User's Manual

Radio Operation
Crescendo VHF Half-Duplex User Manual Page 28 of 74
5.4.3 Store-and-forward Repeater
A Crescendo unit may be configured to operate as a store-and-forward repeater (see Appendix B.1). A store-
and-forward repeater can be used to extend the range of a network. It behaves as a combination of base and
remote unit in the following manner:
If a packet is received over the air which is addressed to the repeater, the packet data will be
transmitted out the serial port.
If a packet is received over the air which is not addressed to the repeater, but with a next hop
address equal to the repeater‟s address, the packet will be submitted for retransmission.
If a packet is received over the air which is addressed to the broadcast address, the packet will be
submitted for retransmission, and the packet data will be transmitted out the serial port.
When setting up a network with store-and-forward repeaters, it may be necessary to adjust the following
parameters on units in the network:
Repeaters in Network.
Wait for Carrier.
Routing Tables
Routing traffic to take advantage of store-and-forward repeaters is covered in section 5.5 on page 28.
5.5 Routing
Routing of data operates differently depending on the protocol mode that is selected (protocol modes are
covered in section 6 on page 33):
Data Driven Protocol: When operating in data driven protocol, all data received on the main serial
port of a unit is transmitted out the main serial port of all other units in the network. The routing
table has no impact on data driven operation.
Point-to-Multipoint Protocol: When operating in point-to-multipoint protocol, all data inserted on
the serial port of the base is output on the same serial port of each repeater and remote within the
network. The routing table has no impact on point-to-multipoint operation.
Point-to-Point, Hayes Dial-up, and Datagram Protocols: When operating in any of these protocol
modes the routing of data is governed by the network structure and routing table.
5.5.1 Network Structure
A typical Crescendo network has a base and store-and-forward repeaters forming a backbone, with a set of
remotes hanging off the base and each repeater. In order for a packet to reach its destination, routing tables
need to be configured on the units.
Main -> Radio -> Network