Each NAT gateway specification defines the maximum number of SNAT connections supported by public NAT gateways.
Public NAT Gateway
An SNAT connection is defined by a source IP address (EIP), source port (EIP port), destination IP address, destination port, and a transport layer protocol. An SNAT connection uniquely identifies a session.
The throughput for a NAT gateway is indeed the sum of the bandwidths of all the EIPs configured for all DNAT rules. If a public NAT gateway has two DNAT rules with EIP bandwidths of 10 Mbit/s and 5 Mbit/s, its total throughput will be 15 Mbit/s.
A public NAT gateway supports up to 20 Gbit/s of bandwidth.
The default timeout duration of an SNAT connection over TCP is 900 seconds.
The default timeout duration of an SNAT connection over UDP is 300 seconds.
Select a public NAT gateway specification based on your service requirements. Table 1 lists the public NAT gateway specifications.
Specifications | SNAT Connections | Bandwidth | Packets Per Second (PPS) | Queries Per Second (QPS) |
|---|---|---|---|---|
Small | 10,000 | 20 Gbit/s | 2,000,000 | 10,000 |
Medium | 50,000 | 20 Gbit/s | 2,000,000 | 10,000 |
Large | 200,000 | 20 Gbit/s | 2,000,000 | 10,000 |
Extra-large | 1,000,000 | 20 Gbit/s | 2,000,000 | 10,000 |
- PPS measures the total number of inbound and outbound packets a NAT gateway can handle per second.
- If the number of connections goes beyond the number defined in each public NAT gateway specification, packets will be dropped. To avoid this, create alarm rules on the Cloud Eye console to monitor the number of SNAT connections.
- The number of DNAT rules that can be added for a public NAT gateway is not determined by each specification. Up to 200 DNAT rules can be added to a public NAT gateway. Only the number of DNAT rules that can be added for ultra-large NAT gateway can be increased. You can contact customer service to increase the number.