TLS compatibility matrix

[jaimet2]

I am also looking for this information. Here is what I have discovered myself.


I assume that you know how to translate from firmware filenames to version numbers, so that:
firmware filename <modelIdentifier>-<modelCode>.A.0.B.<fileExtension> is version A.B
Example 1: T41S-66.86.0.15.rom is v86.15
Example 2: T20P-9.73.0.50.zip is v73.50


Now back to TLS:

Page 12 of "Yealink SIP IP Phones Release Notes of Version 81" says:
Yealink SIP IP Phones Release Notes of Version x.81.0.70
New Features: Added two new supported TLS versions: TLS 1.1 and TLS 1.2.

Page 10 of "Yealink SIP IP Phones Release Notes of Version 86" says:
Yealink SIP IP Phones Release Notes of Version x.86.0.23
New Features: Supported TLS version 1.3.


So it would seem that:

a) if your phone's latest available firmware version is less than x.81.0.70 then it will only understand TLS v1.0,

b) if your phone's latest available firmware version is greater than or equal to x.81.0.70 but less than x.86.0.23 then it will understand TLS v1.0, v1.1 and v1.2,

c) (and finally!) if your phone's latest available firmware version is greater than or equal to x.86.0.23 then it will understand TLS v1.0, v1.1, v1.2 and v1.3.



To work through 2 examples, I have 2 Yealink phones: a SIP-T19P E2 and a SIP-T20P.

The latest firmware version available for the SIP-T19P E2 is v84.125 (line b above) so its highest TLS version is TLS v1.2.

The latest firmware version available for the SIP-T20P is (only) v73.50 (line a above) so its highest TLS version is (only) TLS v1.0.



I think that the easiest way to find the latest version of firmware available for a particular phone is by using that phone's Support page:

https://support.yealink.com/en/portal/home # for "current" phones
https://support.yealink.com/en/portal/ho...egoryId=44 # for "end-of-life" phones


The way that Yealink have structured their version numbering is "interesting" (that's my polite term). And remember: I am just a customer, just like you, so all of the above could be wrong. Hope this helps. J.