Quantum and Evolution Series Installation and Operating Handbook
7-178
onto the local terrestrial IP network. Note that the use of point-to-multipoint VLAN filtering
relies on the modem generating and removing VLAN tags and it cannot therefore be used
in situations where VLAN tags are already present in the data at the point at which it is
passed to the modem for transmission.
On the menus, the
VLAN ID
option is used to set the identifier to be used with VLAN
filtering. 4094 VLAN ids are available.
The
Bridge M&C
mode ensures the M&C IP interface is part of the Ethernet bridge. If
deselected, then the IP traffic and M&C are kept separate.
Web Acceleration
mode accelerates web browsing by prefetching web page inline
objects prior to them being requested by the web browser. This feature requires the
modem to be fitted with an IP traffic card. It also requires a DNS IP address to be set.
Web pages comprise multiple objects which are typically fetched one or two at a time by
a web browser without web acceleration and therefore a full webpage can take many
times the satellite delay to be displayed. The Paradise web proxy examines webpage
frames as they pass through the modem and pre-fetches all of the content before it is
requested. It is therefore typically available in cache memory at the modem local to the
web browser prior to the browser actually requesting the remaining content.
The
Bridge Filtering
option forms part of the Brouting traffic mode and controls whether
the Ethernet bridge filters out all the traffic other than that destined for the local sub-net. If
this option is switched off, then it is typically the responsibility of a router on the local
network to filter out unwanted traffic.
The
One for one mode
option is applicable only to the G.703 interface. Normally the
G.703 input is looped by a relay if power is removed. This is to ensure that any other
traffic on the G.703 PCM bearer is not lost by a break in the bearer. However, when one-
for-one mode is selected, the G.703 output goes high impedance if power is removed
allowing the units 1:1 partner to carry the traffic.
7.4.5 Timeslots
Timeslot selection and reordering has been simplified by the use of edit boxes for each
timeslot, as shown overleaf. The boxes allow the association of specific terrestrial
timeslots with satellite timeslots.
