Sunday, July 03, 2011

Hangouts Mailbag

Wow, people sure seem to like Hangouts! Following up on a few questions I've been asked in the past week:

Q: "So does this require a certain operating system or version? I would love to conference with a few friends in remote areas with limited computer access."

A: We support all major desktop OSes and browsers (including Mac OS 10.6 "Snow Leopard"). You can see the full list of supported configs here. Other configs may work, but we haven't tested them specifically.

Q: "I was curious about: Latency < 100 ms -> Is this end2end ?"

A: This is the end-to-end transmission latency target.

Q: "Any comment about mobile access?"

A: I'll let our PR answer this: "... we can’t comment on future product plans. However, Google Plus heavily invests in mobile products as we believe you should be able to share and communicate, whether you are on the web, tablet, or phone.”

Q: I love the look of the interface. How much of this design and technology grew out of the Google's Marratech acquisition? 

A: Upon acquisition, the Marratech team was immediately integrated into our group, and they've had a big role in the development of our video technology.

Q: Are you guys planning to open up the tech behind Hangouts? Also, is it based on Muji or was it built from scratch? 

A: Yes, we plan to publish the specifications needed to interoperate with Hangouts. At a high level, it's based on XMPP MUC (XEP-0045) and Jingle (XEP-0166/167), with some other enhancements needed to handle our architecture. We looked at Muji but concluded it wasn't a good fit for our service.

Q: Since Hangout is basically a "meet-me" conference, meaning the participants initiate a session with the conference bridge, why is there a need for ICE and STUN? 

A: ICE is useful for many things besides NAT traversal. We're able to do a bunch of smart things related to mobility, firewall compatibility, and service failover using ICE.