The earliest recollection of this bug is traced back to PAN-OS 11.1.10-h4 - December 01, 2025. This bug is fixed in PAN-OS versions 12.1.3, 11.2.10, 11.1.10-h4, 11.1.6-h17, 11.1.11. Fixed an issue where the NAT IP address pool was exhausted, which led to intermittent connectivity issues with call applications and outbound call failures. This occurred due to the firewall not properly releasing NAT dynamic ports back to the address pool. For more information: https://docs.paloaltonetworks.com/ngfw/release-notes/12-1/pan-os-12-1-3-known-and-addressed-issues/pan-os-12-1-3-addressed-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-10-known-and-addressed-issues/pan-os-11-1-10-h4-addressed-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-11-known-and-addressed-issues/pan-os-11-1-11-addressed-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-6-known-and-addressed-issues/pan-os-11-1-6-h17-addressed-issues https://docs.paloaltonetworks.com/pan-os/11-2/pan-os-release-notes/pan-os-11-2-10-known-and-addressed-issues/pan-os-11-2-10-addressed-issues