Global Accelerator:Add and manage intelligent routing listeners

Add a TCP or UDP listener

1. Configure the listener and protocol.

   1. Log in to the Global Accelerator console.

   2. On the Instances page, find the GA instance that you want to manage and click Configure Listener in the Actions column.

   3. On the Listeners tab, click Add Listener.

      Skip this step if you are adding the first listener or if the Global Accelerator instance has no listeners.

   4. On the Configure Listener & Protocol wizard page, set the following parameters and then click Next.

      Parameter	Description
      Listener Name	Enter a listener name.
      Routing Type	Select a routing type. In this example, select Intelligent Routing. Intelligent Routing: After client requests enter the GA acceleration network, the listener selects a nearby or healthy endpoint group based on factors such as latency and forwards requests to an appropriate endpoint. Custom Routing: Generates a port mapping table based on the listener port range, destination endpoint group port range, and IP addresses of endpoints (vSwitches). Routes traffic deterministically to specific IP addresses and ports on a vSwitch.Add and manage listeners of the Custom routing type. Custom routing listeners are in invitational preview. To use custom routing listeners, submit an application to your account manager. After your application is approved, you can use custom routing listeners.
      Protocol	Select a listener protocol: TCP A connection-oriented transport protocol that requires a connection to be established before data transfer. Provides reliable, ordered byte-stream delivery. UDP A connectionless transport protocol that does not require a connection to be established before data transfer. Does not guarantee datagram delivery or ordering and does not provide retransmission. Warning The maximum transmission unit (MTU) for UDP listeners of GA is 1,452 bytes. When you use a UDP listener, ensure that the MTU of the network interface card (NIC) used for communication between the backend server and GA is greater than 1,452 bytes. Otherwise, packets that exceed this size may be dropped.
      Port	Specify the listener port that is used to receive and forward requests to endpoints. The port number must be in the range of 1 to 65499. You can specify up to 30 ports for each listener. Separate multiple ports with commas (,), for example, 80,90,8080. If you have multiple consecutive ports, you can use a hyphen (-) to specify a port range, for example, 80-85. The ports of TCP, HTTP, and HTTPS listeners cannot be the same. The port of a UDP listener cannot be the same as the port of an HTTPS listener for which HTTP/3 is enabled. Port limits:Intelligent routing listener ports.
      Advanced Settings	Optional. Configure Client Affinity and Idle Connection Timeout Period.
      Client Affinity	Enable or disable client affinity. Source IP: All requests from the same client are routed to the same endpoint. Use for stateful applications. Disable: No client affinity. Requests from the same client may reach different endpoints.
      Idle Connection Timeout Period	Specify the idle timeout period. If no data is transferred over a connection during the timeout period, GA closes the connection. A new connection is established when the next request is received. The value range of this parameter varies based on the listener protocol: TCP listener: 10 to 900 seconds. The default value is 900 seconds. UDP listener: 10 to 20 seconds. The default value is 20 seconds. If your standard GA instance does not support configuring the Idle Connection Timeout Period for an intelligent routing listener, your instance version may not support this feature. To use this feature, contact your business manager to upgrade the instance.

2. Configure endpoints.

   Each listener is associated with an endpoint group. Specify a region for traffic distribution so that GA routes requests to the optimal endpoint in that group.

   On the Configure Endpoint Group wizard page, configure the endpoint group and endpoints as described below, and then click Next.

   For health checks and other settings, see Add a default endpoint group. For an overview, see Endpoint groups and endpoints.

   Parameter	Description
   Endpoint Group Name	Enter a name.
   Region	Select the region of the endpoint group. Select the endpoint group region based on the location of the backend service. If the backend service is in a region that GA does not support, select the supported region closest to the backend service. For example, if users in the United States access servers in the Chinese mainland, select the region where the servers reside or the closest supported region in the Chinese mainland. Acceleration between the Chinese mainland and Hong Kong (China), Macao (China), Taiwan (China), or other countries and regions also requires the corresponding cross-border network configuration. For a subscription instance, purchase and associate a cross-border acceleration bandwidth plan for use with the basic bandwidth plan. For a pay-as-you-go instance, no bandwidth plan is required, but you must select a transmission network type.
   Backend IP Version	Select the IP protocol that the GA instance uses to communicate with the backend service. IPv4: Uses only IPv4 addresses to communicate with the endpoint service. IPv6: Uses only IPv6 addresses to communicate with the endpoint service. IPv4/IPv6 (protocol affinity): The IP protocol that GA uses matches the protocol of the client request. If the client request uses IPv6, GA uses IPv6 to communicate with the endpoint service. If the client request uses IPv4, GA uses IPv4 to communicate with the endpoint service. Note Only standard GA instances that use the pay-as-you-go billing method and have listeners with a smart routing type support the configuration of backend IP protocols. Other types of GA instances do not support this configuration and use IPv4 by default. The backend IP address protocol feature is in invitational preview. To use this feature, contact your business manager. You cannot configure backend IP protocols if the endpoint group region is an Alibaba Cloud point of presence (POP). Call the ListAvailableBusiRegions operation to check whether a region is an Alibaba Cloud POP. You cannot configure OSS as a backend service if the backend IP protocol is set to IPv6 or IPv4/IPv6 (Protocol Affinity).
   Endpoint Configuration	Endpoints process client requests. Configure the following endpoint settings: Backend Service Type: You can select ECS, ALB, NLB, CLB, OSS, ENI, Custom private IP address, Alibaba Cloud Public IP, Custom public IP address, or Custom Domain Name. Note If your standard GA instance does not support backend service types such as ECS, ALB, NLB, CLB (VPC type), ENI, or Custom Private IP Address, the instance version may be outdated. To use these features, contact your business manager to request an instance upgrade. To use GA to accelerate an unsupported Alibaba Cloud backend service type or an on-premises IDC service over a private connection, you can add an endpoint of the Custom Private IP Address type. Custom private IP addresses include, but are not limited to, the following standard private CIDR blocks: 10.0.0.0/8 100.64.0.0/10 172.16.0.0/12 192.168.0.0/16 To ensure high availability, select two or more vSwitches for the Backend Service. If you want to use public IP addresses as private IP addresses, these addresses are treated as private IP addresses when you use the custom private IP feature. If necessary, configure the required routes in the VPC. UDP listeners do not support ALB backend services. To ensure uninterrupted connectivity between the GA instance and backend services, you must configure access policies based on the network connectivity type of the backend service: Public connection: The access policy of the backend service, such as a security group or firewall, must allow traffic from the GA egress public IP address. Private connection: The access policy of the backend service, such as a security group or access control rule, must allow traffic from the vSwitch CIDR block where the backend service resides. You must also ensure that at least eight private IP addresses are available in the vSwitch CIDR block. The egress public IP address of the endpoints for each GA instance is unique and not shared with users of other GA instances. If you select ECS, ALB, NLB, CLB, OSS, ENI, or Custom Private IP Address as the backend service type and a service-linked role does not exist, the system automatically creates one. For more information, see AliyunServiceRoleForGaVpcEndpoint, AliyunServiceRoleForGaAlb, AliyunServiceRoleForGaOss, and AliyunServiceRoleForGaNlb. Backend Service: Enter the IP address, domain name, or instance ID of the backend server. Note TCP listeners of pay-as-you-go standard GA instances support wildcard domains as custom domain name endpoints. For example, you can specify *.example.com to configure acceleration for subdomains. Do not include a protocol prefix (such as https://), a path, or a port number. This feature is being rolled out in phases. To use it, contact your account manager. An endpoint group that contains a wildcard domain supports only one endpoint. You cannot add another wildcard domain, a non-wildcard domain, or an endpoint of another type to the group. The weight of a wildcard domain endpoint is fixed at 255 and cannot be changed. The following instructions for configuring endpoint weights and increasing the number of endpoints do not apply to wildcard domain endpoints. Endpoint groups that use wildcard domains do not support health checks or health-check-based failover between endpoint groups. Client source IP preservation, port mapping, and traffic dialing remain subject to their existing conditions and limits. Monitoring, metering, and billing data is aggregated across the subdomains of a wildcard domain. Monitoring and billing data for individual subdomains is not provided. Weight (Valid values: 0 to 255): Enter an integer from 0 to 255. Global Accelerator routes traffic to endpoints based on their configured weights. Warning If the weight of an endpoint is set to 0, Global Accelerator stops distributing traffic to that endpoint. Proceed with caution. You can click Add Endpoint to add multiple endpoints. You can add up to four endpoints. To add more endpoints, request a quota increase in the Quota Center. For more information, see Manage Global Accelerator quotas. Warning If you select a custom domain name as the backend service type, use a domain name that resolves to the origin server. Do not enter the accelerated CNAME of the current GA instance or a domain name that ultimately resolves to an accelerated IP address of that instance. This prevents traffic sent to the origin from re-entering the current instance and creating a forwarding loop.
   Preserve Client IP	Preserves the client source IP address. When enabled, backend services can retrieve client source IP addresses. For more information, see Preserve client source IPs.
   Port Mapping	If the listener port differs from the endpoint port, you must configure port mapping. Listener Port: The port must be within the port range configured for the current listener. Endpoint Port: The port that the endpoint uses to provide services. Valid values: 1 to 65535. If the listener port is the same as the port that the endpoint uses to provide services, you do not need to configure port mapping. Global Accelerator automatically sends access requests to the endpoint on the listener port. For TCP and UDP listeners, you can click Add Port Mapping to add multiple port mappings. The Listener Port in each port mapping must be unique. You can add up to 30 port mappings. Note If your standard GA instance does not support configuring Port Mapping for TCP or UDP listeners, it may be because the instance version does not support this feature. To use this feature, contact your business manager to apply for an instance upgrade. For TCP listeners: You cannot configure port mapping for virtual endpoint groups. If a virtual endpoint group already exists for the listener, you cannot configure port mapping for the default endpoint group. If port mapping is already configured for the default endpoint group, you cannot add a virtual endpoint group. After you configure port mapping, the following limits apply to subsequent listener changes: Listener protocol: You can switch only between HTTP and HTTPS. Switching between other protocols is not supported. Listener port: The modified listener port range must include all listener ports that have existing port mappings. For example, if the listener port range is 80–82 and is mapped to endpoint ports 100–102, the modified listener port range must include ports 80–82. You can change the range to 80–90, but you cannot narrow it to 80–81. For more information about how to use port mapping, see Use GA port mapping to improve application flexibility and security.
   Traffic Distribution Ratio	Configure the percentage of traffic that is distributed to different endpoint groups. Valid values: 0 to 100. For the subscription billing method, only TCP and UDP listeners support traffic distribution. For the pay-as-you-go billing method, all listener types support traffic distribution. The traffic dial controls traffic allocation to the endpoint group. A value of 0 means that no traffic is forwarded to the endpoint group. Actual traffic distribution also depends on endpoint group scheduling priorities and health check status. A value of 100 does not necessarily mean that the endpoint group receives all traffic to the GA instance. For more information about how to use traffic dialing, see Distribute traffic across endpoint groups in different scenarios.
   Cross-border service configuration	Read the Compliance Commitments Regarding Cross-border Data Transfers and select Agree to the Preceding Compliance Agreement. This step is required only if cross-border acceleration is not enabled for your GA instance and your service configuration involves cross-border acceleration between the Chinese mainland and other regions.

3. Review the configuration.

   On the Configuration Review wizard page, verify the listener and endpoint configurations, and then click Submit.

   To modify configurations, click Edit in the corresponding section to return to the previous page.

   A new listener takes about 3 minutes to become active. Configuration changes take about 1 minute to apply.

Add an HTTP or HTTPS listener

Each client request carries up to 900 request headers. Requests that exceed the limit are dropped. To adjust the limit, contact your account manager.

1. Configure the listener and protocol.

   1. Log in to the Global Accelerator console.

   2. On the Instances page, find the GA instance that you want to manage and click Configure Listener in the Actions column.

   3. On the Listeners tab, click Add Listener.

      Skip this step if you are adding the first listener or if the Global Accelerator instance has no listeners.

   4. On the Configure Listener & Protocol wizard page, set the following parameters and click Next.

      Parameter	Description
      Listener Name	Enter a listener name.
      Routing Type	Select a routing type. In this example, select Intelligent Routing. Intelligent Routing: After client requests enter the GA acceleration network, the listener selects a nearby or healthy endpoint group based on factors such as latency and forwards requests to an appropriate endpoint. Custom Routing: Generates a port mapping table based on the listener port range, destination endpoint group port range, and IP addresses of endpoints (vSwitches). Routes traffic deterministically to specific IP addresses and ports on a vSwitch.Add and manage listeners of the Custom routing type. Custom routing listeners are in invitational preview. To use custom routing listeners, submit an application to your account manager. After your application is approved, you can use custom routing listeners.
      Protocol	Select a listener protocol: HTTPS: Connection-oriented with high reliability. Uses TLS to encrypt data in transit and authenticate the server, protecting data confidentiality and integrity. HTTP: Connection-oriented with high reliability. Transmits data in plaintext.
      Maximum HTTP Version	Select the maximum HTTP version supported by GA. The Maximum HTTP Version is required only when Protocol is set to HTTPS. HTTP/1.1: Based on HTTP/1.0, HTTP/1.1 introduces technologies such as persistent connections and pipelining, but is subject to head-of-line blocking. HTTP/2 (Default): Based on the TCP protocol, HTTP/2 supports multiplexing and header compression to improve the concurrency capability of a single connection. HTTP/3: Uses the QUIC protocol that is based on UDP to resolve the head-of-line blocking issue. HTTP/3 introduces mechanisms such as error recovery, and flow control to improve transmission stability and efficiency. The latest version of the HTTP/3 protocol is h3. This version is supported by Chrome 87 and later. If you use other browsers, make sure that your browser supports HTTP/3. HTTP versions are forward compatible. For example, if you select HTTP/3 as the maximum version but the client does not support HTTP/3, GA also accepts requests over HTTP/2 or HTTP/1.1. Note If your pay-as-you-go GA instance does not support configuring Maximum HTTP Version, it may be because the instance version is not supported. Contact your account manager to upgrade your GA instance. Subscription Global Accelerator instances do not currently support HTTP/3. The TLS Security Policies configuration only applies to non-HTTP/3 connections. HTTP/3 connections use a built-in default security policy.
      Port	Specify the listener port that is used to receive and forward requests to endpoints. The port number must be in the range of 1 to 65499. An HTTP or HTTPS listener supports only one port. The ports of TCP, HTTP, and HTTPS listeners cannot be the same. The port of a UDP listener cannot be the same as the port of an HTTPS listener for which HTTP/3 is enabled.
      Server Certificate	Select an issued, valid server SSL certificate. A server certificate is required only when you set Protocol to HTTPS. Encrypts data transmitted over GA to protect data in transit. For information about purchasing and applying for a certificate, see Purchase a commercial certificate and Submit a certificate application.
      TLS Security Policies	Select the appropriate TLS security policy. This parameter is required only when you set Protocol to HTTPS. System-default and custom policies are available.The TLS Security Policies setting applies only to non-HTTP/3 connections. HTTP/3 connections use a built-in default security policy. A TLS security policy specifies the supported protocol versions and cipher suites. Only standard pay-as-you-go GA instances support custom TLS security policies. You cannot select a custom TLS security policy if you set Maximum HTTP Version for the listener to HTTP/3.
      Advanced Settings	Optional. Configure Client Affinity, Idle Connection Timeout Period, Connection Request Timeout, and Custom HTTP Headers.
      Client Affinity	Enable or disable client affinity: Source IP: All requests from the same client are routed to the same endpoint. Use for stateful applications. Disable: No client affinity. Requests from the same client may reach different endpoints.
      Idle Connection Timeout Period	Specify the idle timeout period. If no access request is received during the timeout period, GA closes the connection. A new connection is established when the next request is received. The value can be from 1 to 60 seconds. The default value is 15 seconds. For pay-as-you-go GA instances, you can request a quota increase in Quota Center. Note If your standard GA instance does not support configuring the Idle Connection Timeout Period for a smart routing listener, your instance version may not support this feature. To use this feature, contact your business manager to upgrade the instance.
      Connection Request Timeout	Specify the request timeout period. If a backend server does not respond within the timeout period, GA stops waiting and returns an HTTP 504 error code to the client. The value can be from 1 to 180 seconds. The default value is 60 seconds. For pay-as-you-go GA instances, you can request a quota increase in Quota Center. Note If your standard GA instance does not support configuring the Connection Request Timeout for a smart routing listener, your instance version may not support this feature. To use this feature, contact your business manager to upgrade the instance.
      Custom HTTP Headers	Select additional HTTP headers. GA-ID: Retrieves the GA instance ID. GA-AP: Retrieves acceleration region information. GA-X-Forwarded-Proto: Retrieves the GA listener protocol. GA-X-Forwarded-Port: Retrieves the GA listener port. X-Real-IP: Retrieves the client's real IP address.

2. Configure endpoints.

   Each listener is associated with an endpoint group. Specify a region for traffic distribution so that GA directs traffic to the optimal endpoint in that group.

   On the Configure Endpoint Group wizard page, set the following parameters and click Next.

   For health checks and other settings, see Add a default endpoint group. For an overview, see Endpoint groups and endpoints.

   Parameter	Description
   Endpoint Group Name	Enter a name.
   Region	Select the region of the endpoint group. Select the endpoint group region based on the location of the backend service. If the backend service is in a region that GA does not support, select the supported region closest to the backend service. For example, if users in the United States access servers in the Chinese mainland, select the region where the servers reside or the closest supported region in the Chinese mainland. Acceleration between the Chinese mainland and Hong Kong (China), Macao (China), Taiwan (China), or other countries and regions also requires the corresponding cross-border network configuration. For a subscription instance, purchase and associate a cross-border acceleration bandwidth plan for use with the basic bandwidth plan. For a pay-as-you-go instance, no bandwidth plan is required, but you must select a transmission network type.
   Backend IP Version	Select the IP protocol that the GA instance uses to communicate with the backend service. IPv4: Uses only IPv4 addresses to communicate with the endpoint service. IPv6: Uses only IPv6 addresses to communicate with the endpoint service. IPv4/IPv6 (protocol affinity): The IP protocol that GA uses matches the protocol of the client request. If the client request uses IPv6, GA uses IPv6 to communicate with the endpoint service. If the client request uses IPv4, GA uses IPv4 to communicate with the endpoint service. Note Only standard GA instances that use the pay-as-you-go billing method and have listeners with a smart routing type support the configuration of backend IP protocols. Other types of GA instances do not support this configuration and use IPv4 by default. The backend IP address protocol feature is in invitational preview. To use this feature, contact your business manager. You cannot configure backend IP protocols if the endpoint group region is an Alibaba Cloud point of presence (POP). Call the ListAvailableBusiRegions operation to check whether a region is an Alibaba Cloud POP. You cannot configure OSS as a backend service if the backend IP protocol is set to IPv6 or IPv4/IPv6 (Protocol Affinity).
   Endpoint Configuration	Endpoints process client requests. Configure the following endpoint settings: Backend Service Type: You can select ECS, ALB, NLB, CLB, OSS, ENI, Custom private IP address, Alibaba Cloud Public IP, Custom public IP address, or Custom Domain Name. Note If your standard GA instance does not support backend service types such as ECS, ALB, NLB, CLB (VPC type), ENI, or Custom Private IP Address, the instance version may be outdated. To use these features, contact your business manager to request an instance upgrade. To use GA to accelerate an unsupported Alibaba Cloud backend service type or an on-premises IDC service over a private connection, you can add an endpoint of the Custom Private IP Address type. Custom private IP addresses include, but are not limited to, the following standard private CIDR blocks: 10.0.0.0/8 100.64.0.0/10 172.16.0.0/12 192.168.0.0/16 To ensure high availability, select two or more vSwitches for the Backend Service. If you want to use public IP addresses as private IP addresses, these addresses are treated as private IP addresses when you use the custom private IP feature. If necessary, configure the required routes in the VPC. To ensure uninterrupted connectivity between the GA instance and backend services, you must configure access policies based on the network connectivity type of the backend service: Public connection: The access policy of the backend service, such as a security group or firewall, must allow traffic from the GA egress public IP address. Private connection: The access policy of the backend service, such as a security group or access control rule, must allow traffic from the vSwitch CIDR block where the backend service resides. You must also ensure that at least eight private IP addresses are available in the vSwitch CIDR block. The egress public IP address of the endpoints for each GA instance is unique and not shared with users of other GA instances. If you select ECS, ALB, NLB, CLB, OSS, ENI, or Custom Private IP Address as the backend service type and a service-linked role does not exist, the system automatically creates one. For more information, see AliyunServiceRoleForGaVpcEndpoint, AliyunServiceRoleForGaAlb, AliyunServiceRoleForGaOss, and AliyunServiceRoleForGaNlb. Backend Service: Enter the IP address, domain name, or instance ID of the backend server. Note TCP listeners of pay-as-you-go standard GA instances support wildcard domains as custom domain name endpoints. For example, you can specify *.example.com to configure acceleration for subdomains. Do not include a protocol prefix (such as https://), a path, or a port number. This feature is being rolled out in phases. To use it, contact your account manager. An endpoint group that contains a wildcard domain supports only one endpoint. You cannot add another wildcard domain, a non-wildcard domain, or an endpoint of another type to the group. The weight of a wildcard domain endpoint is fixed at 255 and cannot be changed. The following instructions for configuring endpoint weights and increasing the number of endpoints do not apply to wildcard domain endpoints. Endpoint groups that use wildcard domains do not support health checks or health-check-based failover between endpoint groups. Client source IP preservation, port mapping, and traffic dialing remain subject to their existing conditions and limits. Monitoring, metering, and billing data is aggregated across the subdomains of a wildcard domain. Monitoring and billing data for individual subdomains is not provided. Weight (Valid values: 0 to 255): Enter an integer from 0 to 255. Global Accelerator routes traffic to endpoints based on their configured weights. Warning If the weight of an endpoint is set to 0, Global Accelerator stops distributing traffic to that endpoint. Proceed with caution. You can click Add Endpoint to add multiple endpoints. You can add up to four endpoints. To add more endpoints, request a quota increase in the Quota Center. For more information, see Manage Global Accelerator quotas. Warning If you select a custom domain name as the backend service type, use a domain name that resolves to the origin server. Do not enter the accelerated CNAME of the current GA instance or a domain name that ultimately resolves to an accelerated IP address of that instance. This prevents traffic sent to the origin from re-entering the current instance and creating a forwarding loop.
   Preserve Client IP	Client IP address preservation is enabled by default for HTTP and HTTPS listeners and cannot be disabled. Backend services can obtain client IP addresses from the X-Forwarded-For HTTP header. For more information, see Preserve client source IP addresses.
   Backend Service Protocol	Select the protocol used by the backend service. Configure this parameter only when you set up an endpoint group for an HTTP or HTTPS listener. HTTP (default) HTTPS Note If the listener protocol is HTTP, the backend service uses HTTP by default and you cannot change the protocol. When the Backend Service Protocol is set to HTTPS, Global Accelerator (GA) supports TLSv1.0, TLSv1.1, TLSv1.2, and TLSv1.3 for connections to backend services, and automatically negotiates an available TLS version with the backend service. If your GA instance does not allow you to select the IP Version for backend service connections, the instance also does not support TLSv1.3 negotiation by default. To use this feature, contact your account manager to request an instance upgrade.
   IP Version	Select the protocol version that Global Accelerator uses to connect to the backend service. This parameter applies only when Backend Service Protocol is set to HTTPS. HTTP/1.1 (default) HTTP/2 HTTP/2 significantly improves performance, reduces latency and network overhead, and enhances the overall access experience for backend HTTPS services. This applies to backend services that already support HTTP/2. If your backend service supports only HTTP/2, you must select HTTP/2. Note If your GA instance does not support selecting the IP Version for a backend service, this may be because the instance version is not supported. To use this feature, please contact your business manager to request an instance upgrade. If you select HTTP/2, the following limits apply: The WebSocket protocol is not supported. The Server Push feature of HTTP/2 is not supported. gRPC requests that are based on HTTP/2 cannot be accelerated.
   Port Mapping	If the listener port differs from the endpoint port, you must configure port mapping. Listener Port: The port must be within the port range configured for the current listener. Endpoint Port: The port that the endpoint uses to provide services. Valid values: 1 to 65535. If the listener port is the same as the port that the endpoint uses to provide services, you do not need to configure port mapping. Global Accelerator automatically sends access requests to the endpoint on the listener port. For HTTP and HTTPS listeners, you can add only one port mapping. Note After you configure port mapping, the following limits apply to subsequent listener changes: Listener protocol: You can switch only between HTTP and HTTPS. Switching between other protocols is not supported. Listener port: The modified listener port range must include all listener ports that have existing port mappings. For example, if the listener port range is 80–82 and is mapped to endpoint ports 100–102, the modified listener port range must include ports 80–82. You can change the range to 80–90, but you cannot narrow it to 80–81. For more information about how to use port mapping, see Use GA port mapping to improve application flexibility and security.
   Traffic Distribution Ratio	Configure the percentage of traffic that is distributed to different endpoint groups. Valid values: 0 to 100. For the subscription billing method, only TCP and UDP listeners support traffic distribution. For the pay-as-you-go billing method, all listener types support traffic distribution. The traffic dial controls traffic allocation to the endpoint group. A value of 0 means that no traffic is forwarded to the endpoint group. Actual traffic distribution also depends on endpoint group scheduling priorities and health check status. A value of 100 does not necessarily mean that the endpoint group receives all traffic to the GA instance. For more information about how to use traffic dialing, see Distribute traffic across endpoint groups in different scenarios.
   Cross-border Service Configuration	Read the Compliance Commitments Regarding Cross-border Data Transfers and select Agree to the Preceding Compliance Agreement. This step is required only if cross-border acceleration is not enabled for your GA instance and your service configuration involves cross-border acceleration between the Chinese mainland and other regions.

3. Review the configuration.

   On the Configuration Review wizard page, verify the listener and endpoint configurations, and then click Submit.

   To modify configurations, click Edit in the corresponding section to return to the previous page.

   A new listener takes about 3 minutes to become active. Configuration changes take about 1 minute to apply.