As well as Source-Talkback with 2Q, and Source-Nexus, Source Elements have released a new version of Source Connect. Source Connect Pro X can handle 5.1 surround so its finally possible to run remote surround mix sessions with picture lock and direct realtime feedback from the remote participants.
Source-Connect Pro X provides all the same features of Source-Connect Pro including Remote Transport Sync but now with 6 channels which can use for 5.1 Surround or 3 pairs of stereo stems. Alternatively you can use the extra channels for multi-channel micing or dedicated timecode with multiple microphone channels for even more flexible remote ADR or review sessions.
Check out Source Connect Pro X and download the free trial version.