Specifications

249
OPARAM Programming/TNPP Networking Using Version 8TNPP8C3
The node addresses remapping uses two additional fields in a node routing entry to control
remapping. The first field is used to specify the ports for which remapping is active. If the
port's bit is set on then packets received at that port with the oparam line node ID as the
packet destination node ID will be remapped. Remapping is done by replacing the packet's
original destination address with the “remap to” address, which is the second field of the
remapping fields.
If the new, remapped to, address is not in the node routing table then the “route to” bits of
the original destination address will be used. If the new node address has an entry in the
node table then that entry's “route to” bits will be used to route the remapped packet.
The overall effect of this simple remapping is that the Node IDs generated in Central are
changed to the needed node addresses. A very simple example of this is shown in the
following sample. There is only outgoing routing, all pages to this terminal are addressed
to its primary node ID and use the implicit routing to Central for packets addresses to out
primary node ID.
0C 01 09 05 03 06 00 00 00 00 00 00 ; Duplex, 4800 BPS
; Route Accept Remap Remap to
; node 0502 To From For Port Dest address
0C 00 10 04 00 00 05 00 00 02 00 01 08 00 01 00 00 10 00
0C 00 10 04 00 00 05 01 00 02 00 01 08 00 01 00 00 33 33
0C 00 10 04 00 00 05 02 00 02 00 01 08 00 01 00 00 02 FF
0C 00 10 04 00 00 05 03 00 02 00 01 08 00 01 00 00 45 67
; we are 1111
0C 00 0A 17 11 11 00 00 00 00 00 00 00 ;
When remapping a node address, the routing information may be changed as well. If there
is a node entry for address 100, and this entry will remap packets received at port two to
200, and there is no explicit node routing entry for 200, then the route-to bits for 100 will
be used for all packets originally targeted to 100.
However, if there is an entry for 200 then its route-to bits will be used for all packets that
were originally targeted at 200, as well as any packets that are remapped from 100 to 200.
In the example shown in the following sample, destinations 0500 through 0503 will be
remapped. Two of the new, remapped addresses have node table entries. Packets remapped
to these two destinations, 3333 and 4567, will receive the routing information of the new
destination. For the example these packets will be routed to ports 0 and 2, noting that the
normal stripping of the source port's bit will occur.
0C 01 09 05 03 01 00 00 00 00 00 00 ; Duplex, 1200 BPS
0C 02 09 05 03 01 00 00 00 00 00 00 ; Duplex, 1200 BPS
; First set up the remap node ID information
; Route Accept Remap Remap to
; node 0502 To From For Port Dest address
0C 00 10 04 00 00 05 00 00 03 00 03 08 00 01 00 00 10 00
0C 00 10 04 00 00 05 01 00 01 00 03 08 00 01 00 00 33 33
0C 00 10 04 00 00 05 02 00 03 00 03 08 00 01 00 00 02 FF
0C 00 10 04 00 00 05 03 00 01 00 03 08 00 01 00 00 45 67
; Then the routing for two of the remapped addresses - send to port 2
0C 00 0A 04 00 00 33 33 00 05 00 03 02
0C 00 0A 04 00 00 45 67 00 05 00 03 02
; we are 1111
0C 00 0A 17 11 11 00 00 00 00 00 00 00 ;
An increasing number of terminals are both receiving Network USA paging, either from
their own downlink dish or from some other node, and sending pages to Network USA's
uplink node. This situation requires some care in setting up, as the pages sent to Network