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Dave9's avatar
Dave9
Contributor III
3 years ago

List of all CM-STATUS event type codes with explanations

If you're trying to read your modem logs and wonder what the CM-STATUS event codes mean, here is a list. If you want to know more, read the specification document at this link: https://www.cablelabs.com/specifications/CM-SP-MULPIv3.1

CM-STATUS Event Type Code

Event Condition

Event Trigger

0

Reserved

 

1

Secondary Channel MDD timeout

Lost MDD Timer expiry of a secondary channel advertised as active in the primary channel MDD.

2

QAM/FEC lock failure

Loss of QAM or FEC lock on one of the downstream channels advertised as active in the primary channel MDD.

3

Sequence out-of-range

Receipt of a packet with an out-of-range sequence number for a particular DSID.

4

Secondary Channel MDD Recovery

Receipt of an MDD on a Secondary channel advertised as active in the most recent primary channel MDD.

5

QAM/FEC Lock Recovery

Successful QAM/FEC lock on a channel advertised as active in the most recent primary channel MDD.

6

T4 timeout

Expiration of the T4 timeout on the CM.

7

T3 retries exceeded

The number of T3 retries as specified in Annex B is exceeded.

8

Successful ranging after T3 retries exceeded

Successful ranging on a channel for which T3 retries exceeded event had been reported.

9

CM operating on battery backup

CM detects loss of A/C Power for more than 5 seconds and the CM is operating on battery backup.

10

CM returned to A/C power

CM detects the presence of A/C Power for more than 5 seconds and has returned from backup battery to operating on A/C power.

11

MAC Removal Event

The CM has determined that one or more MAC addresses need to be removed due to a specific CMCI port transition. (ifOperStatus transitions from 'UP' to 'DOWN')

12-15

Reserved for future use

 

16

DS OFDM profile failure

FEC errors were over limit on one of the assigned downstream OFDM profiles of a channel

17

Primary Downstream Change

Loss of Primary Downstream followed by successful acquisition of a backup primary downstream channel as the new primary downstream channel

18

DPD Mismatch

The CM detect the mismatch between the LSB of DPD change count and NCP odd/even bit

19

Deprecated

 

20

NCP profile failure

FEC errors were over limit on NCP

21

PLC failure

FEC errors were over limit on PLC

22

NCP profile recovery

FEC recovery on NCP profile

23

PLC recovery

FEC recovery on PLC channel

24

OFDM profile recovery

FEC recovery on OFDM profile

25

OFDMA Profile failure

CM not able to support certain profile because the profile is out of modem capability when it gets a UCD containing profile definition changes.

26

MAP Storage overflow indicator

The MAPs received by the CM contain more information elements than the CM can support.

27

MAP Storage almost full indicator

The CM's internal MAP storage capacity is filling up.

28-255

Reserved for future use

 

 

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    • Dave9's avatar
      Dave9
      Contributor III
      3 years ago

      It's all in that 900 page document I linked. But even understanding that document requires a lot of general technical knowledge. I understand some of it but not all of it. For example, this is the definition of NCP:

      5.2.2.1.2 NCP
      The Next Codeword Pointer (NCP) is a portion of the downstream OFDM channel which is dedicated to carry information about the mapping of FEC codewords to subcarriers within a symbol. NCP is  generally considered a part of the Downstream Convergence Layer. [DOCSIS PHYv3.1] includes a detailed description of the NCP. The NCP references in the MULPI specification are limited to the DPD message which is also used to specify a profile for NCP as well as to performance monitoring and failure reporting protocol.

      FEC is a bit easier to understand:

      Forward Error Correction FEC enables the receiver to detect and fix errors to packets without the need for the transmitter to retransmit packets.