This topic describes the scenarios of Express Connect. If you want your on-premises data center to communicate with an Alibaba Cloud VPC through a private network, you can establish a physical connection by using a physical connection interface of Alibaba Cloud or using a pre-deployed leased line from a partner of Alibaba Cloud. Through physical connections, you can implement high-quality, highly reliable, and highly secure internal communication between your on-premises data center and the VPC.

Connect an on-premises data center to a VPC

If your on-premises data center needs to communicate with an Alibaba Cloud VPC through a private network, you can apply for a physical connection interface from Alibaba Cloud to establish a physical connection between the on-premises data center and the VPC. Through physical connections, you can implement high-quality, highly reliable, and highly secure internal communication between your on-premises data center and the VPC.

Scenario 1: Implement disaster recovery for large and medium-sized enterprises

For key services that requires high availability, we recommend that you establish multiple physical connections at multiple access points. This topology guarantees the disaster recovery capability of your services in the case of connection failures caused by optical fiber disconnections, device faults, and access point failures. This topology applies whether you use a physical connection interface of Alibaba Cloud or use a shared pre-deployed leased line of a partner of Alibaba Cloud.

Scenario 2: Build high-elasticity and high-availability architecture for large enterprises

Assume that your company needs to increase its business operations because of increased sales. However, the current resources of your on-premises data center can no longer accommodate sufficient servers. You can use physical connections to connect the on-premises data center to Alibaba Cloud and use equal-cost multi-path routing (ECMP) to increase the bandwidth of leased lines. By doing so, you can handle T-level traffic in an elastic and easy way, and meet service needs. To use ECMP, open a ticket.

This topology allows services to be recovered from device faults, leased line connection faults, and access point failures. This topology applies only when you use physical connection interfaces of Alibaba Cloud to establish physical connections.

Scenario 3: Establish a simple network architecture for non-critical services

For non-critical services that do not require high elasticity and availability, for example, the development and test environment, we recommend that you establish at least two physical connections at one access point and connect the two leased lines to different devices. This topology supports failovers in the case of failures of a single device, but does not support failovers in the case of access point failures. This topology applies only when you use a shared pre-deployed leased line of a partner.