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mystic

ANI + Asterlink

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so, I get the whole ANI != CPN, now I'm confused as to who exactly receives ANI information, how and why?

and more specifically, becuase Asterlink is an 800# service does it's users receive ANI info.

my understanding is that 800#'s are billed using WATS (Wide Area Telephone Serivce) and a feasure of inward bound WATS calls is ANI, however I'm not clear as to weather this feature is availible by defualt or wether it's something the customer has to pay for... or whether any of this even applies to a VOIP service such as Asterlink.

does anyone know?

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so, I get the whole ANI != CPN, now I'm confused as to who exactly receives ANI information, how and why?

ANI is a whole mess of things. In the most common scenario, it is derived from the Charge number, which is the number that the billable account for the phone call is registered to. ANI, or whatever you want to call it, is recieved by the terminating switch.

and more specifically, becuase Asterlink is an 800# service does it's users receive ANI info.

No, it recieves CPN with Class of Service, otherwise known as ANI II (ANI II != ANI)

my understanding is that 800#'s are billed using WATS (Wide Area Telephone Serivce) and a feasure of inward bound WATS calls is ANI, however I'm not clear as to weather this feature is availible by defualt or wether it's something the customer has to pay for... or whether any of this even applies to a VOIP service such as Asterlink.

WATS has been dead for a while, went the way of the crossbar. 800#s, for the most part, are just like regular numbers now in the routing sense, there is some IXC magic going on, but nothing like WATS was. '

Not sure if this answers your question.

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VoIP doesn't have a charge number. It's either going to be the charge number from when it's converted from PSTN dialing out. Or no charge number at all. There for no "real time" ANI with VoIP.

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WATS has been dead for a while, went the way of the crossbar. 800#s, for the most part, are just like regular numbers now in the routing sense, there is some IXC magic going on, but nothing like WATS was. '

interesting, then someone should update this... http://en.wikipedia.org/wiki/Automatic_Number_Identification

Also, I did alittle more research and answered a few of my own questions:

800#'s when set up through IXC's such as sprint or MCI (also SBC(?)) can receive Real-time ANI (why dont they just call it RANI) over the D-channel of an ISDN line connected to the PBX. However according to MCI's Advanced Toll Free Service there is another way of receiving the ANI information, anyone know what this is, is it some form of in-band signaling? (thier sales department wasnt there when I called).

So visualy (i like pictures) it goes like this:

you (207-555-5555) => (DTMF) 18004444444 => PSTN => LEC => (SS7) Charge Number = 2075555555 => IXC => (ISDN D-Channel) ANI = 2075555555 => 18004444444

also 18004444444 reads back your CPN not ChN so they must be also getting the CPN through in-band singnaling.

am I right here?

Edited by mystic
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also 18004444444 reads back your CPN not ChN so they must be also getting the CPN through in-band singnaling.

am I right here?

Are you sure about this?

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also 18004444444 reads back your CPN not ChN so they must be also getting the CPN through in-band singnaling.

am I right here?

Are you sure about this?

oh, hey what do you know, it does read back your ChN, or atleast it did when I tried to spoof my CPN. I read somewhere that it didn't, oh well

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VoIP doesn't have a charge number.  It's either going to be the charge number from when it's converted from PSTN dialing out.  Or no charge number at all.  There for no "real time" ANI with VoIP.

Well, as soon as it his SS7, some charge number is there. It's usually your VoIP provider though.

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VoIP doesn't have a charge number.  It's either going to be the charge number from when it's converted from PSTN dialing out.  Or no charge number at all.  There for no "real time" ANI with VoIP.

I think this should be clarified - current popular voip signaling protocols (SIP, IAX) don't have a field for charge number like SS7 does. There's nothing, however, stopping anyone from implementing a signaling protocol that matches SS7's number delivery fields. (Does H.323 do this?)

Also, I did alittle more research and answered a few of my own questions:

800#'s when set up through IXC's such as sprint or MCI (also SBC(?)) can receive Real-time ANI (why dont they just call it RANI) over the D-channel of an ISDN line connected to the PBX. However according to MCI's Advanced Toll Free Service there is another way of receiving the ANI information, anyone know what this is,  is it some form of in-band signaling? (thier sales department wasnt there when I called).

So visualy (i like pictures) it goes like this:

you (207-555-5555) => (DTMF) 18004444444 => PSTN => LEC => (SS7) Charge Number = 2075555555 => IXC => (ISDN D-Channel) ANI = 2075555555 => 18004444444

also 18004444444 reads back your CPN not ChN so they must be also getting the CPN through in-band singnaling.

am I right here?

"Real-Time ANI delivery" simply means that the contents of the charge number field are delivered to your equipment during call set-up rather than remaining a mystery until it shows up on your bill at the end of the month.

In the SS7 ISUP IAM (Initial Address Message), there are the following fields for number delivery (this is not a complete list, but nonessential parameters of the number fields are being left out for the sake of simplicity):

• Called Party Number

• Charge Number

• Originating Line Information Parameter

• Calling Party Number

• Original Called Number

• Redirecting Number

Called Party Number is the only mandatory field; the rest are optional. Originating Line Information Parameter is the field which contains the class of service digits (also known as ANI II). So, assuming you call 800-444-4444 from a wireline telephone whose number is 311-555-2368, and assuming that the terminus of the toll-free number is on a trunk served directly by the interexchange carrier handling the tollfree call (thus avoiding the extra complication of translating the tollfree number back into a regular POTS number), the fields are likely to be populated as follows for the majority of the links in the call setup:

• Called Party Number - +18004444444

• Charge Number - +13115552368

• Originating Line Information Parameter - 00 (among other things)

• Calling Party Number +13115552368

• Original Called Number - +18004444444

• Redirecting Number

The D-channel of the ISDN trunk handling the last link of the call before it hits the customer's equipment can be provisioned to receive either charge number or calling party number for the purposes of real-time ANI delivery. There is also "Dialed Number Identification Service" which delivers the original called number to the customer so that the same equipment and trunkgroups can be used to handle calls to different numbers.

If the terminating end of the connection is not an ISDN trunk (say either a channelized DS1 or a POTS line), real-time ANI delivery can be handled either by using good old caller ID or by doing some variety of in-band signaling (MF or DTMF) to the called party's equipment immediately after the called end supervises. Dialed Number Identification Service may also work in this manner on non-ISDN connections.

(the above may not be 100% accurate, but I believe it to be mostly correct based on all the data that's available to me)

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I did some experimentation, it looks like Asterlink DOES send the Charge Number as caller ID info to your Asterisk box:

first I tried calling it from a blocked number, it showed up in caller id.

then I tried spoofing my CPN to it's self, the CLI showed up as: 17038576225 (same number 8004444444 gives)

then I just simply called my Asterlink # to it's self and got 17038576225 as the caller id again.

if anyone knows any better way of testing let me know, but I'm pretty sure this means that Asterlink sends the ChN as caller ID to your * box

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So when you block your number (*67), and dial 1800-444-4444, it still gives you your real number somehow, is this because it recieves CPN?, and nomatter what it gets, how come *69 wont return calls to blocked numbers....everyone has caller id now and don't even need the service unless it would return blocked calls

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So when you block your number (*67), and dial 1800-444-4444, it still gives you your real number somehow, is this because it recieves CPN?, and nomatter what it gets, how come *69 wont return calls to blocked numbers....everyone has caller id now and don't even need the service unless it would return blocked calls

800444-4444 (MCI) - gives you CPN when it receives "what it thinks as a valid number" - try spoofing a 777-777-7777 number (or 8005551212, etc. - something that it flags as "not valid", and you'll see it will read back the RT-ANI.

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I just called it up sending completely different fields for my CPN and charge number/billing telephone number/ani/whatever the hell you crazy whippersnappers are calling it these days, and it read back my BTN, even with my caller-id blocked. If I'm not mistaken, the way it used to work is that it'd just read back your CPN unless you sent a caller-id privacy bit.

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Let me clear this whole thing up:

1-800-444-4444 is a weird ANAC. The way it works is it goes for your Caller-ID, but if your Caller-ID is unavailable (like when you press *67), it will instead go for your Charge Number (BTN if you must call it that). The ANAC will NEVER read your CPN, and there IS a difference between Caller-ID and CPN; it's important to remember that.

It doesn't stop there though. If the Caller-ID it receives is a number that doesn't "seem" like a valid telephone number, it will still opt for the Charge Number. So if you were to spoof a Caller-ID of, say, 666-123-4567, the ANAC would ignore that and read back the Charge Number instead. I forget all the details of what numbers it will and will not read, but I'm pretty sure the NPA, at the very least, needs to be valid. I also think that numbers less or more than 10 digits will also be ignored. It's been a while since I've played with this, so if you have a way to spoof Caller-ID with a different Charge Number, experiment with different sets of numbers and you'll see what I'm talking about. After learning all of this, what would you say if I told you that 1-800-444-4444 is used by many technicians to ANAC lines they're working on?

The person to first figure this out years ago on the socal was Doug. He used a VoIP provider that passed a different Charge Number than his CPN and Caller-ID. When he dialed *67, 1-800-444-4444, the system, to his surprise, read back his Charge Number. Months later, another socal attendee, who many us know well, figured out the same thing while playing around with a bunch of prepaid phone cards. One of these cards also passed its own unique Charge Number, while the CPN and Caller-ID (when it's available) were the number you were calling from. Sure enough, pressing *67 before calling the phone card's number and initiating a call to the 1-800-444-4444 ANAC would cause the card's Charge Number to be read back, rather than his own home telephone number. So credit goes to these two people for figuring out how strange this ANAC works.

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