First off thank you for helping. I am working on a job that the customer has verizon fios for there phones . They have 2 issues one is they dropped calls sporadically and the other is they get a buzzing sound when answering the phone sometimes. The buzzing sound i believe is a timing issue.

I connected to the demarc of the phone company and cannot duplicate either of the issues. However my phone guy states the issue is with verizon. What can i do to fix this. I did have a vendor/phone company meet they both came here and we isolated it to the phone system. When we contacted vertical they said it is a know issue with verizon fios and to change from sip to pots which i did and i am still having the same issues