Showing results for 
Search instead for 
Did you mean: 

1861 router - FXS "loop start" won't register with CUCM, but POTS will

Level 1
Level 1

I can’t seem to get any of the FXS ports on my 1861 router to register with CUCM 7.15 via MGCP as “loop start” ports.  If I configure the ports as “POTS” they’ll register with CUCM just fine.

Anyone know why POTS would register and not Loop Start?

I’ve reset MGCP, reset the gateway, reset the specific port, blown away my MGCP config and started fresh, same result.

I’m running IOS 15.0(1)M3. 

2 Replies 2

Rob Huffman
Hall of Fame
Hall of Fame

Hi Jonathan,

From Steven @ Cisco



Hi Rob,

Thanks for the reply.

That bug sure isn't defined very well.  I'm running FXS ports in CUCM 7.15 all over the place without any issue.  It's just on a 1861 router that I'm having to configure as POTS.

The bug makes it sound like FXS will only work as POTS until 8.5, which isn't true.

Thanks for pointed this out, but I'm not convinced this is related to my problem since this issue is only on one router and I'm not using PLAR.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: