Interconnect provides direct access to RFC1918 IPs in your VPC with SLA. There are two Cloud interconnect services which are available:

1. Dedicated Interconnect : provides direct physical connection between on premises network and google network. This enables you to transfer large amount of data more efficiently.
A cross connect is established between google network and onpremise network at a common colocation facility.

Dedicated Inteconnect can be configured to provide 99.9% or 99.99% SLA.

2. Partner Interconnect : provides connectivity through a supported service provider. This is useful when the physical datacenter cannot connect with dedicated interconnect.

These supported service provider have existing physical connections to google’s network that they make available for their customers to use. After the connection between the customer on-premise and the service provider is established, one can then request a partner interconnect connection from the service provider.

Cloud Peering

Cloud Peering provides access to google public IP’s only without SLA. There are two Cloud Peering services which are being offered in GCP. These services are useful when access to google and google cloud properties are required.

1. Direct Peering: provides a direct connection between your business network and google network. Direct peering with google is done by exchanging BGP routes between google and the peering entity.

2. Carrier Peering: provides a connection through a supported partner. Once a connection is established you can reach all of google suites and services.

Ideally each of these topics deserves an individual writeup to do proper justice however the intention here is to provide quick short summary providing overall idea about these components. we will plan to cover these individual topics in more detail in another article where deep understanding will be.