Understanding ANI x CPN with VoIP

Original .txt

// Understanding ANI & CPN with VoIP
// by Doug Brickner
// http://www.oldskoolphreak.com

ANI (Automatic Number Identification) & CPN (Calling
Party Number) has always been very confusing.
Especially now with VoIP (Voice Over IP) telephones.
This article will explain to you the difference of
what Vonage, VoicePulse and a few other VoIP providers
send as ANI & CPN/Caller ID when using their Caller ID
block feature.

When you place a call the switch logs the time of
call, the number you're calling from and the number
you're calling to. If the switch is SS7 compatible
(which 99.99% of switches are), then the switch sends
your ANI and CPN along in a packet of data. The ANI
is the number you called from, and so is the CPN
(assuming you're using a regular telephone line).
If you're using a PBX/PaBX system with trunks then
you may have to specify your CPN on your outgoing
calls, as DOD trunks do not have phone numbers
associated with them since they are
Direct -Outwards - Dialing, in other words, the
DOD is specifically meant to make calls, not receive

Vonage does this almost like a regular land line.
Your CPN and Caller ID are sent fine. If you use *67
they send a private tag but the CPN is still sent.
But the ANI is always going to be some 10 digit number
that belongs to Vonage. This number is just some disconnected
number when you call it. This is because realtime ANI
doesn't really work with VoIP because VoIP isn't exactly
a real telephone line. So the CPN is "spoofed" as the
Vonage customer's VoIP telephone number.

Here is a chart of what your ANI/CPN/CID is like with Vonage,
VoicePulse, and Packet8 when using the Caller ID block feature.

VONAGE Blocked/*67
973-954-4049 ANI
Your Vonage Number CPN
"PRIVATE" Caller ID Box

VONAGE Unblocked
973-954-4049 ANI
Your Vonage Number CPN
Your Vonage Number Caller ID Box

VOICEPULSE Blocked/*67
646-619-5149 ANI
212-400-7400 CPN
"PRIVATE" Caller ID Box

VOICEPULSE Unblocked/*82
646-619-5149 ANI
Your VoicePulse Number CPN
Your VoicePulse Number Caller ID Box

PACKET8 Blocked
040-361-6210 CPN
040-361-6210 Caller ID Box

PACKET8 Unblocked
Your Packet8 Number CPN
Your Packet8 Number Caller ID Box

When you have your Caller ID blocked, VoicePulse
sets a private tag but also changes your CPN to
a 212-400 number that they own which happens to
be disconnected. When Caller ID is unblocked
(or you use *82) VoicePulse will send the proper
CPN as your VoicePulse number allowing it to be
sent to Caller ID boxes. VoicePulse's and Vonage's
realtime ANI is also some other disconnected number.

Why VoicePulse changes your CPN to their 212 number
AND sends a private tag for caller ID? I have no idea.
Maybe it's because they believe sending Private isn't enough,
they also have to send a fake CPN so nobody can get back to you.

VoicePulse is a good way to go. Because when you block
your number, all people will get is some disconnected
numbers. Now can that get traced back to you? Of
course it can. They can find out it's VoicePulse and
VoicePulse can find out easily it's you. That's why you
should never do anything too stupid.

I tested all of this is with ANACs.
(Even though it says ANI. It IS reading the CPN)

Sorry, I can't give you any real time ANACs. The ones
that I use are toll free that don't require any kind of
password; those are hard to find.

Speaking of ANACs, you should also know that 1-800-444-4444
does NOT read CPN. It reads Caller ID then if Caller ID
is blocked it reads the ANI. Now I know you're
probably thinking What the hell?! CPN is Caller ID
you n00b! Well yes, Caller ID is generated by CPN.
However All 800-444-4444 does is look for the caller ID
information. If it receives Private or any kind of
bullshit kind of number it therefore goes and grabs
the real time ANI. Why it does this. I don't know.

The perfect way to test this is with Vonage.
I explained how Vonage's realtime is a 973-954-4049
number and Vonage's CPN is ALWAYS going to be your Vonage
number. Well if your *67-1-800-444-4444 with Vonage. You'll
notice it looked for the Caller ID, but of course it was
private so therefore it grabbed your Realtime which is the
973-954-4049 number instead of your Vonage number.

Even though if I call *67-1-866-MY-ANI-IS with Vonage
it will still read my CPN. Another way is to test this
with certain kinds of calling cards, knowing what they
pass for ANI, CPN, and if they block Caller ID or not.

You can also always use a soft phone application with an IAX
provider so you can spoof any CPN you would like. It's also
good to find a good open access VoIP provider that doesn't
have a real time ANI at all either.

It will make you anonymous...
but everything can still be traced.

Created by: kFuQ, Last modification: Sun 02 of Oct, 2005 (14:18 UTC)
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