Fax cuts off Ext?

[etel]

I have a SCN network 406v2 at both ends running 3.2.57, point to point T1 connecting them together. The calls come into the PRI at site A then routed over the point to point to site B. When a call comes into FAX A at site B at times it will cause ext 221 to be unable to hear the call they are on. Once the fax ends the call returns to ext 221. I have changed ports on both run a new cable and still the problem happens. The hard part about it is it does not happen every time.

Thanks for any suggestions.