Ahh you’re an alarm guy! We have issues all the damn time on voip, sia seems to fix most the VoIP issues as long as it’s a non facilities based VoIP provider like utility, or some providers with an analog handoff you can specify the G711ulaw audio codec. But cellular is so much nicer, we push alot of the napco starlinks. the old one at that job was a firelite ip communicators almost like a 411, think you even had to use the pro-411. Reporting into a surgard system iii at the time I think