Q-Flex Satellite Modem Installation and Operating Handbook
7-12
4. The M&C IP address and the traffic IP address should be on different subnets. The
modem defines one default gateway. If the second subnet also requires a gateway
then a static route should be added that defines a gateway for that subnet.
On the 1:1 Standby modem, the carrier is muted, as is the satellite receive port (in order
to ensure that no received data is passed out of the terrestrial port). The M&C port and
the terrestrial IP traffic port are not muted.
If a switchover occurs when in bridging mode, the Standby modem will automatically
learn to bridge the traffic as necessary, once it comes on line.
If dynamic routing is being used when a switchover occurs then the route through the
newly online modem will be learned automatically.
If static routing is being used then the M&C system will need to detect that a switchover
has occurred and update the routes accordingly for the new IP address associated with
the online modem. Some network devices support route failover, which automates this
process. In this case the M&C system router that supports route failover should be
configured to include another route in the routing table with a higher ‘metric’ or ‘distance’
for the route that uses the Standby modem’s IP traffic address. The switchover to using
the Standby modem will then be automatic when it detects the path through the primary
modem is no longer available.
7.3.4.2 1:N IP Operation
The following rules should be observed when using 1:N redundancy for IP.
5. In 1:N mode, the M&C IP addresses need to be different for each modem.
6. In 1:N mode, the IP traffic addresses should be set to be the same in both
modems. The IP traffic port on the Standby modem is physically isolated from the
network via a relay contact, which ensures that having identical IP addresses does
not cause any problems.
7. The M&C Ethernet port must not be bridged to the IP traffic port (this is controlled
via the
Bridge M&C
control on the
Edit->IP
screen).
8. The M&C IP address and the traffic IP address should be on different subnets. The
modem defines one default gateway. If the second subnet also requires a gateway
then a static route should be added that defines a gateway for that subnet.
On the 1:N Standby modem, the carrier is muted. The IP traffic port remains active but is
physically isolated from the network. The M&C port is not muted, allowing the M&C
system to control the Standby modem at all times.
The switchover operation in relation to bridging and routing is similar to that for 1:1
operation.
7.4 Software Activated Features
While some modem functions are available as plug-in option cards, the majority of
additional functions are made available through Software Activated Feature (SAF)
support. As the name implies, these are modem features that can be enabled by entering
a feature code via any of the modem’s user interfaces. Feature codes are encrypted
