Global Accelerator (GA) improves stream ingest and playback quality for ApsaraVideo Live by replacing public Internet paths with the Alibaba Cloud GA network. It relies on Alibaba Cloud's high-quality Border Gateway Protocol (BGP) bandwidth and global transmission network to provide nearby access to the global network for live streaming paths. This topic shows you how to enable GA acceleration and configure acceleration channels in the ApsaraVideo Live console.
How it works
Acceleration targets the path between L2 nodes (aggregation nodes) and the live center—the segment most vulnerable to public Internet instability.
Without cross-border acceleration:
L2 nodes transmit live content to the live center over the public Internet. Cross-border and cross-region transmission is especially susceptible to network congestion, packet loss, and latency.
With cross-border acceleration:
GA establishes a direct connection from the L2 node to the live center over the Alibaba Cloud GA network, reducing latency, jitter, and packet loss.
For more information about L2 nodes, see What is Alibaba Cloud CDN?.
Protocol support:
| Protocol | Availability |
|---|---|
| FLV, RTMP, RTS (Real-Time Streaming) | Automatic |
| HLS (HTTP Live Streaming) | Requires a ticket — submit a ticket to have technical support enable it |
Cross-border bandwidth:
For acceleration between the Chinese mainland and regions such as Hong Kong (China), Macao (China), and Taiwan (China), GA uses premium bandwidth by default. For higher network quality, use a leased line instead. See Acceleration configuration options.
Prerequisites
Before you begin, make sure that you have:
An ApsaraVideo Live streaming domain configured in the ApsaraVideo Live console
An Alibaba Cloud enterprise account (required for cross-border acceleration only)
Step 1: Enable the Global Accelerator feature
Enabling GA creates a pay-as-you-go GA instance and automatically configures its acceleration region, listener, and association with the ApsaraVideo Live acceleration path.
Log on to the ApsaraVideo Live console.
In the left-side navigation pane, click Domain Names. The Domain Management page appears.
Find the streaming domain you want to configure and click Domain Settings in the Actions column.
In the left-side navigation pane, choose Streaming Management > Cross-border Acceleration.
Click Activate. The system automatically enables GA for the domain.
In domain name configuration, Acceleration Region uses standard Live CDN acceleration over Internet links. Cross-border Acceleration uses leased lines to reduce packet loss and latency during data transmission across countries and regions.
Step 2: (Optional) Enable cross-border acceleration
To create a cross-border acceleration channel between the Chinese mainland and regions such as Hong Kong (China), Macao (China), and Taiwan (China), your Alibaba Cloud account must meet the following requirements:
Your account must be an enterprise account.
Cross-border data transfer (CDT) must be enabled.
To enable CDT, click Enable CDT for cross-border data transfer in the prompt that appears. After CDT is enabled, you can add cross-border acceleration channels.
The following table shows supported cross-border acceleration scenarios.
| Acceleration type | Live center | Acceleration region |
|---|---|---|
| Stream ingest acceleration, Playback acceleration | Regions in the Chinese mainland | Regions in Hong Kong (China), Macao (China), Taiwan (China), or other countries and regions |
| Stream ingest acceleration, Playback acceleration | Regions in Hong Kong (China), Macao (China), Taiwan (China), or other countries and regions | Regions in the Chinese mainland |
Step 3: Configure an acceleration channel
An acceleration channel maps a specific live stream (identified by AppName and StreamName) to a GA instance. After you complete this step, you get:
A GA instance ID
An acceleration channel with Active status
An accelerated path for stream ingest or playback between the specified regions
To create an acceleration channel:
On the Acceleration Circuits tab, click Create Acceleration Circuit.
In the Create Acceleration Circuit dialog box, configure the following parameters.
Parameter Description AppName The application name in the streaming URL. The channel takes effect only when AppName and StreamName match the values in the streaming URL. Accepts up to 256 characters: digits, uppercase letters, lowercase letters, hyphens (-), and underscores (_). StreamName The stream name in the streaming URL. Accepts the same characters as AppName, plus a wildcard character (*) to accelerate all streams under the specified AppName. Acceleration type Select the direction to accelerate: Streaming Acceleration (playback link from live center to viewers) or Stream Ingest Acceleration (ingest link from streamers to live center). Live center The live center for the current streaming domain. For help selecting a live center, see Live center selection reference. Acceleration channel The acceleration region, selected based on the actual ingest or playback location relative to the live center. For example, if the live center is in Shenzhen and the streamer is in Guangzhou, select Guangzhou as the acceleration region to enable leased-line acceleration between the two cities. If the channel involves cross-border acceleration, complete Step 2 first. Acceleration channel creation Reuse existing: Reuses an existing channel with the same acceleration region. Billing is consolidated under the existing GA instance. New: Creates a new GA instance billed independently. Reused acceleration channel Shown when Acceleration channel creation is set to Reuse existing. Select the channel to reuse. Accelerated bandwidth (Mbit/s) Shown when Acceleration channel creation is set to New. Enter an integer from 10 to 2000. Traffic exceeding 2000 Mbit/s is transmitted over the Internet. Billing note: Pay-as-you-go GA instances incur instance fees and compute unit (CU) fees even when idle. To stop charges, delete the GA instance when you no longer need it (see Step 4). 
Click OK. Channel creation takes 5 to 10 minutes. During this time, Acceleration channel status shows Unavailable. Click Refresh in the upper-right corner to update the status. When creation is complete, the status changes to Active.
To delete an acceleration channel:
Find the channel in the Acceleration Circuits list and click Delete in the Actions column.
Deleting an acceleration channel removes the channel configuration in ApsaraVideo Live but does not delete the underlying GA instance. Idle GA instances continue to incur instance fees and CU fees. To stop all charges, delete the GA instance from the GA console (see Step 4).
Step 4: Manage Global Accelerator instances
On the Acceleration Circuits or GA Instances tab, click an instance ID to open the GA console and view instance details.
| Binding status | Meaning |
|---|---|
| Attached | The GA instance is associated with an active live streaming link. |
| Unattached | The GA instance is idle and not associated with any live stream. This happens after the associated acceleration channel is deleted. |
Do not modify the acceleration region, listener, or other configurations of a GA instance from the GA console after it has been associated with an ApsaraVideo Live acceleration channel. Doing so may cause the acceleration channel to stop working.
To delete an idle instance and stop all charges, find the instance with Binding Status set to Unattached on the GA Instance tab, click the instance ID to go to the GA console, and delete the instance.
Billing
ApsaraVideo Live does not charge separately for cross-border acceleration. After you configure it, the following charges apply:
ApsaraVideo Live: Billed based on traffic usage. See ApsaraVideo Live billing.
Global Accelerator: Billed for the underlying GA instance, including instance fees and CU fees. See Global Accelerator billing.
Pay-as-you-go GA instances incur fees even when idle. Delete instances you no longer need to stop charges.