Add network metrics to process semantic conventions

CHANGELOG.md

@@ -25,6 +25,8 @@ release.
 
 - Add `net.app.protocol.*` attributes
   ([#2602](https://github.com/open-telemetry/opentelemetry-specification/pull/2602)).
+- Add network metrics to process semantic conventions
+  ([#2556](https://github.com/open-telemetry/opentelemetry-specification/pull/2556))
 - Adopt attribute requirement levels in semantic conventions
   ([#2594](https://github.com/open-telemetry/opentelemetry-specification/pull/2594))
 - Add semantic conventions for GraphQL

specification/metrics/semantic_conventions/process-metrics.md

@@ -38,6 +38,7 @@ Below is a table of Process metric instruments.
 | `process.memory.usage`    | UpDownCounter                                     | By    | The amount of physical memory in use.                                                                                               |                                                                                                                                                                                                 |
 | `process.memory.virtual`  | UpDownCounter                                     | By    | The amount of committed virtual memory.                                                                                             |                                                                                                                                                                                                 |
 | `process.disk.io`         | Counter                                           | By    | Disk bytes transferred.                                                                                                             | `direction` SHOULD be one of: `read`, `write`                                                                                                                                                   |
+| `process.network.io`      | Counter                                           | By    | Network bytes transferred.                                                                                                          | `direction` SHOULD be one of: `receive`, `transmit`                                                                                                                                           |
 
 ## Attributes