Known STUN clients:
- xten softphones: X-Lite, X-PRO, eyeBeam
- Linux client on http://sourceforge.net/projects/stun/
- SNOM Phones
- Cisco Ata v 3.0 firmware
- pbxnsip PBX for trunks
- Grandstream Budgetone and Handytone
- Hotsip Active Client
- Sipura All SPA Products
- Leadtek Research BVA8051, BVA8052, BVA8053, BVA8055
- SIPPhone Call-In-One
- GnomeMeeting H.323 and SIP Open Source softphone GnomeMeeting Project
- PJSUA Open Source Console-based SIP User Agent
- Doubango – open source, cross-platform 3GPP NGN/IMS Framework
- IMSDroid open source SIP/IMS Client for Android
You can find a list of public STUN test servers on the main STUN page.