Specifications

187
Laying Out the Network
On the other hand if subscribers had been assigned coverage areas by entering the
addresses of all applicable nodes then adding a new node to a coverage area would involve
adding that node address to all the subscriber IDs that have that coverage.
Each terminal has a file that enables it to convert the region name into one or more
network node addresses. Normally only one node address per coverage region will be
needed, using secondary node addresses in a page and pass mode. Some vendor’s
terminals do not support secondary addresses or page and pass mode. In these cases, it will
be necessary to map a coverage region name to several node address values. One node
address would be the page and pass secondary ID, and the others would be the specific
node address for each of the terminals that do not support page and pass. On those
terminals the page and pass node addresses for the Series 2000 terminals would be set up
to just route through the other vendor’s equipment, being passed along the network as
needed.
Each terminal also is programmed with information telling it how to route each node
address in use. In the example all terminals would both page locally and be routed through
the network card to the next node in line any packet with a destination node ID of the
P5ALL node address (0500). The P6ALL (0600) would be treated in a similar fashion,
except that nodes 5092 and 2021 would just route the P6WIDE packets on through
without attempting a local page.
The final result of this example network looks like this:
Figure 43: Overlapping Network Coverage
If 4161 and 5091 sign up the road service crew, which keeps the highway across the north
end of the state open in winter, they could easily add a new coverage region. The two
interested nodes would add the region’s name to their local tables, and define the new
node address properties such as what local channel and zone to use. The intervening
nodes, 4162, 2021, 5093, and 5092, would need to add the new region’s node address as a
route- through ID.
4161
4162
2021
5093
5092
5091
P6WEST P6ALL P6EAST
P5WEST P5ALL P5EAST