When making a 3-way call involving an external number, there is an issue with one of the parties losing audio when the external number answers. This only happens when the 3-way call is established before the external number answers. To clarify: A+B are internal C is external 1. A calls B 2. B answers 3. A puts B on hold and dials C 4. C is ringing 5. A establishes the 3-way call while C is ringing 6. A+B hear the ringing and each other 7. C answers. 8. B can no longer hear A+C, and they cant hear B but can hear each other 9. B holds and unholds the call 10. A+B+C can now hear each other Please see attached logs. The handsets involved are a Cisco SPA504G and Linksys SPA941, and the same has been replicated using Snom M3.