atcomsystems.ca/forum Forums General General Telephone & Systems Information DID and DNIS

Not to argue.

I will try to make this simple for Kevhawk13.

DID is the digits that come in as RBF stated earlier. When someone calls 918-555-1212 then the carrier switch is set to send X digits. in this case we will say 4. It sends 1212 to the phone switch on the customer location. The phone switch then has a routing table that says digits 1212 goes to extension 323 or what ever your system is set for.

ANI. on a e&m T1 trunk is the callerid number only information. This is why when a carrier tells you that he is sending *DNIS*ANI* or *ANI*DNIS* this means it will send *1212*4055551212* or *4055551212*1212* This is so that you will get callerid number. Callerid name is not on E&M wink start trunks.

Having setup many of these in the DMS class 5 phone swithes on T1. I have not ever tested this on an analog DID though. Around Oklahoma they are not very common.

Several people consider the DID and ANI on a PRI as well. However it is the basically the same thing it is not exactly the same.

On a PRI the Call information is sent over a D channel. This type of service does support Callerid Name and Number. However it is not considered ANI on this type of service. But the DID portion is still considered DID just sent differnet format.

Hope this helps.

Brian

"On a PRI the Call information is sent over a D channel. This type of service does support Callerid Name and Number."

True it is sent over a D channel. I install NI2 protocol PRIs almost everyday that do deliver name and number and I receive DNIS digits also. They are treated as DIDs. DNIS delivered on an analog T1 is considered ANI to most PBXs I have been associated with.

You can have DNIS on PRIs without DID numbers but they still must be treated as DIDs and translated.

Sorry RBF.

Typed the wrong acronym. You are correct ANI. I have edited my post.

Thought the right one typed the wrong one.

Brian, that pretty much sums it up. DID digits match the last digits (2-7 digits) dialed exactly, where DNIS digits can be whatever is requested of the carrier. For example, the customer's sales department's local number is 578-832-8700. When local callers dial this number, 8700 is sent as DID digits.

When someone from outside of the area dials the company's toll-free number (800-832-8700), the long distance carrier doesn't simply send "8700" again. The customer needs to be able to track the calls on an originating basis (local or out-of-area).

With DNIS, calls to the toll-free 8700 number from San Diego might send 9991 as DNIS digits; Chicago would be 9992 and so on. Different DNIS digits are being sent based upon the dialed number to allow the advertiser to track the originating area (and TV channel) generating the sales lead.

The true answer is that DID digits are fixed digits sent that are tied to the dialed local number. DNIS digits can be manipulated by interexchange carriers so that they don't have to match the dialed number at all. DNIS is the way of the times since it offers much more flexibility.

You can send me "5974481" and my PBX automatically knows that you really need extension "25".

That is true ed.

Just for him to keep in mind that in most cases a 800 number is pointed to a local DID number.

Here is another example for him.

Lets say you have 2 number coming in 4056394115 and 4057214115. Your switch is setup for 4 digits. This would mean you would have 2 phone numbers setup to send 4115 to your switch.

In this case you would request the carrier to send different digits to you for one of the phone numbers.

You would leave 4056394115 as a DID sending 4115.

You would request that 4057214115 send DNIS 9981 to your switch.

This way your switch would know that one number routes to one extension and the other number routes to another extension.

Or in what ed is saying you could set both numbers to route to the same extension. But the 800 number is pointed at 4056394115 and the main phone number to the business is 4057214115. This way you could tell how many 800 calls you get verse how many local calls you get.

Basically as Ed stated above. They both work the same. Telco sends x DID digits to phone system. Telco sends X DNIS digits to phone system.

The only real difference is if the telco is converting the sending digits or just sending the last X number of digits of the phone number.

Brian.

Gentlemen,
Thanks for the info!

"True it is sent over a D channel. I install NI2 protocol PRIs almost everyday that do deliver name and number and I receive DNIS digits also. They are treated as DIDs. DNIS delivered on an analog T1 is considered ANI to most PBXs I have been associated with.


So RBF.....

The DNIS on PRI channel D is sent over NI2 is treated as DID while DNIS on T1 is considered ANI by the PBX.

And you guys think the GCs talk funny. :confused:

Don't you have a computer to reboot? :rofl:

Actually, I think I need a beer or two after reading this thread. It does answer some questions I've had on DID, but never asked. Thanks everyone for that. :-)

The beer or two thing has always worked for me.