Trouble Calling Verizon Numbers

Hey,

We have a Skype setup, connected to an AudioCodes SBC, connected to SIP trunk provided by Broadconnect. Currently we can make calls to most providers, but calls to Verizon numbers just never go through.

Broadconnect wants us to disable 100rel (which we can't seem to do)

Any ideas how to do that in Skype for Business? Does that even make sense as a strategy? Anyone have similar issues?