Documenting events at the xDSL interfaces

The device generates a SYSLOG entry for each of the following xDSL interface events:

Status	Meaning	SYSLOG severity
xDSL: Booting modem: ...	The modem is restarting.	NOTICE
xDSL: Set up line to <line mode>/<line type>	The xDSL module establishes the connection with the specified mode and type. The following values are possible: Line mode: Disabled, auto and all modes configurable under Setup > interface > ADSL interface or VDSL interface. Line type: POTS, ISDN	INFORM
xDSL: Line is up. DS-Rate: ..., US-Rate: ..., DS-Margin: ..., US-Margin: ..., DS-Attn: ..., US-Attn: ..., Mode: ..., Profile: ....	The modem has successfully established the connection with the shown values.	NOTICE
xDSL: Line data update. DS-Rate: ..., US-Rate: ..., DS-Margin: ..., US-Margin: ..., DS-Attn: ..., US-Attn: ..., Mode: ..., Profile: ...	The modem has successfully resynchronized connection with the shown values.	NOTICE
xDSL: Line data update.	An update of the line data was carried out after one minute.	NOTICE
xDSL: Line disconnected due to ....	The connection is terminated for the shown reason. The following values are possible: modem reboot retrain silence high line error rate protocol setting line type setting automode line type switch modem timeout VC parameter change	NOTICE
xDSL: SNR margin (dB, Down/Up): .../...	The buffer zone between the required and actual signal-noise ratio (SNR) has changed by more than 1dB.	INFORM