What is a Tier 1 Network?
A Tier 1 network is an IP network (typically but not necessarily an Internet Service Provider) which connects to the entire Internet solely via Settlement Free Interconnection, commonly known as peering. Another name for a Tier 1 network is "transit-free", because it does not receive a full transit table from any other network.
Tier 1 networks provide the most direct path between a user and your web site decreasing the time it takes data to travel. This type of network substancially increases load times and download speeds from your web site.