4RF Aprisa SR+ User Manual - page 24
About the Radio | 21
Aprisa SR User Manual
Network Layer
Packet Routing
Packet routing is realized in the Aprisa SR by adding a network address header to the packet. This contains
source and destination addresses. For the Network Layer, there are 2 addresses, the address of the
originating radio and the address of the terminating radio (i.e. end to end network). This is required for
routing packets across multiple hops e.g. PMP with repeaters.
The Aprisa SR uses an automated method for performing address assignment and routing information.
There are two types of packets: unicast and broadcast. Only the Base Station sends broadcasts which are
received by all Remote Stations. User packets are not interpreted as the radio link is transparent.
Traffic
Data originating on the Base Station is broadcast to all Repeater Stations and Remote Stations.
Data originating on a Remote Station is unicast to the Base Station only. This can be via multiple Repeater
Stations.
Data originating on a Repeater Station is unicast to the Base Station only.
Data originating on a serial port is terminated on a serial port and data originating on an Ethernet port is
terminated on an Ethernet port only.
User Traffic
User traffic is prioritized depending on the Serial and Ethernet Data Priority options (see ‘Serial >
Advanced’ on page 91 and ‘Ethernet > Advanced’ on page 98).
If the Serial and Ethernet Data Priority options are equal, then first come first served is invoked.
Repeater stations repeat traffic also on a first come first served basis.
Management Traffic
Ethernet Management Traffic has the same priority as Ethernet User Traffic but if the radio is not licensed
for Ethernet, the Ethernet Data Priority is set to Low.