Telco charges a calls with 0 duration based from the CDR

[ccg-collab1]

Hi All,

Some calls are being charge by the Telco especially on mobile number but these calls has 0 duration on the CDR but reflected with 1 second or more on the telco actual invoice/billing report. May we know if what causing this and if there is some adjustment that needs to be done on CUCM/Gateway side.

I observed that not all with 0 duration calls are being charge but only the call with cause value 393216 (I understand that this cause value is due to split call or made via transfer)

The setup is:

IP Phone > CUCM > MGCP Gateway > PRI 

Appreciate your response.

[ccg-collab1]

Additionally, these calls with 0 duration calls are being sent to the billing server which is consistent - it means CUCM is properly sending the data to billing server with the correct data. But in Telco side these calls has a duration.

Example:

CUCM CDR: Call to mobile has 0 duration with date time connect = 0

Call Billing Server: Also 0 duration

Telco actual invoice/billing report: 1 or more second duration.

What would be the possible cause of this?

[Georgios Fotiadis]

Does this happen with all zero-duration calls or with some of them? Can you ask the users what calls those were and if they remember their outcome (for eg. they were hearing ring but noone picked-up)? You are sure they are exact match with Telco CDR, right? Just asking in case there is a timezone mix.

Also, last but not least, they could be unsuccessful SIP calls on your side where CUCM sees them as not connected, while some IVR has picked-up on the other side.

[ccg-collab1]

Hi Georgios,

This happens only on some calls and not all with zero duration calls. These calls are not SIP but via E1 PSTN.

[Georgios Fotiadis]

Did you try to talk to any of your users? Ask them what these calls were and what was the outcome of dialing to that number.