I have Cisco UCM 8.6 and Cisco 2911 voice gateway connected in my office to which we have more than 16 PSTN line connected to. We are facing an issue with the voice gateway since a couple of weeks as it shows the call status "No DSP" and it occupies some of the ports for long time till reboot the gateway/clear the calls. I have attached a screenshot herewith for clear visibility.
Can anyone please advise how to fix this? Thanks for reading this post and your time.