First Published: May 7, 2026

Cisco IP DECT 6800 Series Release Notes for Firmware Release 5.1(3)SR1

These release notes support the Cisco IP DECT 6800 Series running Firmware Release 5.1(3)SR1.

This release supports the following devices:

  • Cisco IP DECT 110 Single-Cell Base Station

  • Cisco IP DECT 210 Multi-Cell Base Station

  • Cisco IP DECT 110 Repeater

  • Cisco IP DECT Phone 6823 Handset

  • Cisco IP DECT Phone 6825 Handset

  • Cisco IP DECT Phone 6825 Ruggedized Handset

The Cisco IP DECT 6800 Series is compatible with the following systems:

  • BroadSoft BroadWorks 22.0 and later

  • Asterisk 13.1 and later

The firmware release versions are:

  • Base station version 5.1(3)SR1: Displayed on the device as firmware version:

    • DBS-110: IPDect-DBS110-5-1-3MPP0101-9_REL.zip

    • DBS-210: IPDect-DBS210_5-1-3MPP0101-9_REL.zip

  • Handset version 5.1(3)SR1: Displayed on the device as firmware version:

    • 6823: IPDect-PH6823_5-1-3MPP0101-9_REL.zip

    • 6825: IPDect-PH6825_5-1-3MPP0101-9_REL.zip

    • 6825-RGD: IPDect-PH6825RGD_5-1-3MPP0101-9_REL.zip

New and Changed Features

New Features

Select audio tuning by specific operation

Feature Highlights

Admins and users can now select audio tuning options directly from the handset's main menu. Each audio tuning can be activated using a dedicated key combination:

Avoid merging the two calls when attempting to transfer

Feature Highlights

Choose between a merge and a transfer of a call.

When the Transfer button is pressed, a menu should appear allowing the user to choose between merging calls or performing a transfer.

Support consult transfer on the second line of handset

Feature Highlight

Ease of consult transfer on the second line of the handset. When attempting to consult a transfer from a second line, there's no need to select the line to complete the transfer.

Upgrade the Firmware

You can upgrade the base station and handset firmware with TFTP, HTTP, or HTTPS. You upgrade the base station first and then upgrade the handsets after the base station upgrade completes. The base station upgrade may take about 30 minutes to 1 hour to complete and reboot. The handset upgrade may take 20-30 minutes to download and verify, and an extra few minutes to load the new firmware file. The handset must be placed in the charger and not removed until the handset loads the firmware file and reboots.

You can upgrade Cisco IP DECT 210 Multi-Cell Base Station to Firmware Release 5.1(2) only if the base station is currently running release 5.0(1) or 4.8(1)SR1. If the base station is currently running release 4.7 or 4.8, you must upgrade the base station to release 5.0(1) or 4.8(1)SR1 before upgrading to release 5.1(3)SR1. If the base station is currently running release 4.5, you must upgrade the base station to release 4.6 in factory reset mode before upgrading to release 4.8(1) SR1.

You can upgrade Cisco IP DECT 110 Single-Cell Base Station to Firmware Release 5.1(3) if the base station is currently running release 5.0(1) or 4.8(1) SR1. If the base station is currently running release 4.8, you must upgrade the base station to release 5.0(1) or 4.8(1) SR1 before upgrading to release 5.1(3)SR1.

You access the Cisco Software Download page to get the firmware in zip files. The zip files contain these firmware files:

  • For the base station, the zip filename starts with:

    • IPDect-DBS110 for Cisco IP DECT 110 Single-Cell Base Station.

    • IPDect-DBS210 for Cisco IP DECT 210 Multi-Cell Base Station.

  • For the handset, the zip filename starts with:

    • IPDect-PH6823 for Cisco IP DECT Phone 6823 Handset.

    • IPDect-PH6825 for Cisco IP DECT Phone 6825 Handset.

    • IPDect-PH6825RGD for Cisco IP DECT Phone 6825 Ruggedized Handset.

The Firmware Release 5.1(3)SR1 zip files contain these files:

  • Base station:

    • Cisco IP DECT 110 Single-Cell Base Station: IPDect-DBS110_5-1-3-MPP0101-9_REL.zip

    • Cisco IP DECT 210 Multi-Cell Base Station: IPDect-DBS210_5-1-3-MPP0101-9_REL.zip

  • Handsets:

    • Cisco IP DECT Phone 6823 Handset: IPDect-PH6823_5-1-3-MPP0101-9_REL.zip

    • Cisco IP DECT Phone 6825 Handset: IPDect-PH6825_5-1-3-MPP0101-9_REL.zip

    • Cisco IP DECT Phone 6825 Ruggedized Handset: IPDect-PH6825RGD_5-1-3-MPP0101-9_REL.zip


Note

  • If you haven't modified the password in the base station running Firmware version 4.8 or 4.8(1)SR1 and you upgrade the base station, the administration user ID and password change request displays when you login to the base station.

  • From Firmware Release 5.1(3)SR1, if you need to downgrade to an earlier release, you can downgrade to the latest branch of the Firmware Release 5.0(1) or 4.8(1)SR1. You must perform a factory reset on the base station to downgrade. This reset will set the administration user ID and password to the default values.

For detailed information about the upgrade or downgrade procedure, refer to the "Maintenance" chapter in the Cisco IP DECT 6800 Series Administration Guide.

Before you begin

You need the TFTP, HTTP, or HTTPS server information.

Procedure

Step 1

From your browser, go to https://software.cisco.com/download/home/286323307.

Step 2

If required, sign in with your user ID and password.

Step 3

Click IP DECT 110 Repeater with Multiplatform Firmware.

  1. Select All Release > MPP DECT v5 > 5.1(3)SR1.

  2. Download the zip file for the required version.

  3. Return to https://software.cisco.com/download/home/286323307.

Step 4

Click IP DECT 110 Single-Cell Base Station with Multiplatform Firmware.

  1. Select All Release > MPP DECT v5 > 5.1(3)SR1.

  2. Download the zip file for the required version.

  3. Return to https://software.cisco.com/download/home/286323307.

Step 5

Click IP DECT 210 Multi-Cell Base Station with Multiplatform Firmware.

  1. Select All Release > MPP DECT v5 > 5.1(3)SR1.

  2. Download the zip file for the required version.

  3. Return to https://software.cisco.com/download/home/286323307.

Step 6

Click IP DECT 6823 with Multiplatform Firmware.

  1. Select All Release > MPP DECT v5 > 5.1(3)SR1.

  2. Download the zip file for the required version.

  3. Return to https://software.cisco.com/download/home/286323307.

Step 7

Click IP DECT 6825 with Multiplatform Firmware.

  1. Select All Release > MPP DECT v5 > 5.1(3)SR1.

  2. Download the zip file for the required version.

    You can download both IP DECT 6825 with Multiplatform Firmware and IP DECT 6825 Ruggedized with Multiplatform Firmware from this page.

  3. Return to https://software.cisco.com/download/home/286323307.

Step 8

Unzip the downloaded files to your computer.

Step 9

Access the TFTP server file system.

Step 10

If not available, create a Cisco directory.

Step 11

Open the Cisco directory.

Step 12

Copy the new base station firmware file to the Cisco folder.

Step 13

Copy the new handset firmware file to the Cisco folder.

Step 14

Complete the upgrade as described in the Cisco IP DECT 6800 Series Administration Guide.

Limitations and Restrictions

System Behavior During Times of Network Congestion

Anything that degrades network performance can affect phone system voice quality, and in some cases, can cause a call to drop. Sources of network degradation can include, but are not limited to, the following activities:

  • Administrative tasks, such as an internal port scan or security scan

  • Attacks that occur on your network, such as a Denial of Service attack

Caller Identification and Other Phone Functions

Caller identification or other phone functions have not been verified with third-party applications for the visually or hearing impaired.

Base Station Firmware Downgrade Limitation

After the upgrade for V460 B4, a downgrade of the base to a firmware version earlier than V460 B2 requires you to factory reset the base. This factory reset will reset the login credentials to the defaults. If you don't perform the factory reset, you can't log into the administration web pages.

After the upgrade to Firmware version 5.0(1), you can downgrade the base station only to the latest branch of the Firmware version 4.8(1) SR1. This downgrade requires you to factory reset the base station. The factory reset will reset the login credentials to the defaults. If you don't perform the factory reset, you can't log into the administration web pages.

Base Station Alert Due to a Clock Synchronization Error

The base station self-check process fails if there’s a clock synchronization error. When this error occurs, the LED on the base station flashes red, amber, and green. In this case, we recommend the standard RMA process.

Open Caveats

The following caveats are open at the time of the release.

  • CSCwt67703 - No audio is heard when the G729 codec is negotiated on the MultiCell network.

Resolved Caveats

The following caveats were resolved for the release:

  • CSCwq97768 'Loud ringer' has low audio volume

  • CSCwq84887 Subscribe Line-Seize Failed

  • CSCwr50363 DECT bases upgraded to 5.1.3 reinitialise eth rx every ~1 minute

  • CSCwr50359 FKS does not work when trying to disable CFU from server side

  • CSCwq13431 IPDECT base stations reboot post upgrade to 5.1.3

  • CSCwq11215 DECT SCA handset does not respond NOTIFY for Line Seize

  • CSCwr50350 LCG-Local Call Group transfer does not work

  • CSCwo48207 6823 phones reboot each time the user searches for a contact in the directory ALL

  • CSCwq97518 Media stats are not sent by DBS110 when the Call Statistics in SIP is enabled after the base is idle for approximately 6 hours

  • CSCwr81414 The second call DN will be truncated on the 6823 handset

  • CSCwr82844 missing line identifier once call is active

  • CSCwt25853 Cisco DECT BS-210 - unexpected reboot due to RSE_HEAP_TAIL_OVERWRITE