Updated on 2025-07-25 GMT+08:00

Network Load Balancing

Differences Between Application and Network Load Balancing

You can select either application load balancing (HTTP/HTTPS) or network load balancing (TCP/UDP/TLS), or both, for your dedicated load balancers, that best suit your services based on the monitoring metrics, traffic peaks, and regular trends.

  • Application load balancing (HTTP/HTTPS): QPS is a dimension that determines the throughput of an application system. Estimate the QPS that needs to be handled by a load balancer and select the specifications accordingly.
  • Network load balancing (TCP/UDP/TLS): Estimate the maximum concurrent connections that need to be handled by a load balancer and select the specifications accordingly.

Item

Application Load Balancing (HTTP/HTTPS)

Network Load Balancing (TCP/UDP/TLS)

Supported protocols

HTTP, HTTPS, and QUIC

TCP, UDP, and TLS

Capabilities

Handles Layer 7 requests and supports advanced forwarding policies.

Handles Layer 4 requests and does not support advanced forwarding policies.

Application scenarios

Workloads that require high performance at Layer 7, such as real-time audio and video, interactive livestreaming, and game services

Heavy-traffic and high-concurrency workloads at Layer 4, such as file transfer, instant messaging, and online video services

Forwarding capabilities

Routes requests based on HTTP request method, HTTP header, query string, and CIDR block, forwards requests to another URL, and rewrites request URL to forward requests to the specified backend server group.

Listens to requests from all ports in a given port range and routes them to the corresponding ports on the backend servers.

Security control

  • Access control
  • Security groups and network ACLs
  • SSL one-way and mutual authentication
  • Unified certificate management
  • TLS security policies
  • Access control
  • Security groups and network ACLs

Available specifications are displayed on the console and may vary by region.

Network Load Balancing

Table 1 lists the fixed specifications supported by a network load balancer in a single AZ. Select the specification type that best meets your service needs. If the actual service traffic exceeds the maximum performance of each type, new requests will be discarded.

Table 1 Fixed specifications for a network load balancer (TCP/UDP/TLS)

Type

Maximum Concurrent Connections

(TCP/UDP)

Maximum Concurrent Connections

(TLS)

CPS

(TCP/UDP)

CPS

(TLS)

Bandwidth (Mbit/s)

LCUs in an AZ

Small I

500,000

30,000

10,000

500

50

10

Small II

1,000,000

60,000

20,000

1,000

100

20

Medium I

2,000,000

120,000

40,000

2,000

200

40

Medium II

4,000,000

240,000

80,000

4,000

400

80

Large I

10,000,000

600,000

200,000

10,000

1,000

200

Large II

20,000,000

1,200,000

400,000

20,000

2,000

400