Comtech EF Data DMD-2050E - Manual (Page 64)

DMD2050E Universal Satellite Modem Theory of Operation
MN-DMD2050E Revision 2 3–22
Idle
Waiting for
Embedded
Channel
TX OFF
Event: TX ON
Action: None
Waiting for
Key
Agreement
Response
Event: Embedded Channel Active
Action: Send Key Agreement (KA) Message
Waiting for
Key
Rollover
Event: Key Agreement Response message received
Action: Compute TEK, Load TEK, Start Rollover
Encrypting
Event: Transmit Key Rollover
Action: None
Event: Rekey Timer Expired
Action: Send KA Message
Event: Timeout
Action: Resend KA Message
Event: Timeout
Action: None
Event: RX Sync Lost Message received
Action: Zeroize TEK
MnC initiated Mailbox message to
FIPs
FIPs initiated mailbox message to
MnC, MnC responds back once
embedded channel is up or timeout
occurs.
Event: Timer
Expired
Action: Return to
Idle
Need to make timers configurable
FIPs initiated mailbox message to
MnC, MnC tells embedded channel to
set up framing for key roll. Key roll is
negotiated in the encrypted channel
and is a real time signal when new
TEK arrives in frame
Figure 3-9. Traffic Encryption Key Negotiation