FTTC Router Sync Status

Overview

'Sync' is your modem's ability to talk to your local green cabinet. Most, if not all, modems/routers will have a LED that shows the sync status. This is often the LED labeled DSL, and generally speaking on is in sync, and flashing or off means no sync.

Knowing the Sync status

This can help diagnose a fault, as if the router is not in sync then the problem lies between the router and the your local green cabinet. It could be:

• the router
• the wiring between the router and the main phone socke
• a problem with the actual phone line between you and the cabine
• or even a fault with the cabinet itself.

It does mean though, that the fault is unlikely to be with your computer or your internal network.

Finding the Sync Status

This is a table of popular VDSL/FTTC modems and routers and how you can tell if they are in sync or not by looking at the LEDs on the device. You can often gain more information by looking at the diagnostic pages on the router's web interface, but this will help you tell at a glance if the modem is in sync or not.

Modem/Router	Sync LED Label	In Sync Status	No Sync Status	Notes
Openreach Modem	DSL	Constant Green	Flashing green or off	ECI or Huawei
ZyXEL VMG1312	DSL	Constant Green	Flashing when trying to sync	Orange if it's syncing to ADSL
Technicolor TG589vn	Broadband	Constant Green	Flashing when trying to sync
Billion 8200N	DSL	Constant Green
DrayTek Vigor 2760n	xDSL	Constant Green	Flashing when trying to sync
FRITZ!Box 7390	Power/DSL	Constant	Flashing when trying to sync
Asus DSL-N66U N900	DSL	Constant on	Flashing when trying to sync