SwyxPhones need current time to connect to SwyxServer (kb4209)

The information in this article applies to:

  • SwyxWare 2011 RC 1
  • SwyxWare 2011 Beta 2
  • SwyxWare 2011 Beta 1
  • SwyxWare 2011
  • SwyxPhone L615
  • SwyxPhone L680
  • SwyxPhone L660
  • SwyxPhone L640
  • SwyxPhone L620
  • SwyxPhone L540
  • SwyxPhone L520s
  • SwyxPhone L440
  • SwyxPhone L400
  • SwyxPhone L420

[ Summary | Information ]


  • When trying to register with a SwyxPhone at a SwyxServer the following error message is displayed at the phone:
    TLS unavailable: TTT
    Reason for this is an inaccurate time of the SwyxPhone compared to the SwyxServer.
  • When a SwyxPhone tries to establish a call the following error message is displayed on the phone:
    Incompatible security settings
    Reason for this may be an inaccurate time of the SwyxPhone compared to another SwyxPhone or the SwyxServer.


To setup the SwyxPhones properly you have to setup a Time Server in your network to keep all devices at the same time. Alternatively a Windows Domain Controller can act as NTP server. Then the SwyxPhones can successfully register at a SwyxServer.

The configuration of a network time server can be set manually in the web interface of the phone.

But the recommended way is to setup the distribution via DHCP (option 42). After the DHCP parameter configuration the phones need to be restarted.

Note: The NTP server's time is used internally only, not on the SwyxPhone display. The displayed time always depends on the SwyxWare user's location configuration.

With SwyxPhone L6xx it may happen that the error message "Incompatible security settings" is shown at call establishment after you configured NTP. Check with the phone's web interface if system time ("Current UTC Time")  ist correct. A wrong system time may be caused by the quality attribute "Root Dispersion" delivered by the NTP server. SwyxPhones Lxxx ignore all time messages with a "Root Dispersion" greater than 1 second. This is possible if the NTP server has only the local BIOS clock as time source. In that case Windows operating systems are setting  "Root Dispersion" to 10 seconds by default. This value can be retrieved and set with the command line tool "W32TM" on the NTP server. Wherever applicable the NTP server should be synchronized with a reliable primary time source. If that is not possible the local BIOS clock can be regarded as reliable by:

w32tm /config /localclockdispersion:0 /update


There is also the possibility to distribute the related NTP server address via Swyx PhoneManager. Therefore add and configure the following registry key:

  • Type:  REG_SZ (string)
  • Name:  "sntp-addr“
  • Value:  IP-Address


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