The answer is Yes there are related, blocking swithing has to do with it.
A switch (lets say telephonic exchanges) has a switching matrix which is designed to have a GOS of 1/100000, it is designed on several issues:
Performance of the processor
Traffic capacity for trunks groups (E1 and suscriber lines that produce BHCA).
Call service processor performance
Size of memory to handle simultaneous calls and services, etc.
The mathematical model is so complex that is hard to describe, The model I saw 10 years ago was complicated and oriented to vendor technology, other vendors follow similar model with some deviations in accordance their own switch arquitecture.
Comments or corrections are welcome