@Zulu- "Some carriers can give you a PRI handoff from SIP trunks"- I think the problem with this is cost as well. OP is paying $600 per month now and wants to reduce costs. I think this is also a misconception with SIP trunking. It is not always cheaper when you start factoring everything in. Example- just switched from AT&T PRI to Centurylink voice complete; PRI handoff was cheaper than SIP all the way through. They used Verizon for the PRI handoff, and 3 PRI handoffs were WAY cheaper than the 10 Mbps internet drop that they proposed. Considering the points of failure as well- SBC and Firewall. The SBC would be managed by me, the Firewall NOT. And then comes the issue of who is responsible for this data connectivity, me or my network group? Additional issue would be infosec- Constant justification to infosec that the connection is secure, all devices are secure and up to date. It's enough now that there is a HUGE issue with SIPVicious scans, I believe they reported at least 10k hits per day, and asked me what I am going to do stop them. Silly question really....I can't stop them. I rely on the firewall as my edge, so the question is "what are you doing to protect me?" This is where things get really grey. Getting off-track here. Cost, security, ROI...figure out what is best for you. I was speaking to someone just the other day about this. They did a trial of Twilio and saw 3000 scans within 6 hours(mostly originating from China), so they unplugged it; saving a few bucks wasn't worth the risk to them.
