You can set E1 and E2 for the Orderwire;
For Case 1, the first call uses E1, the second call uses E2, there is no conflict.
For case 2, this 2 calls just to adjacent NE, they use different fibers, so there is no conflict also. but imagine there is more than two or three NEs between main
station, we can get the orderwire connection between mentioned NEs