From my router log
2 2014 Oct 25 09:48:08 PPPoE notice PPP: ppp1.1 Connection Up.
3 2014 Oct 25 09:48:07 PPPoE notice IPCP Opening.
4 2014 Oct 25 09:48:07 PPPoE notice PPP LCP Up.
5 2014 Oct 25 09:48:07 PPPoE notice PPP LCP Down. Reason:0 lower down
6 2014 Oct 25 09:48:06 PPPoE notice PPP LCP Up.
7 2014 Oct 25 09:48:03 PPPoE notice Receive PADS
8 2014 Oct 25 09:48:03 PPPoE notice Send PADR
9 2014 Oct 25 09:48:03 PPPoE notice PADO received
10 2014 Oct 25 09:48:00 PPPoE notice Send PADI
11 2014 Oct 25 09:47:41 PPPoE notice PPP: ppp1.1 Connection Down.
12 2014 Oct 25 09:47:41 PPPoE notice PPP LCP Down. Reason:0 lower down
So I definitely lost sync before the errors... but I just realised HG612stats supposedly harvested those stats with the errors at 09:48... at which time I hadnt yet got PPP again until a few seconds later.
My xDSL log shows that each of the spikes from CRC graphs I posted each occurred at the time of the DLM resyncs.
1 2014 Oct 25 09:48:00 XDSL notice VDSL link up. Speed:RX:79987/TX:20000 (Kbps)
2 2014 Oct 25 09:47:32 XDSL notice xDSL PTM link down.
3 2014 Oct 24 07:38:00 XDSL notice VDSL link up. Speed:RX:79987/TX:18999 (Kbps)
4 2014 Oct 24 07:37:31 XDSL notice xDSL PTM link down.
5 2014 Oct 23 10:47:06 XDSL notice VDSL link up. Speed:RX:79987/TX:19001 (Kbps)
6 2014 Oct 23 10:46:40 XDSL notice xDSL PTM link down.
From what I can gather PPP sessions can hang on even when the connection resyncs.
Likewise, the connection can resync before a new PPP session is initiated (sometimes it isn't even refreshed following a resync).
I suppose it's also possible that your modem/router's system time is slightly out of sync with the PC's system time?
Anyway, the reason
HG612 Modem Stats & MDWS report the 5559 CRC errors is that CRC data isn't reset to zero following a resync whereas OHFErr data is reset to zero.
Eric has confirmed that
DSLStats reports OHFErr data for CRC errors & I think he uses the same data for the CRC field when uploading the data to
MDWS.
HG612 Modem Stats records both OHFErr & CRC data separately.
The data in the CRC (OHFErr) graph is actually from the CRC data (showing those errors).
It appears that
MDWS also uses that data.
The OHFErr graph (not currently included in the
FULL__MONTY montage) doesn't show it as it was reset to zero at each resync.
Both graphs do show 923 errors at 02:47 24/10/14 though, due to the fact that the connection didn't actually resync at that time.