license of PJSIP

[canbobo]

Does any body concern about the legality risk of PJSIP usage of Yealink phones?
I found it is listed in the link of Yealink official web https://www.yealink.com/onepage_83.html
It is licensed under GPLv2.
PJSIP is a library as described in it official web
https://www.pjsip.org/
Does this mean Yealink does not buy commercial license and they should publish all their linked source code which I cannot find on their official web.

BR

[canbobo]

Still no official answer from any one?

[canbobo]

My personal feeling is that if Yealink does not buy commercial license of PJSIP, they will face source code contamination issue, and all products using PJSIP is impacted.

[canbobo]

I raised this question one month ago, still no any answer or comment.
I began to wonder if there was a legality issue when I bought Yealink.