E F Johnson Company 2424140 Benutzerhandbuch

Seite von 73
SECURE COMMUNICATION (ENCRYPTION)
70
TEKs and only one is active at a time. Keyset ID 255 
is for KEKs and is considered active all the time
Each keyset can have up to 128 keys. However, 16 
or less are normally used. 
AES encryption is supported (with Flash code 1.8.0 
or later) but not currently available with OTAR 
(future availability is planned).
RSI (Radio Set Identifier)
One individual RSI and it is usually initially the 
same as the P25 Unit ID.
One group RSI (usually initially “0”).
One KMF RSI (usually always 9,999,999).
OTAR Messages That Are Supported
The following KMM Message IDs are recognized 
by or sent:
CHANGE RSI
0x03
CHANGE RSI RESPONSE
0x04
KEYSET CHANGEOVER
0x05
KEYSET CHANGEOVER RESPONSE
0x06
DELAYED ACK
0x07
HELLO
0x0C
INVENTORY
0x0D
INVENTORY RESPONSE
0x0E
MODIFY KEY
0x13
MODIFY KEYSET ATTRIBUTES
0x14
MODIFY KEYSET ATTRIBUTES RESPONSE 0x15
NEGATIVE ACK
0x16
NO SERVICE
0x17
REKEY ACK
0x1D
REKEY
0x1E
WARM START
0x20
ZEROIZE
0x21
ZEROIZE RESPONSE
0x22
10.6.2  UCM EQUIPPED 4100
The 41xx UCM version uses the Motorola UCM 
encryption module. Therefore, the OTAR capabilities 
are determined by that module. All capabilities of the 
Motorola KVL and KMF are supported. Initial radio 
programming by the PCConfigure software is the 
same as described in 
Section 10.5. 
10.6.3  OTAR OPTION SWITCHES
The following additional option switches can be 
programmed with the 4100 portable and 4300 mobile 
to control OTAR functions. They are also available as 
4100 menu parameters unless noted otherwise.
Change Keyset - Toggles the active keyset between 
Keyset 1 and Keyset 2. The new active keyset is 
briefly displayed and then normal operation resumes. 
When the 4100 menu is used, the current active keyset 
is indicated by an asterisk. To change to the other 
keyset, highlight it and press the F2 key.
Clear/Secure Select - This enables and disables 
encryption regardless of whether OTAR is used. Refer 
to Section 10.3 for more information.
Erase Keys - Erases all TEK and KEK keys contained 
in the radio. With the 4100, this function is available 
as menu parameter only.
Key Select - This allows a different key to be selected 
for the current channel or group (conventional chan-
nels only). Refer to Section 10.2.5 for more 
information.
OTAR Rekey Request - Sends a message which tells 
the KMF that the radio is on the air and requests 
rekeying. The following status messages are displayed 
which indicate the progress of this function. Addi-
tional functions that are available when this is selected 
using the 4100 menu mode are described in the next 
section.
Rekeying - A radio-initiated rekeying session is in 
process.
No Ack - No response was received from the KMF 
in response to an Identify request before time out 
occurred (approximately 30 seconds). 
Ack Rcvd - An acknowledgement was received in 
response to an Identify request. 
No Service - A “No Service” reply was received 
from the KMF. No rekeying will take place.