Weird calls SV8300

[sto933]

Hello there
Customer complains that for a few weeks a guest room number (it's hotel) started to get sporadic calls. It could ring for a second or two, or long enough to answer just to find out that a person was calling another extension.
So we checked all possible forwards - no forwarding to that number, check all DIDs - no DIDS configured for this number too.
System was resetted, we moved this extension to another port on another blade - it still rings.
Looks like PBX uses this extension as "last resort" of call routing.
Is there any configuration for that in SV8300? Or how it is possible to find a root cause for such calls to that extension?

 

[belevedere]

If you have an SMDR program, check that for call traffic to/from that station.

 

[sto933]

Hi belevedere
Yes, we did activated SMDR for this extension (let it call B-etenseion) and found weird calls bouncing between PTT and PABX. There was a call from route 2 to the extension A which is forwarded to route 3(mobile provider Closed User Group). This A number does not exists in CUG so mobile operator bounce it back - calls A-extension then it goes out again on route 3 and this happens few times more. After that extenson B is ringing but mobile provider says no calls for extension B could be done as there is no ext. B in CUG on his side configured!
On SMDR I see a call on route 3 to B extenion as it was answered this time. But there is no possibility to check which number was sent from Mobile operator but I do believe that no B-extension number is send as CUG is only for administrative sets and B-extension is guest room.
From PTT and Mobile operator they send full 4-digits internal number so it couldn\t be wrong DID configuration.
Weirdest case in my experience

 

[sto933]

It's getting more weird.
We checked with Mobile operator and found out that sometimes smb calls to switched-off IP-phones with CFA set. Such calls always go to extension B/
I checked CM50 and CM51 - nothing is configured there. How SV8300 decies that it should ring ext B in case of not-existent number received?

 

[OzzieGeorge]

TLAs (three letter Acronyms) don't help you get answers as people will look at such things as smb calls and think what the h33l is an smb call ! anyway not knowing what that means, why are the IP phones switched off?

 

[sto933]

Hi Ozzie,
Sorry for that, smb=somebody. CFA=CallForwardAll.
ABout IP-phones - who knows? LAN-switch is faulty, power lost, patchcord is plugged out etc. Person calling that IP-phone does not know about switched iit off or not. The point is in that case he does not get busy tone but connects to completely different person.
As I wrote - Mobile Operator returns that call on trunk and guest number is always called.

 

[3racefan3]

If I am am reading this correctly you have an IP phone that is offline and when called the call gets redirected to another station, if that is the case have you looked at Call Forward logout command E606?

 

[sto933]

Hi 3racefan3
Thanks for response.
Not exactly like that, more complicated.
There some IP-phones that use Closed User Group feature from Mobile Operator.
PABX is connected to this operator with PRI and uses local 4-digits numbering.
If person leaves his working place usially he forwards his IP-set to CUG number i.e. his mobile (His mobile set on Mobile Operator side is coupled with his internal number in PABX (via LCR prefix + internal number).
Somebody (it could be an internal extension or DID-call from PTT) calls this forwarded set and goes to a mobile phone.
Some person has set call forwarding all to this CUG without actually being configured in this CUG (never underastimate customer's ignorance) - nobody knows why and how. After some time IP-phone (let it be 2222) is out-of-service.
SO somebody calls this set, let it be 2222, calls goes to mobile LCR+2222.
Mobile operator does not find this number in CUG and bounce this call back to 2222.
After some ping-ponging all such calls goes to a poor hotel guest at extension 1111.

Of course, call forwarding is already disabled on 2222, but the question remains - how could it be that such calls finally land on 1111? I checked commands 50 and 51 - nothing is configured there.


PS: I checked all forwardings with LE6 @STN, no forward is set to extension 1111.