Traffic prices are set with plan edit wizards.
Note: free GB of traffic set explicitly for two and more month billing period are not divided by the duration of the billing period in months.
E.g.: setting 10GB free for two month billing period, you allow your customers to run each month 10GB (not 5GB) without being charged.
* When increasing plan's free traffic, use mass mail to let the customers under this plan know they need to increase their traffic limit to new free in their user CP without any charges.
* When decreasing plan's free traffic, use mass mail to let the customers under this plan know they need to decrease their traffic limit to new free, otherwise they will be charged recurrent fee.