Content
- Created by Simon Eckmiller on May 03, 2023 14 minute read
Release Date: 03. Mai 2023
Important Note:
- Please make sure you read ALL of the information below before installing the software on your device.
- Please install and test the software in your environment before mass deployment.
- We encourage you to read and follow our security advisories.
Introduction
The M500 firmware is split into two versions, a specific US version and an European firmware version. This document refers to the European version.
For US, visit DECT M500 Pro-Series Firmware.Â
Changelog
Changes since release version 1.9.x
Audio tunings:
Audio Profile Update M58
The audio profile of the M58 has been adapted to several language specific use cases.
New features:
#MCP-1911, #MCP-2074, #MCP-4709: Password alert message displayed on idle screen of M55/M58
The M55/M58 idle screen will display a password warning message if the Administrator password and/or User password has not been changed from their default values.


Admin password | User password | Password warning message displayed |
---|---|---|
Default value | Default value | Admin PW not set |
Default value | Changed | Admin PW not set |
Changed | Default value | User PW not set |
Changed | Changed | (No message) |
While the password warning message is displayed, the M55’s Call List soft key and M58’s Redial soft key is replaced by the Info soft key.
To temporarily clear the password warning message and restore the Call List / Redial soft key:
- Press Info.
A pop-up message appears. e.g. “For security reason, please edit the admin password.” - On the M55, press
. On the M58, press
.
- Repeat steps 1-2.
The Call List / Redial soft key is now available.
After two minutes, the password warning message reappears and the Call List / Redial soft key is again replaced by the Info soft key. To permanently remove the password warning message, reset the Administrator password and/or User password as necessary.
#MCP-2916: WebUI - Provisioning Page - Reset Remote Base
Added a new section the WebUI Servicing > Provisioning page under Reset Configuration to reset the remote (secondary) base.
This section is shown in the WebUI of the Primary base only. In the WebUI of the Secondary base, the section is hidden.
#MCP-2917: WebUI - Reboot Page - Reboot Remote Base
Added a new section in the WebUI Servicing > Reboot page to reboot remote (secondary) base.
This section is shown in the WebUI of the Primary base only. In the WebUI of the Secondary base, the section is hidden.

#MCP-3488: DectStatistic Page - Support Credential
Created a new support login credential to enable access of the DECT statistics page on the WebUI - http(s)://<host:port>/dect_statistics.kl1.
The username is support.
Added the following new parameter:
Parameter | Description | WUI | PUI | Values | Default |
---|---|---|---|---|---|
profile.support.password | Sets the support password for accessing the DECT Statistics page on the WebUI. This setting is NON-EXPORTABLE. | Servicing → Security → Passwords → Support Password | N/A | text string | support |
#MCP-4378: Add logging support for SIP packets
Added the Servicing > SIP Trace page to the WebUI to display a log of sent and received SIP packets. You can use the SIP Trace page to analyze and troubleshoot SIP issues.

#MCP-4691: Show a WUI reminder for changing default admin/user PW in M500
When the user or admin credential is using default password, a password warning message will be displayed at the top of every WebUI page. This warning message stays until both user and admin passwords are changed.

Improvements and Modifications:
#MCP-1367: WebUI - Status Page - SIP Account
Changed the WebUI Status > System Status page so the Account Status section only displays accounts that are registered.
#MCP-1772: M55/M58 Firmware upgrade - M55/M58 displays countdown warning before upgrade
During a firmware upgrade, while the M55/M58 is receiving the new firmware in the background, a flashing progress icon is displayed on the screen.
When the firmware download is complete, the M55/M58 displays a message with a countdown before installation begins – “New firmware is available. Update is starting in X minutes.”
When the countdown ends, the M55/M58 displays a large hourglass icon on the screen while installing the firmware.
#MCP-3503: Enable DECT Statistic By Default
Changed the default value of the cordless.statistics_enable parameter to 1.
Parameter | Description | WUI | PUI | Values | Default |
---|---|---|---|---|---|
Enable our phone to send DECT statistics to a server via HTTP POST. | N/A | N/A | 0 (disabled) 1 (enabled) | 1 |
As a result, the WebUI Cordless Status page displays the columns Range, Signal, Battery, and In Cradle.
#MCP-3879: Enable RTCP-XR by default
Changed the default value of parameter audio.rtcp_xr.enable to 1 (enabled).
Parameter | Description | WUI | PUI | Values | Default |
---|---|---|---|---|---|
Enables or disables reporting of RTCP XR via SIP to a collector server. RTP Control Protocol Extended Reports (RTCP XR) are used for voice quality assessment and diagnostics. | N/A | N/A | 0 (disabled) 1 (enabled) | 1 |
#MCP-4456: Wideband call is no longer restricted by number of handsets/desksets registered
Removed a restriction that was imposed for wideband call setup in handset. When the number of handsets registered is greater than 5, only narrowband call setup is allowed. The M500, now allows wideband configuration based on the base station localized limit. This will allow every device to setup a wideband call.
#MCP-4624: Air-sync improvement on primary base (dual-cell system)
In a dual cell configuration, set the RPN of secondary base to the preferred RPN list of the primary base when:
- Base is configured as primary base
- One secondary base has joined the multicell system.
When the primary base reboots in the middle of some operations, it will search for secondary base immediately to speed up the air-sync process.
#MCP-4660: SysLog Improvement: Support standard severity levels
On the WebUI System Logs page, changed the values of the Log Level drop-down list to standard severity levels: DEBUG, INFO, NOTICE, WARN, ERROR, CRIT, ALERT, EMERG.
Changed the valid values and default value of parameter log.syslog_level:
Parameter | Description | WUI | PUI | Values | Default |
---|---|---|---|---|---|
Sets the log level. | Configuration → System Logs → Syslog → Log Level | N/A | 7—debug | 4 |
#MCP-4670: WebUI Translations
Updated the language translation for WebUI text strings for German(de), Spanish(es), French(fr), and Italian(it).
#MCP-4846: User needs to be able to easily dial 911/emergency number when in lock screen (M58 Only)
Disabled the keypad lock feature (press # to lock keypad) on the M58 deskset.
Other Improvements and Modifications
Reference | Description |
---|---|
#MCP-3268 | Retain LogSettings after mode switch via webUI |
#MCP-3539 | Add "Base Busy Status" checking before Roaming / Handover |
#MCP-3608 | Improve intersystem communication to ensure proper broadcast to devices |
#MCP-3953 | PUI - Speed up account list access, when Account config is already up-to-date |
#MCP-3954 | PUI - Speed up M55/M58 name list access, when M55/M58 config is already up-to-date |
#MCP-3968 | Upgrade to OBUSPA 6.0.0 |
#MCP-4264 | SysLog Improvement: Added SysLog messages for troubleshooting Site Formation issues. |
#MCP-4265 | Syslog Improvement - Added SysLog messages for troubleshooting Base Firmware Upgrade issues. |
#MCP-4268 | SysLog Improvement: Added SysLog messages for troubleshooting Cordless Upgrade issues. |
#MCP-4288 | SysLog Improvement: Added SysLog messages for troubleshooting Calling (internal/external) issues. |
#MCP-4343 | DECT M55/M58 - Use more precise API to check if connection is active after handover |
#MCP-4440 | M55 low-temp stop Li-ion battery charging |
#MCP-4453 | DECT M55/M58 - Ignore invalid deregistration request |
#MCP-4467 | When M55/M58 is out of range, the signal bar should blink in 1 Hz |
#MCP-4586 | Syslog improvement: Added SysLog messages for troubleshooting DECT Out of Range issues. |
#MCP-4725 | SysLog Improvement: Disable css debug messages |
#MCP-4840 | Update User-Agent for M500 for remote XML sync to mimic config and firmware GET requests |
Corrections:
#MCP-4274: Off hook hard key defect
During transfer/conference (with or without digits entered):
- Pressing the Message/Setting/Intercom hard key would end the call unexpectedly.
- Pressing the Speed Dial List soft key had no function. It should have displayed the speed dial list.
During a ringing incoming call, the Directory/Call History/Redial List/Message soft keys were functioning. They should not be functioning in this state.
#MCP-4301: Bases with IPv6 cannot form site
Corrected an issue where two bases with IPv6 address cannot form site.
Added the following new parameter:
Parameter | Description | WUI | PUI | Values | Default |
---|---|---|---|---|---|
Multicast IPv6 address to be used for site discovery and site synchronization via multicast. Once a site is joined by one or more secondary base(s), multicell.multicast_ipv6_address should not be modified. Configure this setting for a specific base station. This is NOT a site-wide setting. | N/A | N/A | IPv6 address | ff0e:0:0:0:0:0:0:1 |
#MCP-4370: Improved workaround for call drop detection
Improve call state synchronization between M500 and M55 and M58. Call synchronization now utilizes call status broadcast messages.
#MCP-4708: Update TR369 Server URL
Changed the default value of parameter tr369.controller.url to iot.snom.com.
Parameter | Description | WUI | PUI | Values | Default |
---|---|---|---|---|---|
URL of the TR369 controller that our device is connecting to. | Servicing → TR369 → Controller URL | N/A | URI | iot.snom.com |
#MCP-4794: TLS Handshake failure
Device response Handshake Failure when TLS registers to a specific server. Resolved by disabling SIP TLS secure renegotiation via a new parameter.
Added the following new parameter:
Parameter | Description | WUI | PUI | Values | Default |
---|---|---|---|---|---|
Enables or disables SIP TLS secure renegotiation (RFC 5746 compliance). This parameter is only applicable to the TLS connection between the primary base and the server. This parameter is NON-EXPORTABLE. | N/A | N/A | 0 (disabled) 1 (enabled) | 1 |
#MCP-4791: M55/M58 - Auto Reg Success, but keep in Auto Reg screen
When Auto Registration is successful, the M55/M58 remained on the Auto Registration screen, and could not exit to normal Idle screen until timeout and reboot.
Other corrections
Reference | Description |
---|---|
#MCP-1160 | SRTP call does not work for RTP forwarding |
#MCP-2012 | Wrong call state after multiple reject of same call |
#MCP-2068 | WebUI Date Format should not contain YY/MM/DD |
#MCP-2556 | M55/M58 in Secondary Base Click-To-Dial has no audio |
#MCP-2935 | M500 cannot make calls when stun server is set. |
#MCP-2969 | TLS registration failed with Metaswitch server |
#MCP-2972 | M500 - Out of Range Statistic determination - Not localized |
#MCP-3680 | Secondary Base with old RFPI after joined site |
#MCP-3774 | After renaming a Bluetooth device, and then power rebooting the M55/M58, the device name restores to its original name |
#MCP-3146 | M55/M58 outgoing call does not show Restricted Number CID |
#MCP-3183 | Added additional corner case protection for firmware upgrade process |
#MCP-3213 | M500: SIP INFO DTMF method is not recognized on 3CX |
#MCP-3255 | M55/M58 does not indicate out of range, and never comes back in range after base reboot |
#MCP-3646 | Corrected rare case of poor audio on one of the device connected to secondary base |
#MCP-3793 | M500 number of localized handsets is not matching |
#MCP-3795 | M500 installed handset firmware and installed deskset firmware are not matching |
#MCP-3802 | Need to reboot M500 to trigger SUOTA updating shared directory on M55/M58 if importing shared directory file while firmware upgrading is in progress |
#MCP-3810 | 1-way audio between secondary HSs - SRTP Enabled |
#MCP-3838 | M500: HS1 has no TX after local resumed the call - SRTP Enabled |
#MCP-3897 | Syslog error about namespace when performing factory reset |
#MCP-3939 | Localized handsets in Base status webpage is incorrect after deregister M55/M58 via PUI |
#MCP-3959 | M500 LINK LED incorrectly keeps flashing orange after a M55/M58 is registered. If another M55/M58 is registered or the base is rebooted, the LINK LED becomes steady green. |
#MCP-3966 | No disconnect indication when base is down |
#MCP-3980 | Abnormal call status after far end transfer a PARK call |
#MCP-4006 | M500 unresponsive upon making new call when maximum 8 calls has been reached (Happened once) |
#MCP-4020 | Number of connections decrease after handover |
#MCP-4027 | PFK LED stops flashing for held call after roaming to another base |
#MCP-4031 | SuotaManager doesn't stop broadcast while uploading new image to DCX. |
#MCP-4038 | Transfer call will stay on calling screen if the number is unreachable |
#MCP-4091 | Multicell: Blind transfer failure ringback not handled properly |
#MCP-4101 | Page receiver - suppress the disconnect tone when page ends |
#MCP-4133 | Duplicate parameters in a configuration file should be applied in order from top to bottom of the file. The last duplication should be the one that is applied. |
#MCP-4152 | After changing account type from Standard to Key Line Emulation, the M55/M58 cannot make an outgoing call |
#MCP-4207 | M55/M58 does not report SW version after SUOTA Upgrade. |
#MCP-4229 | M500: Cannot disable HTTPS Secure Browsing and port number via WebUI |
#MCP-4231 | Wrong RTP sent during re-invite mechanism |
#MCP-4252 | Improved DECT system broadcast channel |
#MCP-4257 | Some M55/M58 are out of range after base station reboot (Force the M55/M58 lock to the dedicated base station) |
#MCP-4271 | No audio after secondary M55/M58 call resume when connected to OpenSIPS |
#MCP-4273 | M55/M58: On the Directory > LDAP > Search page, the search wildcard * fails to return all the results |
#MCP-4275 | Show M55/M58 local date/time if base does not send/sync date/time to M55/M58 |
#MCP-4276 | M55/M58 does not auto-answer Page ALL |
#MCP-4279 | Far end emits big white noise after handover from Secondary to Primary |
#MCP-4281 | The entire call dropped if the barged-in M55/M58 hangs up |
#MCP-4291 | PFK cannot barge-in to another active call during active call |
#MCP-4296 | Unable to dial out via Speed dial list on transfer/conference dialer |
#MCP-4299 | During conference press "END" softkey cannot end the call |
#MCP-4303 | Incorrect soft key layout in Bluetooth device list |
#MCP-4306 | Keytone enabled during active call. No keytone should be heard during calling. |
#MCP-4307 | Do not show handset’s/deskset's own active call in the call list |
#MCP-4308 | Transfer call list should not show entry with different account |
#MCP-4315 | M55/M58 turn on LCD Backlight and All LED for 5 seconds every time M55/M58 reboots |
#MCP-4317 | No audio after resume the same call twice between bases |
#MCP-4320 | Abnormal PFK status after conferencing with different line |
#MCP-4321 | Incorrect PFK state if there is an incoming call in outgoing calling state |
#MCP-4326 | Primary change WebUI language but Secondary does not take effect |
#MCP-4327 | IPv6: DECT Radio does not turn on Secondary |
#MCP-4329 | BCSP Host API Memory Leak |
#MCP-4335 | No softkey on inbound call screen after Transfer |
#MCP-4339 | Abnormal call screen when blind transfer a hold call |
#MCP-4342 | Fail to establish call for particular M55/M58 |
#MCP-4346 | Invalid transfer action after answering incoming call during transfer |
#MCP-4347 | M55/M58 release call if inbound and outbound call at the same time (call collision) |
#MCP-4351 | IPv6 air sync fail. In the base status webpage, the air sync status is showing as unsync when the base is configured in IPv6. |
#MCP-4354 | Speed dial list cannot scroll down to the last item |
#MCP-4355 | Outbound call fails with RingCentrail when TLS is enabled |
#MCP-4356 | WebUI locked up if power down M55, then keep refreshing cordless status webpage |
#MCP-4358 | Correct an erroneous tone that may get generated on the device when ring volume is turned off during an incoming call |
#MCP-4365 | Fail to deliver updated call status to M55/M58 if more than 4 incoming calls arrive at the same time. |
#MCP-4366 | Call ID does not change after transfer |
#MCP-4395 | Duplicate tags in XML config causes phone to crash |
#MCP-4396 | M500 (Realtek RTL8363NB) : PC port VLAN tagging not working on bootup |
#MCP-4399 | Fail to Replicate Record Created by Manual Registration |
#MCP-4402 | Voicemail hardkey does not dial out on account 9 and up |
#MCP-4404 | Pressing hash key will trigger manual registration on "register via" menu |
#MCP-4406 | Local directory contact and speed dial should have 16 dial line |
#MCP-4411 | Registering screen pop up for a second after canceling manual registration |
#MCP-4412 | M55 cannot completely go back to Idle and end call, when put on cradle |
#MCP-4427 | Incorrect screen displayed when inbound call right after register |
#MCP-4436 | Cannot show M55/M58 name, if registered M55/M58 + Group > 48 |
#MCP-4437 | LCD Backlight cannot turn off, after timeout from Manual Registration |
#MCP-4438 | No function on call history "Save" softkey |
#MCP-4439 | Intercom hard key should be disabled during intercom or paging call |
#MCP-4441 | Unexpected center key action on manual registration message |
#MCP-4444 | Bluetooth pairing screen should not be able to dismiss by center key |
#MCP-4459 | "Call Forward No Answer" PFK label is clipped |
#MCP-4469 | Improve robustness of Wideband handover |
#MCP-4475 | M500 : LLDP-MED policy change cannot apply without unplug/replug |
#MCP-4477 | trigger provisioning on secondary when primary receives a check-sync NOTIFY |
#MCP-4485 | Using Wrong Codec |
#MCP-4486 | One M55/M58 Failed to update firmware version to Base |
#MCP-4547 | During paging call, M55/M58 answers the call waiting call, M55/M58 doesn't drop the paging call |
#MCP-4553 | M55/M58 cannot be paged when it is on Paging menu |
#MCP-4562 | M55 Miss call option page empty |
#MCP-4566 | During Call transfer, M55/M58 active call screen frozen, until call release |
#MCP-4567 | M55/M58 On Secondary fail to update shared directory |
#MCP-4573 | Sometimes calls would be dropped after handover |
#MCP-4578 | CallSlotModel - Attended transfer fail at secondary base |
#MCP-4583 | Missing device MAC address info on the syslog message |
#MCP-4584 | Early attended transfer failure not handled properly |
#MCP-4588 | Improve call release message handling |
#MCP-4601 | Caller name duplicated from caller number |
#MCP-4603 | Predial Fail to dial, Post-dial normal |
#MCP-4607 | After import config, WebUI was blank |
#MCP-4612 | 2-way audio turns bad after a min when the Secondary M55/M58 is on the call, resume after another 1 min. |
#MCP-4622 | After attended transfer fail, no transfer failed splash screen |
#MCP-4634 | LCD backlight turn off during Hold Call state |
#MCP-4640 | Removed Network Conference configuration from WebUI |
#MCP-4648 | M55/M58 cannot receive incoming ring before making outbound call |
#MCP-4655 | Correct manual account type changes not getting applied properly |
#MCP-4661 | Correct error handling when DECT location registration is unsuccessful |
#MCP-4673 | Correct logging message when paging occurs |
#MCP-4684 | DECT M55/M58 - Forever Search for Base |
#MCP-4688 | M55/M58 cannot send Firmware version, if call started |
#MCP-4694 | Does not use PAI/RPID for inbound call |
#MCP-4710 | Incorrect Reboot Counter |
#MCP-4712 | Correct race condition that may cause incorrect device configuration when devices are powered up |
#MCP-4714 | M500: cannot open the wireshark data from webUI system log pcap |
#MCP-4719 | M55/M58 memory leak found when access call list during active call |
#MCP-4736 | Correct out of range status from not being reported correctly in some circumstances |
#MCP-4767 | Dect Statistic failed to pull on some handsets/desksets |
#MCP-4768 | Correct localization information when performing several handover in succession |
#MCP-4781 | M55/M58 - Align Active Call Top Row Icons with Idle screen |
#MCP-4787 | Answering call at primary when it has already been answered at secondary |
#MCP-4799 | Call waiting call was disappear - Concurrent ringing (INT) |
#MCP-4800 | M500 call failure with opus/ilbc codecs |
#MCP-4801 | Correct simultaneous off-hook with multiple devices from being reported correctly |
#MCP-4804 | Fail To Answer Call Concurrently - M55/M58 frozen in "Incoming Call" |
#MCP-4845 | M500 Dual base Localized list corruption as a result of M55/M58 reboot |
#MCP-4849 | Can't perform feature access code when the code include "#" in multicell |
M500 base station
File Name | File size | SHA 256 Checksum | File name |
---|---|---|---|
1.11.1 | 55.7 MB | be6b214bff06502cd3eebd180889bf48a221b60e707e45dc618ce583c4851adf | https://downloads.snom.com/M500/M500-1.11.1.img |
M55 handset
File Name | File size | SHA 256 Checksum | Supported language | File name |
---|---|---|---|---|
1.11.1 | 1.5 MB | e8ac46be37e45b205ea579b989b131640b0df1be1a7008f2611073c97231ce6f | English, French, Spanish, German, Italian, Dutch, Greek, Polish | https://downloads.snom.com/M500/M55-1.11.1.img |
M58 deskset
File Name | File size | SHA 256 Checksum | Supported language | File name |
---|---|---|---|---|
1.11.1 | 1.5 MB | a924c529f3d48d15daa28de044ac8f7bca861e55ce36f6ec64705c6e12d95ea3 | English, French, Spanish, German, Italian, Dutch, Greek, Polish | https://downloads.snom.com/M500/M58-1.11.1.img |