4RF Aprisa SR+, Product Description

Page: 45 / 49

Architecture | 43
Aprisa SR+ Product Description
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 base station serial port is terminated on remote station serial ports only
Data originating on a base station Ethernet port is terminated on remote station Ethernet ports or
serial ports (Terminal Server mode)
User Traffic
User traffic is prioritized depending on the Serial and Ethernet Data Priority options.
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 is also prioritized relative to user traffic.