enabled on this modem. Note that hub Rx-only modems in a
point-to-multipoint TCP acceleration system should be set to
Hub
mode (not
Hub + TCP Acceleration
) and that the Rx-only modems
should have VLAN filtering disabled.
Remote
+
TCP
acceleration
For remote modems, this enables point-to-multipoint TCP
acceleration. All remote modems should be set to this mode and
VLAN filtering should also be enabled.
Hub + Bridged TCP
acceleration
This mode is similar to
Hub + TCP acceleration
but preserves the
original Ethernet frames over satellite (allowing, for example, s
TCP acceleration of any number of VLANs and acceleration of
MPLS streams). In this mode, for ease of use, there is no need to
enter an IP address for the IP Traffic port
.
Since the TCP packets
are bridged over satellite, there is no need to set up static routes
or gateways.
Remote + Bridged
TCP acceleration
This mode is similar to
TCP acceleration
but preserves
the original Ethernet frames over satellite. The IP Traffic port does
not have an IP address in this mode
.
Static routes and gateways
are not required.
Table 6-63 Point-to-multipoint Mode
6.2.3.5 VLAN Filtering
VLAN filtering is used in point-to-multipoint mode only, in order to ensure that just the
relevant packets are processed at each remote site, with all non-relevant packets being
discarded. The hub modem will automatically add the appropriate VLAN tags to the
packets to to be transmitted to the remote modems. Filtering out irrelevant packets at the
remote sites stops them circulating in the wider network and potentially causing packet
storms.