Why not? Personally I enjoy SIP itself greatly, it works well and is basically human readable, to the point that I can explain it to non-technical people. My

Why not? Personally I enjoy SIP itself greatly, it works well and is basically human readable, to the point that I can explain it to non-technical people. My main problems over 15 years of working with SIP have been with "helpful" boxes in the middle tampering with my SIP messaging. NAT used to cause a bunch of problems, but these days I have workarounds for most cases that work great until the aforementioned middleboxes start "helping". Give me a NAT-free network where the packet that reaches the far end is the same one I sent and my SIP systems will be quite happy.