Cisco IP Communicator 8.6.5 Release Notes

Overview

Cisco IP Communicator (IP Communicator) is a softphone application that provides voice and video calling capabilities directly from a Windows desktop. Version 8.6.5 introduces a series of enhancements, bug fixes, and security updates that improve reliability, performance, and user experience. This document summarizes the key changes and provides guidance for administrators and endusers who are upgrading from earlier releases.

New Features

• Improved Call Quality Controls Added adaptive jitter buffer settings that automatically adjust based on network conditions.
• Enhanced Video Support Support for 1080p video resolution and AVPF (Audio/Video Profile with Feedback) for better synchronization.
• Integrated Call Recording New API that enables call recording through Cisco Unified Communications Manager (CUCM) without thirdparty tools.
• Modern UI Refresh Updated icons, highDPI scaling, and a simplified contact list view.
• MultiAccount Management Ability to configure and switch between multiple CUCM accounts from a single client.

Bug Fixes

General Stability

• Resolved a crash that occurred when a user attempted to place a call while the network adapter was temporarily disconnected.
• Fixed memory leak in the video rendering engine that could cause the application to consume excessive RAM over long sessions.

Call Handling

• Corrected an issue where DTMF tones sent during a conference call were not received by remote participants.
• Addressed a bug that prevented call hold/retrieve when the user changed the audio device during an active call.

Audio/Video

• Eliminated audio echo in scenarios involving Bluetooth headsets on Windows 10/11.
• Fixed video freeze when switching between frontfacing and rearfacing cameras on laptops with dual camera setups.

Compatibility

• Updated the installer to work correctly with Windows 11 version 22H2.
• Improved interoperability with Cisco Unified Presence Server 10.5.

Security Enhancements

• TLS 1.2 enforcement for all SIP signaling traffic; TLS 1.0 and 1.1 are disabled by default.
• Added support for SHA256 certificates in mutual TLS authentication.
• Implemented a hardened credential storage mechanism that encrypts saved passwords using Windows Data Protection API (DPAPI).
• Mitigated CVE20251234 by addressing a buffer overflow in the SIP header parser.

Installation and Upgrade

The 8.6.5 release is delivered as an MSI package that can be deployed via Group Policy, SCCM, or manually on individual workstations. The installer performs a silent upgrade when a previous version (8.5.x8.6.4) is detected.

Prerequisites

• Microsoft Windows 10 (1809 or later) or Windows 11.
• .NET Framework 4.8 or later.
• CUCM version 11.5 or newer with SIP TLS enabled.
• Administrative rights on the target computer.

Upgrade Steps

1. Back up the existing IPCommunicator.cfg configuration file located in %AppData%\Cisco\IPCommunicator.
2. Run the MSI with the /quiet switch for a silent install, or use the GUI installer for interactive deployment.
3. After installation, launch IP Communicator and verify that the version number displayed on the About dialog reads 8.6.5.
4. If you performed a manual backup, restore the configuration file to the same location.

Known Issues

• When using QoS policies that limit UDP port 5060 traffic, incoming SIP INVITE messages may be delayed. Workaround: add an exception for UDP ports 5060 and 5061.
• Screen sharing on Windows 11 may not appear to the remote party if the "Graphics Capture API" is disabled. Enable the feature via Settings Gaming Captures.
• Clients with thirdparty antivirus software that block unsigned DLLs can experience startup failures. Whitelist the installation directory (C:\Program Files\Cisco\IPCommunicator).

Compatibility Matrix

Support Information

For assistance with installation, configuration, or troubleshooting, contact your Cisco Technical Assistance Center (TAC) or open a case through Cisco Smart Net Total Care. The following resources are also available:

• Release Notes PDF downloadable from Cisco.com.
• Administrator Guide Chapter Deploying IP Communicator.
• Community Forums community.cisco.com