12. externalinternal SIP Proxy a w

13. externalinternal STUN/ TURN Server SIP Proxy a w b e c d x y

14. Public Providers Reverse proxy External Edge server Federated Network External Users Perimeter network Internal UC end points EE pool IP-PSTN gateway PBX Mediation Server (optional) PSTN Front-end Back-end ICE endpoints Clients and server Terminates media Audio Video Desktop/Application Sharing 1:1 File Transfer (Not: PowerPoint sharing) Edge Server Provides STUN and TURN Does not terminate any media Is not an ICE endpoint SBA/SBS Exchange UM

16. EndpointAV Edge SIP Register 200 OK ms-user-logon-data: RemoteUser sip:Mras.contoso.com SIP Service internet 200 OK edge.contoso.com 3478 443 77qq8yXccBc2lwOmFy Wnujl0eo00YkV/5dg= 480 Service 200 OK MRAS Access Edge Front End Server

17. EndpointAV Edge SIP Invite 200 OK 94.245.124.238 3478 443 77qq8yXccBc2lwOF Wnujl0eo00YkV/5g= 480 Service 200 OK Access Edge Front End Server MRAS

19. allocate UDP allocate TCP a b d c e a e d c b local remote default candidates c MRAS NIC 1

20. allocate TCP a b c a c b local remote default candidates c MRAS NIC 1

21. a b d c e a e d c b local remote default candidates f c MRAS NIC 1 NIC 2 f

22. a a e d c b local remote default candidates c NIC AV Edge c e a e d c b remote local default candidates c NIC b d wv z x y v z y x w y v z y x w y SIP INVITE c :: a, b, c, d, e 183 Session progress y :: v, w, x, y, z 200 OK y :: v, w, x, y, z AV Edge SIP

27. Home 1 Lync Home 2 Lync Work 1 Lync AV MCU Exchange UM Mediation Server Work 2 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443

28. Work 1 Lync AV MCU Exchange UM Mediation Server Work 2 w1 w2 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443 w1 w2 w1

29. Home 1 Lync Work 1 Lync AV MCU Exchange UM Mediation Server h1 w1 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443 w1 h1

30. AV Edge Home 1 Lync h1 h2 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443 h1 Home 2 Lync h2

31. w2 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443 w2 Home 1 Lync Work 2 Lync AV MCU w2 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443 w1 Work 1 Lync AV MCU

32. w2 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443 w2 Home 1 Lync Work 2 Lync AV MCU w2 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443 w1 Work 1 Lync AV MCU

33. w2 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443 w2 Home 1 Lync Work 2 Lync AV MCU w2 UDP/TCP 50,000. UDP/TCP 59,999 UDP 3478 TCP 443 w1 Work 1 Lync AV MCU

34. Source PortDestination Port TCP 50,000-59,999TCP 443 UDP 3478 AnyTCP 443 AnyUDP 3478 Source IPDestination IP A/V Edge service interfaceAny A/V Edge service interfaceAny A/V Edge service interface AnyA/V Edge service interface

37. EndpointAV Edge SIP Register SIP Service Service MRAS Access Edge Front End Server AV Edge MRAS allocate UDP allocate TCP

43. Edge is awesome!