Like with several desk phone models (e.g. D717 & D735 w. new LCDs) it is expected that also the PA1+ will have hardware revision in the future. This release candidate here is an initial public available firmware that already is equipped with that forward support of the new hardware revision and all the previous ones. Like with the deskphones, we introduced a compatibility check in the firmware update process. In addition, new settings / setting values are integrated starting with this release here to facilitate identifying the new hardware revision to support e.g. it's handling in provisioning or other related maintenance-, inventory- management tasks.

• a new setting hardware_version 
• the value of hardware_version is shown in WUI System Information /info.htm and PUI System Info screen
• a new "X-snom-" custom HTTP header is added providing the value of setting hardware_version in phone web requests (e.g. provisioning data requests)

In parallel to the introduction of support for L2TP (see below) we made a significant improvement regarding the corresponding configuration tarball URL handling, which can be vital regarding your VoIP endpoint operation continuity:

• SAP-4950: The OpenVPN tarball is now downloaded only if the URL is changed via setting vpn_tarball_url
• SAP-2738: During reprovisioning the 802.1x EAP-TLS WPA configuration .tar file is now only downloaded, if the URL did change #Radius/NPS networks SCPP-8598
• SAP-5285: As a subset of the L2TP feature intro, - the download of the L2TP tarball is only downloaded if the l2tp_tarball_url did change

Conclusion:
Due to the improvement, the device will not just repeatedly download the tar file on every reprovisioning / check-sync as in former FW versions. This change significantly reduces network congestion, the load on the device and mitigates the wear out of the flash storage due to only required re-/write cycles.  But you need to consider that any time you intend to provision the phone with a new configuration via the tar file, you need to change the corresponding tar file URL. Changing just the content of the tar file (e.g. a new 802.1.x EAP-TLS certificate) will not lead the phone to perform the download and processing the new/updated configuration info. One way to ensure continuous reprovisioning changes of content could be the usage of a time-stamp inside the file name and of course updating the tar-file-URL in provisioning XML file accordingly.

These changes are very important to take into consideration and to integrate into your operational workflow, especially when you think about endpoint certificate and updating such frequently due to their period of validity.