Updated on 2022-01-25 GMT+08:00

Product Specifications

The specification refers to the maximum number of SNAT connections supported by a NAT gateway.

An SNAT connection consists of the source IP address, source port, destination IP address, destination port, and transmission-layer protocol. The source IP address and source port are the EIP and port translated by SNAT to access the destination IP address and port of a public network. With these five elements, a connection can be distinguished as a unique session.

The data throughput of a NAT gateway is determined by the sum of EIP bandwidths used by its DNAT rules. For example, a NAT gateway has two DNAT rules. If the bandwidth of the EIP bound to one rule is 10 Mbit/s and that bound to the other is 5 Mbit/s, the throughput of the NAT gateway is 15 Mbit/s.

Each NAT gateway supports up to 10 Gbit/s forwarding bandwidth.

The timeout period of an SNAT connection using TCP is 600 seconds.

The timeout period of an SNAT connection using UDP is 300 seconds.

When creating a NAT gateway, select the proper type based on your service requirements. Table 1 lists the NAT gateway specifications.
Table 1 NAT Gateway type

Type

Maximum Number of SNAT Connections

Small

10,000

Medium

50,000

Large

200,000

Extra-large

1,000,000

  • If the requests exceed the maximum allowed connections of your NAT gateway, your services will be adversely affected. To avoid this situation, you are advised to create alarm rules for the SNAT connection in Cloud Eye.
  • The number of DNAT rules that you can add for a NAT gateway has no relationship with the NAT gateway type. A maximum of 200 DNAT rules can be added for each NAT gateway.