Google Networking Best Practices for Large Deployments - Manual (Page 22)

22 Networking Best Practices for Large Deployments
Google+ Hangouts
Google+ Hangouts attempts to establish a connection between a participant and a Google
server using a method similar to that of Google Talk Voice and Video. For details, see the
Administrator Help Center .
Firewall Configurations
To provide users with the full capabilities (voice, video, and text) of Google Talk Voice and
Video and Google+ Hangouts, allow UDP out from clients on your network. See the Help
Center article “
Optimize your Network for Hangouts ” for more detail.
If you don’t want to allow UDP out from clients on your network, at a minimum, permit TCP out
from clients on your network to Google on ports 80 and 443. (See the Help Center article
“
Optimize your Network for Hangouts ” for more detail.) Remember, though, that forcing a
TCP connection for services such as voice and video may create a poor experience for your
users; therefore, we recommend allowing the use of UDP out from your network.
Google Talk negotiates and establishes voice and video calls using the open source
libjingle
library. For more information, see the libjingle Google Code Project Page . A
diagram of network behavior for the libjingle library is available in the Libjingle Network
Diagram .
Network Routing
When routing to Google Apps, the simplest network routing generally provides the best
performance. Reduce complexity and unnecessary network routing from users’ locations to
Google data centers. A goal for your network design should be to reduce the total round trip
time from your network to Google. If you see performance issues, address any latency
problems before you increase bandwidth.
To achieve the best performance with connections to Google Apps:
• Route network traffic to the Internet as close to the end user as possible, in terms of
geography and network topology.
• Focus on addressing latency issues over bandwidth requirements. Above a minimum
bandwidth level, bandwidth considerations are generally less significant for Google Apps.
• Open your firewalls to the ports that Google Apps services use.
• Consider traffic prioritization if you are using a hub-and-spoke network topology or if your
network has multiple locations with a single network egress point.
WAN Optimization
When planning your network cloud strategy, try to reduce latency and round-trip time. Users in
remote offices will experience reduced performance if WAN traffic must traverse large
geographical areas to reach the Internet. Implement network egress points as geographically
close as possible to the user, since traffic across your WAN causes more congestion on some
of your more bit-expensive links. Parts of this optimization can be accomplished through DNS
resolution changes. For more information, see “DNS Resolution” on page 29.