On 2/15/12 3:29 PM, Darren Schreiber wrote:
Hi folks, We have a customer who is insisting on setting their outbound Caller ID to an 800 #. They are complaining that /they /can't call other 800 #s. Our testing reveals that many carriers are refusing to route the call when the Caller ID is set as an 800 #.
There's a reason for that. Many carriers also refuse to route email when the sender claims to be wealthy royalty from Nigeria. If you are a legitimate operation, calling with a TF number as your CLID raises the same red flags as sending email in all caps claiming to be wealthy royalty from Nigeria. They can't call my friend's house, either, without jumping through a hoop. 99% of those calling with a TF caller-ID, 000-000-0000 or anything else not matching the NANP are rogue telemarketing scum who call despite the target number being on the do-not-call list. The other 1% are people like your customer that think it's a good thing to claim to be originating calls from a DID that by definition isn't supposed to originate calls and don't mind raising red flags. I think he also directs calls with CNAM matching the name of any US state similarly. Here's how he handles it. Asterisk does a challenge-response. It answers the phone, says "hello", pauses two seconds to fool the answering-machine-detect of predictive dialers, then plays a recording instructing these callers, if human and not a telemarketer, to hang up and call back within five minutes and enter a 4-digit number generated at random and read to them (which stays valid for five minutes). Humans behind telemarketing dialers may not even know what number they have dialed and don't often have the ability to call back anyway. Legitimate persons calling from a business which has CLID (stupidly, IMHO) set to a TF number generally do know and can call back. If they pass the challenge, it rings the phone. If not, subsequent calls go here... http://www.voip-info.org/wiki/view/Asterisk+Telemarketer+Torture There are a few TF numbers in his whitelist that have passed the challenge, his stockbroker, for example. -- Jay Hennigan - CCIE #7880 - Network Engineering - jay at impulse.net Impulse Internet Service - http://www.impulse.net/ Your local telephone and internet company - 805 884-6323 - WB6RDV