[Asterisk-Users] Blocking the 'Do Not Call" List

[John Todd]

At 12:22 PM -0400 on 8/10/04, drodden wrote:
>Anybody have any experience with blocking numbers in the U.S's Do Not
>Call list?
>
>We have a customer that will be getting their own Asterisk server from
>us, and they want it to be check outbound numbers against the do not
>call list; this is for a backup, in case there's a slip up and one of
>their people try to dial somebody on the do not call list.
>
>The list has millions of numbers, and I don't think the extensions.conf
>file could handle me listing all million+ phone numbers and making it
>play a sound like "That number is on the do not call list", and then
>creating a _NXXNXXNXXX extension at the very bottom. The list would take
>up all it's memory. Anybody have a more elegant solution? Maybe an AGI
>script to match the outbound phone number against a column in a table in
>a MySQL database? Is there something similar already written that I can
>just modify?
>
>I know one of our T1 PRI Providers support this feature, but I don't
>want to block the list from all of our customers, just this one
>customer. Maybe they can do source+destination based blocking. I'd still
>prefer it be done through Asterisk. Suggestions?

This actually sounds like a problem that is asking for an ENUM 
solution.  <gasp>  I think that DNSSEC, some IP filters, plus forcing 
telemarketers to subscribe to the lookup service would go a long way 
to solving this problem and moving the burden from your shoulders 
onto the shoulders of the US guv'mint, which could probably fairly 
easily fund something like this (all open source).  Some enterprising 
firm should offer that service (hello to all my friends at Neustar's 
managed ENUM service!)

The trick here is that I'm sure you're not the only one asking for 
these numbers.  I'll bet there are hundreds of firms asking for these 
numbers.  If the FCC hands out a "database" of all those 
destinations, that might be used in a Bad way, since then copies will 
undoubtedly find their way into the hands of telemarketers.  DNS 
queries can be measured from individual resolvers, and anyone 
"farming" the DNS tree can be suitably discovered and punished, 
unlike a CD-ROM of data that vanishes into the swarming underground 
of tele-sleeze.

Regardless of the advantages or disadvantages of the data escaping 
into the wild, the other advantage that ENUM would have here would be 
that it would be dynamic; the FCC (or ITC, or whoever keeps that 
database) would be able to dynamically update the DNS tree and then 
within 10 minutes, the new entries would appear and everyone would be 
using them.

One might argue that an XML query using AGI or a custom app might 
have the same benefit, but ENUM/DNS seems to work just as well and it 
has some advantages that a standard database doesn't for this type of 
simple-result query.

JT