Wireshark-users: Re: [Wireshark-users] Genband C15 dissectors
From: Jeroen Eeuwes <jeroeneeuwes@xxxxxxxxx>
Date: Fri, 21 Nov 2014 15:46:57 +0100
Hi Bill,

> Note that, since Wireshark is GPL licensed, the vendor is required to
> make available the source of any Wireshark changes they have made.

Only if they distribute the modified version to the public. See here:

https://www.gnu.org/licenses/gpl-faq.html#GPLRequireSourcePostedPublic

Best regards,
Jeroen