An MBG, SIP Trunk, and IVR Challenge

[Spztc1]

Good Afternoon

I am being challenge by our Mitel phone system as the moment and was hoping you could give me some direction.

Senario:
Customer calls main number and reaches our IVR (Call Flow setup in Micollab).  They select prompt 2 for our service menu and then prompt 1 to schedule an appointment.  When hitting prompt 1 there is a "blind transfer" to an outside number.  If their number is not in our system the outside number will transfer the call back to our service department group DID.
When this happens the service department see the CPN number of the SIP PEER Profile and not the customers number that is calling in.

Somewhere in the call the customer number is getting changed to the CPN number.  How can I prevent this from happening so that we see the correct customer Caller ID?

We have a SIP trunk and use a Mitel Border Gateway.  I think the Gateway is causing this issue but I am not sure.

I made some changes to our SIP Peer Profile but that did not fix anything so I put everything back like it was.  I am attaching our SIP profile settings from the MiVoice Business so you can see what they are.

I have reached out to our SIP provider and they are sending the correct Caller ID to us and if the call comes directly to the service department we can see the correct caller ID.  It is only when the call is transfered out and then comes back in that we have a problem.

Any guidance or direction with this is greatly appreciated!

Thank you

[acejavelin]

You will need to capture the packets and look at the invite as it's being sent to the carrier... the callers number should be in the from field and the CPN (billing number) should be in the p-asserted-identity field, if it isn't then the carrier might do some manipulation to make sure it can verify with stir/shaken. In some instances they just put the CPN number in the from field.

[lundah]

Change "Public Calling Party Number Passthrough" in the SIP Peer Profile to Yes, and maybe try changing "Use Diverting Party Number as Calling Party Number" to No.

[Spztc1]

acejavelin!  Thank you! 

I pulled a packet capture and that is exactly what is going on. The "From" number is the CPN and so is the P-Asserted-Identity.
So does this mean I need to get with the Carrier of the offsite number or my SIP trunk Carrier?


Lundah! Thank you! 
I will give that a try and see what happens.

Thanks

[acejavelin]

YOU are sending it incorrectly...

Make sure "Public Calling Party Number Passthrough" and/or "Use Original Calling Party Number If Available" is set to YES in your SIP Peer Profile... Be aware this might directly conflict with "Use Diverting Party Number as Calling Party Number" which you have enabled.

Basically you have 4 options here that you are going to have to mess with to get the correct presentation (assuming the carrier allows it)...

Override From Header with Default CPN
Public Calling Party Number Passthrough
Use Diverting Party Number as Calling Party Number
Use Original Calling Party Number If Available

This may just require some experimentation to get the exact results wanted.

[Spztc1]

Thank you.

I set the Public Calling Party Number Passthrough to yes and the Use Diverting Party Number to No.

This did not make a difference.

I will keep trying. 

What about CPN Restriction?  That is set to no at the moment.  Should I change that to yes?

Thanks

[acejavelin]

CPN Restriction should not matter...

Make some of the changes I mentioned, then look at the invite... when you get a combination that shows the FROM field as the caller and the P-Asserted-Identity field is your main/billing number, you have the right combination and it's up to your carrier to pass that through.

[Spztc1]

acejavelin!

Thank you!

It looks like this combo is working!

Public Calling Party Number Passthrough - YES
Use Diverting Party Number as Calling Party Number - YES

I am still reviewing the packet captures to find the difference but now the customer number is showing as the FROM and P-Asserted-Identity and this is allow the correct number to display.
Before it was the CPN/Main # that was showing as both.

I appreciate all the help and input on this!

Thank you!