when to set E1 PRI clock source?

[t-alkhalidi]

hi all,

does any one know based one what i set the clock source to external or internal?. actually im connecting to Voice provider with E1 Line. should i ask the provider if they are the clock source? and if yes they provide the clock , then under the vwic should i use command clock source Line/internal??.

i appreciate if any experts could explain to me this paramter

[Chris Deren]

You should always clock of off telco equipment, leave the controller in default "line". Use network-clock-select command to specify clock preference.

HTH,

Chris

[t-alkhalidi]

thanks for the info below. so most of telco is clock source master?, so when i specifiy line in the gateway and external in call manager thats mean the router is slave for the clock and master or source of the clock is telco. ok when i make it internal it means the clock source is the router incase the telco not providing clock, im right?