New network set up and OTAR issues

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alexn
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Posts: 2
Joined: Tue Sep 18, 2012 6:48 am

New network set up and OTAR issues

Post by alexn »

Hello all, I'm Alex, new to the board, and have an issue right now performing OTAR in our network. This is a write up from a collegue, which explains the issue -

The OTAR issue is as follows:
OTAR (over the air rekeying) is a function of the radio network that allows new encryption keys to be sent to the users portable radios in the field. The keys are changed monthly for approximately 9000 radios.
*Normal Operation
When an OTAR is initiated, the data signal is sent from the user radio to the geographically closest Quantar on that channel. The data signal is then sent to the Astrotac Digital Voting Comparator (DVC). The DVC recognizes the signal as data, and not voice, and then transfers it to the Digital Interface Unit (DIU). The DIU recognizes this as OTAR data and routs it to the Key Management Facility computer (KMF) via the Radio Network Controller (RNC) and Wireless Network Gateway (WNG). The WNG will respond to the traffic first, acknowledging the user radio which prompts the user radio to transmit the next data packet, known as DATA12. The user radio will then send a second message known as DATA18 that will be replied to by the KMF.
*Running over the MPLS
With the radio network on the AT&T MPLS/Juniper system (AT&T router and Juniper CTP) there are multiple channels that cannot perform the OTAR function.
A test was performed on the San Clemente channel between the Quantar at the Remote Station and the DVC at MW Mountain. All other circuits (Quantar connections) connected to the Remote radio channel were disconnected. When that circuit is on the Sprint/Multiplex system (point to point circuits) we were able to OTAR normally. When the circuit is switched to the new MPLS System the OTAR feature no longer works.
The same problem exists on other channels that we have been trouble shooting for the past couple of months. Multiple channels located at MW2, MW3 and MW4 sites exhibit the same symptoms. The common factor with these sites and channels is that the DVCs are not collocated with the DIUs and the circuits go over the AT&T MPLS Network.
Troubleshooting on the MPLS network has revealed that the DATA12 appears to be working. The user radio acknowledges the response of the DATA12 message. On the RNC and the Astrotac, the DATA18 message is seen but the user radio never receives the DATA18 message.
Not Running over the MPLS
With the radio network on Sprint/Multiplex system OTAR works normally.

From what he has given me, it seems that there are acknowledgements getting to and from the radio, but the packet to start the OTAR process is dying at the DVC and not getting to the radio. Are the packet sizes for DATA12 and DATA 18 different? Are therre any settings or chages that could be made to get the DATA18 packet to the radio at the DIU? Or is there a way to look a logs in the DIU that might tell us why that packet is not being sent?
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xmo
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Joined: Fri Oct 12, 2001 4:00 pm

Re: New network set up and OTAR issues

Post by xmo »

Contact the Motorola ST that performed the system configuration or else call Motorola System Support at 1-800-221-7144.
alexn
New User
Posts: 2
Joined: Tue Sep 18, 2012 6:48 am

Re: New network set up and OTAR issues

Post by alexn »

there was no involved here, just a change from point to point circuits to mpls. Appreciate it though
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