Showing results for 
Search instead for 
Did you mean: 



Hi all,

I´ve got a problem understanding T1-CAS E&M and ANI/DNIS. We don´t have T1s in Germany so I wonder what FeaterGroup to use to have incoming and outgoing ANI/DNIS as we have with PRI.

As far as I understand, I always will have incoming DNIS from my CO for DID. But what about ANI?

For example: Can I use FGB and tell my Gateway how many of the incoming digits to interpret as ANI and to interpret the rest as DNIS? The same for outgoing calls?

I´ve read something about cas-custom commands? Would that be the way to do that?

In the web I find documents stating that EANA will not support incoming ANI. Is that right? I will not have the chance to try it out.

As you perhaps recognized, I need to prepare for a lab - but how to pass it if I don´t understand your technologies we do not have in Europe...

Thank you for your help guys.

3 Replies 3

Daniel Baum
Cisco Employee
Cisco Employee

With T1 CAS E&M Feature Group B (FGB) from the telco and on the router/gateway, this feature group does not support ANI delivery to the PSTN. ANI (autmotic number identifier) is provided by the PSTN to the

called destination.

To correct this issue and have the number changed on this T1 E&M "FGB" circuit, you must do 1 of 3

things to remedy:

1-Telephone company changes the ANI to the corrected number

2-(or) upgrade this long distance circuit to T1 PRI

3-(or) change the T1 CAS E&M feature group to "FGD" or better known as or "Feature Group D" and

reconfigure the router to support "FGD".

Here is the explanation of what "FGD" provides for you:

On Cisco implementation, signaling type "E&M-FGD" is taking the role of carrier.

For those who need to send ANI for outgoing calls using FGD, Cisco implemented FGD-EANA for this

purpose, which use TWO winks methodology.

EANA is a one stage dialing that contains two fields. The field transmitted first contains the call

customer?s identification number (ANI) that is used for billing purposes. Only MF pulsing is used

for ANI field.

The second field contains the called telephone number (DNIS). Either MF or DTMF pulsing can be used

for this field. When DTMF is used, there is no DNIS out-pulsed from BOC point of view, DNIS is

collected via voice band. The two fields are identified by special delimiter Key Pulse "KP" and

Start "ST", two special MF tones. When router received both ANI and DNIS (in MF mode), it sends out

a wink acknowledgment to BOC and from that point on the call is considered established.

FGD has the following variations:

- Originating protocols:

Exchange Access North American (EANA)

Exchange Access International (EAIN)

Operator Services (OS)

- Terminating protocol


Hi Dan,

thank you for your answer.

When you say "Cisco is taking the role of carrier", what does that mean? Is it comparable to master/slave in PRI between Router/CO? If so, does it mean, I have to tell my Provider that I need to be "carrier"?

You say EANA provides ANI/DNIS for outgoing calls, does it also receive both? I found the following document, under "Restrictions" it says, EANA does not provide incoming ANI?

Again, thank you for your help!

P.S: Why can´t we all use E1 PRI. ;-)


The router is sending ANI out to the carrier to forward rather than ANI originating at the carrier to forward.

My wording could have been more clear.

There is no need to inform the telco that you are acting as the carrier. That was my wording saying that your sending ANI, but, simply inform the telco that you want to enable FGD and that you will be forwarding ANI.

Your correct on the incoming ANI, not provided.

Hope this helps.


Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Recognize Your Peers