Preliminary Release
the user with a list of RTU MAC addresses. Only packets destined for authorized RTUs on the
MAC table are forwarded. The remote radio can also be configured for RTU filtering. This causes
the remote radio to forward only packets back over the RF link when they are sourced by an
authorized source RTU MAC address. This also greatly reduces the probability of system
flooding.
The combined RTU and Host screening mode provides the greatest amount of filtering. Only
authorized traffic has access to the radio address with both source and destination MAC
address complying with the system definition. This makes system flooding nearly impossible to
occur.
6.2.2 Telnet Radio Configuration and Diagnostics
The primary mission of the 2288 is to provide robust RF linkage with total protocol
transparency; however, a Telnet server for local and remote radio configuration is provided in
each 2288. Thus, each 2288 is factory-assigned a unique Alligator MAC address for IP access
using the Telnet protocol. The user is able to program the IP address, gateway address, subnet
mask, and Telnet port address. This gives the radio visibility to the host and/or a separate client
host for radio configuration and diagnostics. Users of RS-232 interfaces also use the Ethernet
interface with a Telnet client program. The Telnet communications over the RF link shares the
bandwidth of the system transparently.
6.2.3 Graphics Heavy Communications
The use of communications carrying a large amount of graphics data is discouraged. Please be
aware that at 9600 bps, the transmission rate is only about 1K bytes per second. Sending large
graphics files can take tens of seconds. This can be done concurrently with the normal polling
traffic along with Telnet diagnostic traffic, but at the cost of system
time
latency. Nothing
prohibits doing large file transfers, but be aware of the time required to push the data through
a 9600 bps link. IP addresses associated with this type of traffic should not be placed in the QIP
table (see 6.2.4).
6.2.4 High QOS (Quality Of Service) IP Communications
IP packets can be assigned high QOS status. This is performed by storing the IP address in a QIP
table. These tables reside in both the master and remote radios. Up to 16 IP addresses can be
saved in the QIP table. This table normally contains the IP addresses of hosts that are polling
remote RTUs and require low timer latency. RS-232 packets are assigned high QOS by default.
Alligator Communications Model 2288 Technical Manual REV3.0 Copyright © 2018
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