Crappy side of the new IOS Voice SIP secuirty

As we all know, SIP has become a target of hackers as they are able to break into networks and steal resources. I've had the pleasure of working a few Toll Fraud cases in my years. Today I got a call that someone's inbound dialing had stopped working. Turned on some debugs and it showed my cell phone number was getting rejected. Thats weird. I made a call to the SIP provider and asked them to watch some inbound calls for me. They saw the same thing. I asked them if they had changed there IP recently and they said on Tuesday!!!!!!!!!!!!!!!. WTF. They sent out notifications, but my customer doesn't read the mail. This was a pretty quick and easy fix. The problem is with the new VOIP security in IOS it only accepts IP address at this time. Hopefully cisco will implement putting in domain names.