| Area | Purpose| Spec and Example | Runtime implementations | Plugin Implementations |
| ------ | ------ | ------ | ------ | ------ | ------ |
-| port mappings | Pass mapping from ports on the host to ports in the container network namespace. | Runtimes should receive the follow plugin config <pre>"runtime_config": {port_mappings": []} </pre> Runtimes should fill in the actual port mappings when the config is passed to plugins e.g. <pre>"runtime_config": {<br /> "port_mappings" : [<br /> { "host_port": 8080, "container_port": 80, "protocol": "tcp" },<br /> { "host_port": 8000, "container_port": 8001, "protocol": "udp" }<br /> ]<br />}</pre> | none | none |
+| port mappings | Pass mapping from ports on the host to ports in the container network namespace. | Operators can ask runtimes to pass port mapping information to plugins, by setting the following in the CNI config <pre>"capabilities": {port_mappings": true} </pre> Runtimes should fill in the actual port mappings when the config is passed to plugins. It should be placed in a new section of the config "runtime_config" e.g. <pre>"runtime_config": {<br /> "port_mappings" : [<br /> { "host_port": 8080, "container_port": 80, "protocol": "tcp" },<br /> { "host_port": 8000, "container_port": 8001, "protocol": "udp" }<br /> ]<br />}</pre> | none | none |
For example, the configuration for a port mapping plugin might look like this to an operator (it should be included as part of a [network configuration list](https://github.com/containernetworking/cni/blob/master/SPEC.md#network-configuration-lists).
```json
{
"name" : "ExamplePlugin",
"type" : "port-mapper",
- "runtime_config": {"port_mappings": []}
+ "capabilities": {"port_mappings": true}
}
```