"Unknown" Value on CDR Calling Party Number Field

[fdharmawan]

Hi Guys,

Recently I've been digging into some call records to generate some reports. But, on callingPartyNumber from CDR records, some of the values are "Unknown". Is this some kind of bug or it's a missing info received by the CM? My CM is 11.5.

Thanks.

[Andrew Skelly · Accepted solution]

Are these calls that originated from your CM or are these calls that originated outside of your network (i.e. inbound from the PSTN)?  If inbound to you from the PSTN most likely these are calls where the number was blocked by the sender (anonymous, unpublished/unlisted, etc)

[fdharmawan]

Hi Andrew,

Maybe, that's what I'm trying to figure out. The destination is always internal phone extension. So I guess it's either from another extension or from external source. With your explanation, I think it makes sense.

Do you have any idea where this blocking happens? I mean on ISP side or from the caller's side? Thanks.

[piyush aghera]

Callers may have requested their ISPs to block their identity.

[Andrew Skelly]

Ultimately it is the originating telco that is blocking the caller ID but it is at the discretion of the originating caller.  The caller may have their numbers unlisted or unpublished, which means that every call they make their number will not show on the far end and the name may show up as Blocked, Anonymous, etc.  Conversely the originating caller may have their phone number listed or published but chose to block it on that specific call.  You can test this yourself by making a call from your cell phone to your Cisco desk phone.  Just dial *67 then your DID number from your cell phone (*67 blocks your caller ID).  So from your cell phone it would look like you dialed *6712125551212.  On your CDR you can look to see what comes up as the originating caller information.