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Troubleshooting guide

ManualsBrandsMotorola ManualsComputer equipmentBSR 64000
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BSR Troubleshooting Guide
A-140
Baseline Privacy
Baseline Privacy encrypts upstream and downstream data passed between the cable
modem and CMTS using the shared Authentication Key (AK) and Traffic Encryption
Key(s) (TEKs). The CMTS assigns an AK to a cable modem based on the cable
modem SID. The CMTS AK can be set to expire based on a grace-time or a lifetime
value. The TEK is assigned to a cable modem once the cable modem has a valid AK.
The TEK encrypts data traffic between the cable modem and the CMTS. Each
authorized SID is encrypted with a TEK. The AK and TEK encryption use 40-bit or
56-bit Data Encryption Standard (DES) encryption algorithms. Once the AK and TEK
are accepted by the CMTS, the cable modem authenticated identity is associated with
a paying subscriber and services, the cable modem is authorized to access.
Periodic Ranging
A cable modem performs periodic raging based on a configured time interval. Cable
modems use periodic ranging to make adjustments according to the MAPs sent to
them by the CMTS. This ensures that the cable modem transmits upstream
information within acceptable limits.
A modem monitors the allocation map for Station Maintenance intervals. When the
CMTS sends a ranging request to the cable modem, the cable modem goes through
the ranging process and makes the appropriate adjustments in its ranging response.
During this process, the cable modem continues to forward data over the network.
The CMTS may send an Upstream Channel Change (UCC) to the cable modem after
the cable modem has successfully completed the Initial Ranging process on the
current upstream channel. When the cable modem responds to this request, it
monitors the downstream channel for the new UCD. Once the cable modem receives
the new UCD, it goes through the Initial Ranging process on the new upstream
channel. During the process, no data is forwarded over the network. If Initial Ranging
cannot be accomplished within the configured timeouts and retries, then the modem
goes through the Scanning process.