Port, address clarifications

CHANGELOG.md

@@ -61,6 +61,8 @@ release.
   ([#276](https://github.com/open-telemetry/semantic-conventions/pull/276))
 - Add host cpu resource attributes.
   ([#209](https://github.com/open-telemetry/semantic-conventions/pull/209))
+- Encourage setting `network.transport` when reporting port numbers
+  ([#289](https://github.com/open-telemetry/semantic-conventions/pull/289))
 
 ## v1.21.0 (2023-07-13)
 

docs/database/database-spans.md

@@ -67,7 +67,7 @@ Some database systems may allow a connection to switch to a different `db.user`,
 | `db.system` | string | An identifier for the database management system (DBMS) product being used. See below for a list of well-known identifiers. | `other_sql` | Required |
 | `db.connection_string` | string | The connection string used to connect to the database. It is recommended to remove embedded credentials. | `Server=(localdb)\v11.0;Integrated Security=true;` | Recommended |
 | `db.user` | string | Username for accessing the database. | `readonly_user`; `reporting_user` | Recommended |
-| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. | `tcp`; `udp` | Recommended |
+| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. Consider always setting the transport when setting a port number, since a port number is ambiguous without knowing the transport, for example different processes could be listening on TCP port 12345 and UDP port 12345. | `tcp`; `udp` | Recommended |
 | [`network.type`](../general/attributes.md) | string | [OSI Network Layer](https://osi-model.com/network-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `ipv4`; `ipv6` | Recommended |
 | [`server.address`](../general/attributes.md) | string | Name of the database host. [1] | `example.com` | Conditionally Required: See alternative attributes below. |
 | [`server.port`](../general/attributes.md) | int | Server port number [2] | `80`; `8080`; `443` | Conditionally Required: [3] |

docs/general/attributes.md

@@ -15,25 +15,29 @@ Particular operations may refer to or require some of these attributes.
 
 <!-- toc -->
 
-- [Server and client attributes](#server-and-client-attributes)
+- [Server, client and shared network attributes](#server-client-and-shared-network-attributes)
+  * [Address and port attributes](#address-and-port-attributes)
   * [Server attributes](#server-attributes)
     + [`server.address`](#serveraddress)
     + [`server.socket.*` attributes](#serversocket-attributes)
   * [Client attributes](#client-attributes)
     + [Connecting through intermediary](#connecting-through-intermediary)
-- [Network attributes](#network-attributes)
   * [Source and destination attributes](#source-and-destination-attributes)
     + [Source](#source)
     + [Destination](#destination)
-  * [Network connection and carrier attributes](#network-connection-and-carrier-attributes)
+  * [Other network attributes](#other-network-attributes)
+    + [Network connection and carrier attributes](#network-connection-and-carrier-attributes)
 - [General remote service attributes](#general-remote-service-attributes)
 - [General identity attributes](#general-identity-attributes)
 - [General thread attributes](#general-thread-attributes)
 - [Source Code Attributes](#source-code-attributes)
 
 <!-- tocstop -->
 
-## Server and client attributes
+<!-- Keep old anchor IDs -->
+<a name="server-and-client-attributes"></a>
+
+## Server, client and shared network attributes
 
 These attributes may be used to describe the client and server in a connection-based network interaction
 where there is one side that initiates the connection (the client is the side that initiates the connection).
@@ -45,6 +49,13 @@ This also covers UDP network interactions where one side initiates the interacti
 In an ideal situation, not accounting for proxies, multiple IP addresses or host names,
 the `server.*` attributes are the same on the client and server.
 
+### Address and port attributes
+
+For all IP-based protocols, the "address" should be just the IP-level address.
+Protocol-specific parts of an address are split into other attributes (when applicable) such as "port" attributes for
+TCP and UDP. If such transport-specific information is collected and the attribute name does not already uniquely
+identify the transport, then setting [`network.transport`](#other-network-attributes) is especially encouraged.
+
 ### Server attributes
 
 > **Warning**
@@ -175,40 +186,6 @@ The `client.socket.address` and `client.socket.port` attributes then SHOULD cont
 
 If only immediate peer information is available, it should be set on `client.address` and `client.port` and `client.socket.*` attributes SHOULD NOT be set.
 
-## Network attributes
-
-> **Warning**
-> Attributes in this section are in use by the HTTP semantic conventions.
-Once the HTTP semantic conventions are declared stable, changes to the attributes in this section will only be allowed
-if they do not cause breaking changes to HTTP semantic conventions.
-
-<!-- semconv network-core -->
-| Attribute  | Type | Description  | Examples  | Requirement Level |
-|---|---|---|---|---|
-| `network.transport` | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. | `tcp`; `udp` | Recommended |
-| `network.type` | string | [OSI Network Layer](https://osi-model.com/network-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `ipv4`; `ipv6` | Recommended |
-| `network.protocol.name` | string | [OSI Application Layer](https://osi-model.com/application-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `amqp`; `http`; `mqtt` | Recommended |
-| `network.protocol.version` | string | Version of the application layer protocol used. See note below. [1] | `3.1.1` | Recommended |
-
-**[1]:** `network.protocol.version` refers to the version of the protocol used and might be different from the protocol client's version. If the HTTP client used has a version of `0.27.2`, but sends HTTP version `1.1`, this attribute should be set to `1.1`.
-
-`network.transport` has the following list of well-known values. If one of them applies, then the respective value MUST be used, otherwise a custom value MAY be used.
-
-| Value  | Description |
-|---|---|
-| `tcp` | TCP |
-| `udp` | UDP |
-| `pipe` | Named or anonymous pipe. See note below. |
-| `unix` | Unix domain socket |
-
-`network.type` has the following list of well-known values. If one of them applies, then the respective value MUST be used, otherwise a custom value MAY be used.
-
-| Value  | Description |
-|---|---|
-| `ipv4` | IPv4 |
-| `ipv6` | IPv6 |
-<!-- endsemconv -->
-
 ### Source and destination attributes
 
 These attributes may be used to describe the sender and receiver of a network exchange/packet. These should be used
@@ -244,7 +221,43 @@ Destination fields capture details about the receiver of a network exchange/pack
 **[1]:** This value may be a host name, a fully qualified domain name, or another host naming format.
 <!-- endsemconv -->
 
-### Network connection and carrier attributes
+<a name="network-attributes"></a>
+
+### Other network attributes
+
+> **Warning**
+> Attributes in this section are in use by the HTTP semantic conventions.
+Once the HTTP semantic conventions are declared stable, changes to the attributes in this section will only be allowed
+if they do not cause breaking changes to HTTP semantic conventions.
+
+<!-- semconv network-core -->
+| Attribute  | Type | Description  | Examples  | Requirement Level |
+|---|---|---|---|---|
+| `network.transport` | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. Consider always setting the transport when setting a port number, since a port number is ambiguous without knowing the transport, for example different processes could be listening on TCP port 12345 and UDP port 12345. | `tcp`; `udp` | Recommended |
+| `network.type` | string | [OSI Network Layer](https://osi-model.com/network-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `ipv4`; `ipv6` | Recommended |
+| `network.protocol.name` | string | [OSI Application Layer](https://osi-model.com/application-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `amqp`; `http`; `mqtt` | Recommended |
+| `network.protocol.version` | string | Version of the application layer protocol used. See note below. [1] | `3.1.1` | Recommended |
+
+**[1]:** `network.protocol.version` refers to the version of the protocol used and might be different from the protocol client's version. If the HTTP client used has a version of `0.27.2`, but sends HTTP version `1.1`, this attribute should be set to `1.1`.
+
+`network.transport` has the following list of well-known values. If one of them applies, then the respective value MUST be used, otherwise a custom value MAY be used.
+
+| Value  | Description |
+|---|---|
+| `tcp` | TCP |
+| `udp` | UDP |
+| `pipe` | Named or anonymous pipe. See note below. |
+| `unix` | Unix domain socket |
+
+`network.type` has the following list of well-known values. If one of them applies, then the respective value MUST be used, otherwise a custom value MAY be used.
+
+| Value  | Description |
+|---|---|
+| `ipv4` | IPv4 |
+| `ipv6` | IPv6 |
+<!-- endsemconv -->
+
+#### Network connection and carrier attributes
 
 <!-- semconv network-connection-and-carrier -->
 | Attribute  | Type | Description  | Examples  | Requirement Level |

docs/http/http-spans.md

@@ -104,7 +104,7 @@ sections below.
 | `http.request.method` | string | HTTP request method. [2] | `GET`; `POST`; `HEAD` | Required |
 | [`network.protocol.name`](../general/attributes.md) | string | [OSI Application Layer](https://osi-model.com/application-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `http`; `spdy` | Recommended: if not default (`http`). |
 | [`network.protocol.version`](../general/attributes.md) | string | Version of the application layer protocol used. See note below. [3] | `1.0`; `1.1`; `2`; `3` | Recommended |
-| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. | `tcp`; `udp` | Conditionally Required: [4] |
+| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. Consider always setting the transport when setting a port number, since a port number is ambiguous without knowing the transport, for example different processes could be listening on TCP port 12345 and UDP port 12345. | `tcp`; `udp` | Conditionally Required: [4] |
 | [`network.type`](../general/attributes.md) | string | [OSI Network Layer](https://osi-model.com/network-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `ipv4`; `ipv6` | Recommended |
 | `user_agent.original` | string | Value of the [HTTP User-Agent](https://www.rfc-editor.org/rfc/rfc9110.html#field.user-agent) header sent by the client. | `CERN-LineMode/2.15 libwww/2.17b3` | Recommended |
 

docs/messaging/messaging-spans.md

@@ -231,7 +231,7 @@ The following operations related to messages are defined for these semantic conv
 | `messaging.message.payload_size_bytes` | int | The (uncompressed) size of the message payload in bytes. Also use this attribute if it is unknown whether the compressed or uncompressed payload size is reported. | `2738` | Recommended: [13] |
 | [`network.protocol.name`](../general/attributes.md) | string | [OSI Application Layer](https://osi-model.com/application-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `amqp`; `mqtt` | Recommended |
 | [`network.protocol.version`](../general/attributes.md) | string | Version of the application layer protocol used. See note below. [14] | `3.1.1` | Recommended |
-| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. | `tcp`; `udp` | Recommended |
+| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. Consider always setting the transport when setting a port number, since a port number is ambiguous without knowing the transport, for example different processes could be listening on TCP port 12345 and UDP port 12345. | `tcp`; `udp` | Recommended |
 | [`network.type`](../general/attributes.md) | string | [OSI Network Layer](https://osi-model.com/network-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `ipv4`; `ipv6` | Recommended |
 | [`server.address`](../general/attributes.md) | string | Server address - domain name if available without reverse DNS lookup, otherwise IP address or Unix domain socket name. [15] | `example.com` | Conditionally Required: If available. |
 | [`server.socket.address`](../general/attributes.md) | string | Server address of the socket connection - IP address or Unix domain socket name. [16] | `10.5.3.2` | Recommended: If different than `server.address`. |

docs/rpc/rpc-metrics.md

@@ -195,7 +195,7 @@ measurements.
 | [`rpc.system`](rpc-spans.md) | string | A string identifying the remoting system. See below for a list of well-known identifiers. | `grpc` | Required |
 | [`rpc.service`](rpc-spans.md) | string | The full (logical) name of the service being called, including its package name, if applicable. [1] | `myservice.EchoService` | Recommended |
 | [`rpc.method`](rpc-spans.md) | string | The name of the (logical) method being called, must be equal to the $method part in the span name. [2] | `exampleMethod` | Recommended |
-| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. | `tcp`; `udp` | Recommended |
+| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. Consider always setting the transport when setting a port number, since a port number is ambiguous without knowing the transport, for example different processes could be listening on TCP port 12345 and UDP port 12345. | `tcp`; `udp` | Recommended |
 | [`network.type`](../general/attributes.md) | string | [OSI Network Layer](https://osi-model.com/network-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `ipv4`; `ipv6` | Recommended |
 | [`server.address`](../general/attributes.md) | string | RPC server [host name](https://grpc.github.io/grpc/core/md_doc_naming.html). [3] | `example.com` | Required |
 | [`server.port`](../general/attributes.md) | int | Server port number [4] | `80`; `8080`; `443` | Conditionally Required: See below |

docs/rpc/rpc-spans.md

@@ -88,7 +88,7 @@ Examples of span names:
 | `rpc.system` | string | A string identifying the remoting system. See below for a list of well-known identifiers. | `grpc` | Required |
 | `rpc.service` | string | The full (logical) name of the service being called, including its package name, if applicable. [1] | `myservice.EchoService` | Recommended |
 | `rpc.method` | string | The name of the (logical) method being called, must be equal to the $method part in the span name. [2] | `exampleMethod` | Recommended |
-| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. | `tcp`; `udp` | Recommended |
+| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. Consider always setting the transport when setting a port number, since a port number is ambiguous without knowing the transport, for example different processes could be listening on TCP port 12345 and UDP port 12345. | `tcp`; `udp` | Recommended |
 | [`network.type`](../general/attributes.md) | string | [OSI Network Layer](https://osi-model.com/network-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `ipv4`; `ipv6` | Recommended |
 | [`server.address`](../general/attributes.md) | string | RPC server [host name](https://grpc.github.io/grpc/core/md_doc_naming.html). [3] | `example.com` | Required |
 | [`server.port`](../general/attributes.md) | int | Server port number [4] | `80`; `8080`; `443` | Conditionally Required: See below |
@@ -165,7 +165,7 @@ Generally, a user SHOULD NOT set `peer.service` to a fully qualified RPC service
 | [`client.port`](../general/attributes.md) | int | Client port number. [2] | `65123` | Recommended |
 | [`client.socket.address`](../general/attributes.md) | string | Client address of the socket connection - IP address or Unix domain socket name. [3] | `/tmp/my.sock`; `127.0.0.1` | Recommended: If different than `client.address`. |
 | [`client.socket.port`](../general/attributes.md) | int | Client port number of the socket connection. [4] | `35555` | Recommended: If different than `client.port`. |
-| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. | `tcp`; `udp` | Recommended |
+| [`network.transport`](../general/attributes.md) | string | [OSI Transport Layer](https://osi-model.com/transport-layer/) or [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication). The value SHOULD be normalized to lowercase. Consider always setting the transport when setting a port number, since a port number is ambiguous without knowing the transport, for example different processes could be listening on TCP port 12345 and UDP port 12345. | `tcp`; `udp` | Recommended |
 | [`network.type`](../general/attributes.md) | string | [OSI Network Layer](https://osi-model.com/network-layer/) or non-OSI equivalent. The value SHOULD be normalized to lowercase. | `ipv4`; `ipv6` | Recommended |
 
 **[1]:** When observed from the server side, and when communicating through an intermediary, `client.address` SHOULD represent the client address behind any intermediaries (e.g. proxies) if it's available.

model/network.yaml

@@ -25,6 +25,9 @@ groups:
           [OSI Transport Layer](https://osi-model.com/transport-layer/) or
           [Inter-process Communication method](https://en.wikipedia.org/wiki/Inter-process_communication).
           The value SHOULD be normalized to lowercase.
+          Consider always setting the transport when setting a port number, since
+          a port number is ambiguous without knowing the transport, for example
+          different processes could be listening on TCP port 12345 and UDP port 12345.
         examples: ['tcp', 'udp']
       - id: type
         type: