DIALSTATUS = BUSY and HANGUPCAUSE = 17

Hi All,

     I am receiving  this message "all circuit are busy now", and upon further investigation i saw in logs i saw this error on the logs "DIALSTATUS = BUSY and HANGUPCAUSE = 17". 

Note: this issue is on and off but we are getting it around 300 times a day, so it is very frequent and becoming and alarming issue.(big system Xorcom appliance around 280 extension)

version info:
we are using Elastix 2.2.0-22
Freepbx: 2.8.1.4-12
Asterisk: 1.8.9.1-1

Thank you for any helpful suggestions.

Subscriber engaged. If this is ISDN, that will be the precise diagnostic. If it is SIP, there may be more than one SIP status code that maps to subscriber engaged,

Please note this is not a fault, unless there is some reason for you to believe that it is being used incorrectly.

Is it because the user is busy, or is it because the PRI used could not connect the call.

Google “isdn cause codes” for the meanings of the various values. The official meaning is that the subscriber is busy. Although I don’t use PRI interfaces, you can configure Asterisk to display the contents of the signalling messages.