Overview

A global connection bandwidth is used by instances to allow communication over the backbone network.

In Cloud Connect, global connection bandwidths are mainly used by central networks.
By default, global connection bandwidths cannot be used by cloud connections. Only some existing users can bind global connection bandwidths to cloud connections.

There are different types of global connection bandwidths that are designed for different application scenarios, including multi-city, geographic-region, and cross-geographic-region bandwidths. Geographic-region and cross-geographic-region bandwidths are often bound to cloud connections for communication on the cloud.

**Table 1** Global connection bandwidth types
Bandwidth Type	Instance Type	Description	Scenario
Multi-city	Global EIPs	Select this type of bandwidth if you need communication between cloud regions in the same region, for example, CN East-Shanghai1 and CN East-Shanghai2 in East China.	A global EIP and its associated resource, such as an ECS or load balancer, have to be in the same region. Multi-city Bandwidth Application Scenario (Global EIP)
Geographic-region	Global EIPs Cloud connection	Select this type of bandwidth if you need communication within a geographic region. Geographic regions include the Chinese mainland, Asia Pacific, and Southern Africa. For example, CN East-Shanghai1 and CN South-Guangzhou are regions in the Chinese mainland. For details about the relationship between geographic regions and Huawei Cloud regions, see Geographic Regions and Huawei Cloud Regions.	A global EIP and its associated resource, such as an ECS or load balancer, have to be in the same geographic region. Geographic-Region Bandwidth Application Scenario (Global EIP) Enterprise routers on a central network are from the same geographic region. Geographic-Region or Cross-Geographic-Region Bandwidth Application Scenario (Central Network)
Cross-geographic-region	Global EIPs Cloud connection	Select this type of bandwidth if you need communication across geographic regions. Geographic regions include the Chinese mainland, Asia Pacific, and Southern Africa. For example, CN East-Shanghai1 and CN-Hong Kong are from different geographic regions. For details about the relationship between geographic regions and Huawei Cloud regions, see Geographic Regions and Huawei Cloud Regions.	A global EIP and its associated resource, such as an ECS or load balancer, are from different geographic regions. Cross-Geographic-Region Bandwidth Application Scenario (Global EIP) Enterprise routers on a central network are from different geographic regions. Geographic-Region or Cross-Geographic-Region Bandwidth Application Scenario (Central Network)

Multi-city Bandwidth Application Scenario (Global EIP)

In this example, a global EIP is bound to an ECS.

The ECS is in the CN East-Shanghai1 region, and the access point of the global EIP is in Hangzhou, a city in East China.

Figure 1 Multi-city bandwidth application scenario (global EIP)

Geographic-Region Bandwidth Application Scenario (Global EIP)

In this example, a global EIP is bound to an ECS.

The ECS is in the CN South-Guangzhou region, and the access point of the global EIP is in Hangzhou. Both Guangzhou and Hangzhou are cities on the Chinese mainland.

Figure 2 Geographic-region bandwidth application scenario (global EIP)

Cross-Geographic-Region Bandwidth Application Scenario (Global EIP)

In this example, a global EIP is bound to an ECS.

The ECS is in the CN-Hong Kong region, and the access point of the global EIP is in Hangzhou. CN-Hong Kong is a cloud region in Asia Pacific, but Hangzhou is a city on the Chinese mainland.

Geographic region 1: Asia Pacific, the geographic region where the ECS is located
Geographic region 2: Chinese mainland, the geographic region where the global EIP is accessed

Ensure that the geographic regions 1 and 2 are configured as above.

Figure 3 Cross-geographic-region bandwidth application scenario (global EIP)

Geographic-Region or Cross-Geographic-Region Bandwidth Application Scenario (Central Network)

In this example, enterprise routers are connected over a cloud connection.

Enterprise router 1 in CN East-Shanghai1 and enterprise router 2 in CN South-Guangzhou are from the same geographic region. A geographic-region bandwidth can be used for communication between the two enterprise routers.
Enterprise router 1 in CN East-Shanghai1 and enterprise router 3 in CN-Hong Kong are in different geographic regions. A cross-geographic-region bandwidth can be used for communication between the two enterprise routers.
- Geographic region 1: Chinese mainland, geographic region where enterprise router 1 is located
- Geographic region 2: Asia Pacific, geographic region where enterprise router 3 is located
Ensure that both the geographic regions of enterprise router 1 and enterprise router 3 have been configured.

Enterprise router 2 in CN South-Guangzhou and enterprise router 3 in CN-Hong Kong are in different geographic regions. A cross-geographic-region bandwidth can be used for communication between the two enterprise routers.
- Geographic region 1: Chinese mainland, geographic region where enterprise router 2 is located
- Geographic region 2: Asia Pacific, geographic region where enterprise router 3 is located

Figure 4 Geographic-region or cross-geographic-region bandwidth application scenario (central network)