Limited PSTN calls on CUCM 8.6

Unanswered Question


I am facing an issue with maximum simultaneous PSTN calls in our office. We are currently running CUCM 8.6 with VGW 2801 router; 8 FXO lines. All lines are working fine. At any given time, I am able to use only max 5 lines for PSTN calls (incoming and outgoing included). The 6th call onwards gives a busy tone. Attached is the VGW config.

Any advice is appreciated.



  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Gajanan Pande Wed, 11/30/2011 - 00:49
User Badges:
  • Cisco Employee,

About the 6th port/line onwards, will it always be the same port, blocking the call or randomly the 6th, 7th & 8th calls ( no matter which port it goes thru ) are dropped ?

Did you collect any debug outputs ?

D_Lebedev Wed, 11/30/2011 - 01:51
User Badges:

Please,provide screen from Gateway Config_MGCP from your CM.

Also please pay attention to your Route groups...

Chris Deren Wed, 11/30/2011 - 06:42
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,
  • Cisco Designated VIP,

    2017 IP Telephony, Contact Center, Unified Communications

Have you attempted to reset the port?

Can you tried changing the trunk-group order to move the port to be the last one used?

Is this an FXO or FXS/DID line, if FOX what happens when you call the number associated with this line?



This Discussion