I am currently setting up Level3 as a provider of SIP Toll-Free services. I am hearing from my account team that they don't have any option other than their BusyNoAnswer option to failover from one SIP IP (on my side) to another. If I send back a 486 or there is a timeout they can failover to a second trunk. Unfortunately, they can't decouple the 486 and timeout scenarios. and that doesn't work, because 486 is a normal non-error condition on my network and I wouldn't want the call to be re-presented to another location just because the first location sent a BUSY. I have asked them if they can failover on 5XX errors or internally generated 408, but they seem to think they are unable to do anything like this. Anyone have any experience with Level3 in this scenario? Thanks, Geoff