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7. Broadcasting

Any packet (message) entering the MORSE network can be labelled as a broadcast one. Either the user labels selected packets, or it is possible to set labelling of all packets coming through the user part of the respective CNI (Channel to Node Interface). Once a broadcast packet enters the network, it is spread around following (B)c menu settings of all the nodes that receive it.

With careful settings in all network nodes it is possible to achieve the ultimate goal of broadcasting – to deliver a message simultaneously to all network members – even in large networks with a complex architecture.

When a broadcast packet is transmitted in the RF channel, every receiving CU delivers it to the respective node (to all 5 nodes in radio part). There it is checked for the source address first. If the source address corresponds with the node settings (src base & mask), the packet is multiplied and delivered simultaneously to different node outputs according to the (B)c menu settings.

For example, let us have the user and net node outputs switched on. The received (and checked) broadcast packet is then delivered to the user channel and simultaneously to the retranslation network channel. The latter is typically the RF channel, so in this example the packet will be transmitted on the RF channel again. Using the configuration described above, even broadcast packets can exploit store-and-forward repeaters. Of course an effective algorithm for discarding repetitive packets is implemented.

From MORSE Main menu type B e Enter Enter .

  Multicast routing (Broadcasts):
Nid|src base  mask    u|l n N   a 
(0) 00000000 FFFFFFFF  |    - 00000000
(1) 690F0010 FFFFFFF0 u|  n - 690F0003
(2) 00000000 FFFFFFFF  |    - 00000000
(3) 00000000 FFFFFFFF  |    - 00000000
(4) 00000000 FFFFFFFF  |    - 00000000

type 1 Enter

Multicast routing (Broadcasts):
(s)ource base addr:690F0010  (m)ask:FFFFFFF0
(u)ser output:ON  (l)ink output:OFF
(n)et output:ON (N)ode ID:255
next (a)dr:690F0003
(s)ource base addr: 690F0010

— Base address compared to the source address of the received packet

(m)ask: FFFFFFF0

— Only masked parts of the (s)ource base addr and the packet source address are compared

(u)ser output: ON

— Switch for sending a packet copy to the user output of the node

(l)ink output: OFF

— Switch for sending a packet copy to the retranslation link output of the node

(n)et output: ON

— Switch for sending a packet copy to the retranslation net output of the node

(N)ode ID: 255

— Switch for sending a packet copy to the next node within the same CU (No.0 to No.4, whilst 255 means no next node).

next (a)dr: 690F0003

— When a broadcast packet is sent to the retranslation net output, this address denotes the node from which the acknowledgement will be expected (this is used for secured transfer of a broadcast packet between repeaters on an RF channel). Next(a)dr:0 means no acknowledgement will be expected (unsecured transmission)

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