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If clocking is not set on a Router serial link, can this affect connectivity?

What does the clocking have to be set to?

Our clients keep having intermittent connection to the WAN.


Hall of Fame Super Bronze

Re: Clocking

On a serial link, a device needs to provide the clocking. Often, this service is provided by the service provider.

I recommend opening a ticket with your service provider and find out if they are providing clocking for your service.

Is this a point-to-point link or just an internet circuit ?

Hall of Fame Super Gold

Re: Clocking


Which type of interfaces do you have? For example serial interfaces with V.35 cables to DCE alway take clock from circuit and connot be set any other way.

If you have T1 or E1 interface you could set clock internal however the normal operation with telco circuits is external.

Do not assume problems are due to clocking, you have to look at show interface and show controller in it's entirety.


Re: Clocking

Going back to my Telecomm 101 fundamentals, Clocking is required to syncronize the data as it travels along the WAN circuit. You must have a central poing of clock that will be the master clock for you whole network. Inn most cases it is the Carrier that provides the line for you. However some companies use their own Stratum 1 or Stratum 2 systems that clock their networks. In the case of a Point to Point T-1 line (if in your house and not provisioned by a carrier) using straight copper then one end must be set for internal clocking and the other end set for line clocking. If your line is from th carrier then both ends can clock off the line. If your clocking is not set correclty then you will receive bit errors and clock slips on the T-1 line. This causes errors on the data. Hope this answers you questions.. Good Luck.. Pls rate...