Google Networking Best Practices for Large Deployments - Manual (Page 23)

Network Configuration 23
Traffic Prioritization
You may be able to improve Google Apps performance with traffic prioritization, by giving
Google Apps traffic priority over other network traffic to reduce network latency during
congestion. Traffic prioritization is possible on the data link layer and the network layer; see
the sections below for more information.
You may wish to consider traffic prioritization to reduce potential latency if you have any of the
following environments:
• Hub and spoke network topologies.
• Multiple locations with a single network egress point.
Network Layer (Layer 3) Prioritization
Google Apps uses the same set of IPv4 addresses that other Google products use, including
consumer products like Gmail and Picasa. It is not possible to distinguish traffic to different
products.
If you require network-layer prioritization, we suggest you do one or more of the following:
• Create a proxy PAC file that directs all Google Apps URIs to a proxy that routes only
Google Apps traffic. For more information, see “Proxy PAC file configuration” on page 25.
• Configure your networking equipment to prioritize your proxy network interface.
• Distribute proxies to avoid the creation of a hub and spoke proxy topology.
For information on the Google IPv4 addresses and TCP Port usage, see “Google IPv4
Addresses” on page 19.
Peering
Peering is the direct interconnection of your network to Google's network. This reduces
latency and improves the reliability of the connection between your network and Google.
For most Apps customers, the best way to do this is to choose an ISP or network provider that
already peers with Google. Google peers with many Internet Service Providers in many
locations across the globe. This is the easiest and fastest way to realize the benefits of peering
closely to Google. Contact your ISP to find out if they have peering established with Google.
For larger corporate networks, it may be possible to peer with Google directly. There are a
number of requirements to peer with Google. In general, if you are not peering with other
networks already, then it is more appropriate to let your upstream network provider handle
peering relationships.
For Google's peering requirements, which apply to ISPs, network operators, and corporate
networks, see the Google entry on
PeeringDB . PeeringDB also contains the list of Internet
Exchanges and other locations where Google is capable of peering.
If you or your Internet Service Provider qualifies for peering based on Google's peering
requirements, discuss a peering relationship with your Google Technical Account Manager,
Deployment Team Member, or Google Enterprise Support representative.