What's new in AudioCodes Generic SIP IP Phones and Gateways devices?

The 425HD is an advanced, mid-range business IP phone for office workers and common area users, featuring a large multi-lingual 3.5” color non-touch display and 8 programmable multi-function keys. The 445HD is a high-end IP phone with an integrated sidecar, providing additional programmable keys for enhanced functionality. The C450HD is a versatile IP phone with optional expansion, supporting advanced connectivity options and a sleek design. These devices ensure seamless and productive communication for various business environments.

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January 1, 2026
Version 3.5.4.44
  • 445HD
  • 425HD
  • C450HD

Supported Models:

Release Notes

SIP Environment Compatibility Notes:

  • Microsoft SIP Gateway: This version is under final review by Microsoft to replace the current GA release. While Microsoft certification is pending, AudioCodes has approved it for use. OVOC customers may obtain the firmware directly from AudioCodes to begin deployment immediately.
  • Cisco Webex: Cisco approval is expected by February 2026. Until then, version 3.5.2.32 remains the officially supported release for Webex environments.
  • Zoom: Version 3.5.4.44 is not released for Zoom. AudioCodes SIP phones 445HD and C450HD in Zoom environments should continue using version 3.5.1.89.

Main Features In This Release:

(For detailed configuration instructions of each of the features, please refer to the version Release Notes).

Reboot menu option moved from Admin menu to Settings menu

Reboot menu option moved from Admin menu to Settings menu to allow the non-administrative users to reboot the phone.

Exclude ‘feature code dialing’ from Call Log

Feature code dialing is a PBX mechanism used for special functions (e.g., follow me, Call 
Forwarding, Do Not Disturb, etc.) rather than for regular call dialing. 
Feature codes typically include identifiable prefixes and/or suffixes such as #123#, *678*, *#123456*#, or other administrator-defined patterns.

Cisco WebeX and Broadsoft Environment - Call Log Integration based on XSI protocol

The XSI Call Log enables users to view and manage detailed call history directly within the IP 
Phone interface. This integrated functionality provides a centralized record of inbound, 
outbound, and missed calls associated with the user's extension.

Support redundancy failback when DNS resolution of the SIP proxy server’s FQDN returns a 
different IP address.

Added new function key type Speed_Dial_BLF

To allow presence per functional key

Ability to disable the presence SUBSCRIBE message

For Speed_Dial functional key type only

Resend SUBSCRIBE message if received 404 response

Ability to disable the presence SUBSCRIBE message

For Call Log lists

INVITE message configuration added

Conference call configuration for Vodafone environment

Special XSI configuration for Vodafone environment 

Ability to disable/enable NTP queries for public NTP servers

Display caller ID from P-Asserted identity header instead of From header in incoming call

Firmware header download method for HTTP server to avoid downloading entire file if device version is the same as on the server

Ability to disable New Call Softkey in Incoming Call screen

Prevent SIP UNSUBSCRIBE on VoIP Reload upon failover/failback

Release Notes

November 12, 2025
Version 3.5.2.32 - Cisco Webex

Supported Models:

Key Notes:

  • To enable connection of your IP phone to the Cisco Webex environment, please ensure it is updated to version 3.5.2.32. This build integrates Identrust trusted CA certificates, enhancing compatibility and security.
  • Important: This version is only for Cisco Webex environments. For all other environments, continue using:
    • 3.5.1.75 (general use)
    • 3.5.1.75.5 (general use - specifically for 425HD)

About Cisco Webex Calling

Cisco Webex Calling is a secure, enterprise-grade cloud calling and collaboration solution optimized for businesses. It includes centralized administration and device management. AudioCodes IP Phones are fully interoperable with Cisco Webex Calling and support essential business calling capabilities.
Additional Resources:

August 1, 2025
Version 3.5.1.89 - Zoom

Supported Models:

Key Notes:

  • Important: This version is only for Zoom environment. For all other environments, continue using version 3.5.1.75.

October 30, 2025
Version 3.5.1.75.5 - 425HD only

Supported Models:

Key Notes:

  • Due to several field-reported issues related to the 425HD model, AudioCodes is releasing an updated firmware version specifically for this model: 3.5.1.75.5.
  • This version is based on the current release (3.5.1.75) and includes fixes for the following issues:
    • IPPUC-11067 – [425HD] In certain cases, audio may be lost after prolonged idle time without rebooting the device.
    • IPPUC-11113 – [425HD] Following specific calling scenarios, pressing the ‘Speaker’ hard key to initiate a call may result in a short beep, which is actually part of an endless busy tone. Rebooting the phone resolve the issue.
    • IPPUC-11112 – [425HD] When the volume is lowered to its minimum during idle, pressing the ‘Speaker’ hard key produces no tone. Increasing the volume resolves the issue. 

 

May 6, 2025
Version 3.5.1.75
  • 445HD
  • 425HD
  • C450HD

Supported Models:

Release Notes

Main Features In This Release:

SCEP: Certificate Signing Request Enhancements

Includes adding retry attempts to the certificate enrolment and renewal process and supporting Subject Alternative Name (SAN) attributes in certificate signing requests.

SCEP: Automatic Fetch of One-Time Password and Certificate Thumbprint

Supports retrieving the SCEP one-time password and certificate thumbprint from the OTP server.

Provisioning of Corporate Directory file

Support uploading a local corporate directory file by provisioning. Supports .txt or .cfg format. Users can search and dial contacts from the local directory.

Ability to Disable/Enable Features and Keys on IP Phone

The network administrator can disable access to specific features. The feature is motivated by the requirement on the part of some enterprises to control the setting remotely to comply with company policy.

Supports enabling or disabling the display of DTMF digits on screen during a call

Note: 

  • Microsoft SIP G/W - This version is currently under review by Microsoft for certification with the SIP Gateway environment, intended to replace the existing GA version. AudioCodes has already approved it for use in this environment.
    Until Microsoft completes their approval and updates the version on their servers, OVOC customers can obtain the firmware directly from AudioCodes and begin using it.
  • Zoom – We are finalizing a few additional adjustments for the Zoom environment. An updated version with minor modifications will be released by Zoom, expected within the coming several weeks

 

January 1, 2025
| Version 3.5.0.171
January 15, 2025
| Version 3.4.8.808.21
February 2, 2025
| Version 3.4.8.808.13
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