Not usually an issue for us. Occasionally an intermediate carrier hosted a number at one time and didn't u provision it when they lost the customer, but that's fairly rare these days. So I agree, 404's are fairly reliable for us. On Oct 21, 2015, at 13:46, Alex Balashov <abalashov at evaristesys.com> wrote: Can't a 404 sometimes be taken as evidence that an intermediate network element (e.g. a wholesale provider's LCR) doesn't have the destination in route? Or do they just return the all-encompassing 503 in those cases? ? -- Alex Balashov | Principal | Evariste Systems LLC 303 Perimeter Center North, Suite 300 Atlanta, GA 30346 United States Tel: +1-800-250-5920 (toll-free) / +1-678-954-0671 (direct) Web: http://www.evaristesys.com/, http://www.csrpswitch.com/ Sent from my BlackBerry. Original Message From: James Milko Sent: Wednesday, October 21, 2015 13:43 To: Alex Balashov Cc: Paul Timmins; VoiceOps Subject: Re: [VoiceOps] Disconnected numbers and SIP _______________________________________________ VoiceOps mailing list VoiceOps at voiceops.org https://puck.nether.net/mailman/listinfo/voiceops