PRI questions and Clocksource option 11

I have an asterisk voip pbx and an option 11 tied together via 2 PRIs,

each can dial the other with 8

ext 201 exists in each

if option 11 201 dials 8201, it will got to asterisk and asterisk has been told to dial two extensions for asterisk 201

asterisk 201 and 8201, which causes asterisk 201 and nortel 201 to both ring

this means two channels on the pri are used, the 11 calling asterisk and the asterisk calling back to nortel 201

in the d-channel on the 11 it says that NUMPLAN is E164 on the call from the 11 to asterisk but it says E163 on the return call from asterisk to the 11, don't know what this means or the significance if any

both are setup as EES5 switches on the pri.

My other question is clock INT vs EXT on the 11, ld 17 says CLOCK EXT, I don't see how I would change this if I wanted to and make it INT, perhaps it is a function of other settings like PRI type, switch type or trunk types ?

In any case ,works for me for right now because the trunks are on asterisk so it it the master, just wondering how to change it to internal if I wanted to or if I can.