Hello. We have a Cisco 3640 router at one of our hub sites. It has four network modules with two 2MFT-T1 WIC modules each (16 ports total). We continuously have timing-related problems (slips, Line Code Violations, Path Code Violations) with some of the T1 circuits that are attached. We have confirmed that our telco provider does not provide any clocking on our T1 circuits so we typically pull clock source from one side or ther other, then pull it from the line on the other side.
It seems that the options available "clock source line", "clock source line primary" and "clock source internal" all depend on which port the T1 is connected to, or what other T1s are connected in the same WICs, or in the same network modules.
Has anyone ever understood the clock source options and how they relate to WICs, Network Modules, etc.? If so, I would love to know if there is any type of definitive guide available.
Thank you in advance.
Tony