diff --git a/javascript/sentry-conventions/src/attributes.ts b/javascript/sentry-conventions/src/attributes.ts
index 1a494122..86756659 100644
--- a/javascript/sentry-conventions/src/attributes.ts
+++ b/javascript/sentry-conventions/src/attributes.ts
@@ -1633,6 +1633,52 @@ export const CODE_NAMESPACE = 'code.namespace';
  */
 export type CODE_NAMESPACE_TYPE = string;
 
+// Path: model/attributes/connectionType.json
+
+/**
+ * Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc). `connectionType`
+ *
+ * Attribute Value Type: `string` {@link CONNECTIONTYPE_TYPE}
+ *
+ * Contains PII: maybe
+ *
+ * Attribute defined in OTEL: No
+ *
+ * Aliases: {@link NETWORK_CONNECTION_TYPE} `network.connection.type`
+ *
+ * @deprecated Use {@link NETWORK_CONNECTION_TYPE} (network.connection.type) instead - Old namespace-less attribute, to be replaced with network.connection.type for span-first future
+ * @example "wifi"
+ */
+export const CONNECTIONTYPE = 'connectionType';
+
+/**
+ * Type for {@link CONNECTIONTYPE} connectionType
+ */
+export type CONNECTIONTYPE_TYPE = string;
+
+// Path: model/attributes/connection/connection__rtt.json
+
+/**
+ * Specifies the estimated effective round-trip time of the current connection, in milliseconds. `connection.rtt`
+ *
+ * Attribute Value Type: `number` {@link CONNECTION_RTT_TYPE}
+ *
+ * Contains PII: maybe
+ *
+ * Attribute defined in OTEL: No
+ *
+ * Aliases: {@link NETWORK_CONNECTION_RTT} `network.connection.rtt`
+ *
+ * @deprecated Use {@link NETWORK_CONNECTION_RTT} (network.connection.rtt) instead - Old attribute name (no official namespace), to be replaced with network.connection.rtt for span-first future
+ * @example 100
+ */
+export const CONNECTION_RTT = 'connection.rtt';
+
+/**
+ * Type for {@link CONNECTION_RTT} connection.rtt
+ */
+export type CONNECTION_RTT_TYPE = number;
+
 // Path: model/attributes/culture/culture__calendar.json
 
 /**
@@ -2183,6 +2229,29 @@ export const DEVICE_MODEL = 'device.model';
  */
 export type DEVICE_MODEL_TYPE = string;
 
+// Path: model/attributes/effectiveConnectionType.json
+
+/**
+ * Specifies the estimated effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g). `effectiveConnectionType`
+ *
+ * Attribute Value Type: `string` {@link EFFECTIVECONNECTIONTYPE_TYPE}
+ *
+ * Contains PII: maybe
+ *
+ * Attribute defined in OTEL: No
+ *
+ * Aliases: {@link NETWORK_CONNECTION_EFFECTIVE_TYPE} `network.connection.effective_type`
+ *
+ * @deprecated Use {@link NETWORK_CONNECTION_EFFECTIVE_TYPE} (network.connection.effective_type) instead - Old namespace-less attribute, to be replaced with network.connection.effective_type for span-first future
+ * @example "4g"
+ */
+export const EFFECTIVECONNECTIONTYPE = 'effectiveConnectionType';
+
+/**
+ * Type for {@link EFFECTIVECONNECTIONTYPE} effectiveConnectionType
+ */
+export type EFFECTIVECONNECTIONTYPE_TYPE = string;
+
 // Path: model/attributes/environment.json
 
 /**
@@ -6007,6 +6076,72 @@ export const NEL_TYPE = 'nel.type';
  */
 export type NEL_TYPE_TYPE = string;
 
+// Path: model/attributes/network/network__connection__effective_type.json
+
+/**
+ * Specifies the effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g). `network.connection.effective_type`
+ *
+ * Attribute Value Type: `string` {@link NETWORK_CONNECTION_EFFECTIVE_TYPE_TYPE}
+ *
+ * Contains PII: maybe
+ *
+ * Attribute defined in OTEL: No
+ *
+ * Aliases: {@link EFFECTIVECONNECTIONTYPE} `effectiveConnectionType`
+ *
+ * @example "4g"
+ */
+export const NETWORK_CONNECTION_EFFECTIVE_TYPE = 'network.connection.effective_type';
+
+/**
+ * Type for {@link NETWORK_CONNECTION_EFFECTIVE_TYPE} network.connection.effective_type
+ */
+export type NETWORK_CONNECTION_EFFECTIVE_TYPE_TYPE = string;
+
+// Path: model/attributes/network/network__connection__rtt.json
+
+/**
+ * Specifies the estimated effective round-trip time of the current connection, in milliseconds. `network.connection.rtt`
+ *
+ * Attribute Value Type: `number` {@link NETWORK_CONNECTION_RTT_TYPE}
+ *
+ * Contains PII: maybe
+ *
+ * Attribute defined in OTEL: No
+ *
+ * Aliases: {@link CONNECTION_RTT} `connection.rtt`
+ *
+ * @example 100
+ */
+export const NETWORK_CONNECTION_RTT = 'network.connection.rtt';
+
+/**
+ * Type for {@link NETWORK_CONNECTION_RTT} network.connection.rtt
+ */
+export type NETWORK_CONNECTION_RTT_TYPE = number;
+
+// Path: model/attributes/network/network__connection__type.json
+
+/**
+ * Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc). `network.connection.type`
+ *
+ * Attribute Value Type: `string` {@link NETWORK_CONNECTION_TYPE_TYPE}
+ *
+ * Contains PII: maybe
+ *
+ * Attribute defined in OTEL: Yes
+ *
+ * Aliases: {@link CONNECTIONTYPE} `connectionType`
+ *
+ * @example "wifi"
+ */
+export const NETWORK_CONNECTION_TYPE = 'network.connection.type';
+
+/**
+ * Type for {@link NETWORK_CONNECTION_TYPE} network.connection.type
+ */
+export type NETWORK_CONNECTION_TYPE_TYPE = string;
+
 // Path: model/attributes/network/network__local__address.json
 
 /**
@@ -9917,6 +10052,8 @@ export const ATTRIBUTE_TYPE: Record<string, AttributeType> = {
   [CODE_LINENO]: 'integer',
   [CODE_LINE_NUMBER]: 'integer',
   [CODE_NAMESPACE]: 'string',
+  [CONNECTIONTYPE]: 'string',
+  [CONNECTION_RTT]: 'integer',
   [CULTURE_CALENDAR]: 'string',
   [CULTURE_DISPLAY_NAME]: 'string',
   [CULTURE_IS_24_HOUR_FORMAT]: 'boolean',
@@ -9943,6 +10080,7 @@ export const ATTRIBUTE_TYPE: Record<string, AttributeType> = {
   [DEVICE_FAMILY]: 'string',
   [DEVICE_MEMORY_ESTIMATED_CAPACITY]: 'integer',
   [DEVICE_MODEL]: 'string',
+  [EFFECTIVECONNECTIONTYPE]: 'string',
   [ENVIRONMENT]: 'string',
   [ERROR_TYPE]: 'string',
   [EVENT_ID]: 'integer',
@@ -10126,6 +10264,9 @@ export const ATTRIBUTE_TYPE: Record<string, AttributeType> = {
   [NEL_REFERRER]: 'string',
   [NEL_SAMPLING_FUNCTION]: 'double',
   [NEL_TYPE]: 'string',
+  [NETWORK_CONNECTION_EFFECTIVE_TYPE]: 'string',
+  [NETWORK_CONNECTION_RTT]: 'integer',
+  [NETWORK_CONNECTION_TYPE]: 'string',
   [NETWORK_LOCAL_ADDRESS]: 'string',
   [NETWORK_LOCAL_PORT]: 'integer',
   [NETWORK_PEER_ADDRESS]: 'string',
@@ -10387,6 +10528,8 @@ export type AttributeName =
   | typeof CODE_LINENO
   | typeof CODE_LINE_NUMBER
   | typeof CODE_NAMESPACE
+  | typeof CONNECTIONTYPE
+  | typeof CONNECTION_RTT
   | typeof CULTURE_CALENDAR
   | typeof CULTURE_DISPLAY_NAME
   | typeof CULTURE_IS_24_HOUR_FORMAT
@@ -10413,6 +10556,7 @@ export type AttributeName =
   | typeof DEVICE_FAMILY
   | typeof DEVICE_MEMORY_ESTIMATED_CAPACITY
   | typeof DEVICE_MODEL
+  | typeof EFFECTIVECONNECTIONTYPE
   | typeof ENVIRONMENT
   | typeof ERROR_TYPE
   | typeof EVENT_ID
@@ -10596,6 +10740,9 @@ export type AttributeName =
   | typeof NEL_REFERRER
   | typeof NEL_SAMPLING_FUNCTION
   | typeof NEL_TYPE
+  | typeof NETWORK_CONNECTION_EFFECTIVE_TYPE
+  | typeof NETWORK_CONNECTION_RTT
+  | typeof NETWORK_CONNECTION_TYPE
   | typeof NETWORK_LOCAL_ADDRESS
   | typeof NETWORK_LOCAL_PORT
   | typeof NETWORK_PEER_ADDRESS
@@ -11790,6 +11937,51 @@ export const ATTRIBUTE_METADATA: Record<AttributeName, AttributeMetadata> = {
     },
     changelog: [{ version: '0.1.0', prs: [61, 74] }, { version: '0.0.0' }],
   },
+  [CONNECTIONTYPE]: {
+    brief: 'Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc).',
+    type: 'string',
+    pii: {
+      isPii: 'maybe',
+    },
+    isInOtel: false,
+    example: 'wifi',
+    deprecation: {
+      replacement: 'network.connection.type',
+      reason: 'Old namespace-less attribute, to be replaced with network.connection.type for span-first future',
+    },
+    aliases: [NETWORK_CONNECTION_TYPE],
+    sdks: ['javascript-browser'],
+    changelog: [
+      {
+        version: 'next',
+        prs: [279],
+        description: "Added and deprecated attribute to document JS SDK's current behaviour",
+      },
+    ],
+  },
+  [CONNECTION_RTT]: {
+    brief: 'Specifies the estimated effective round-trip time of the current connection, in milliseconds.',
+    type: 'integer',
+    pii: {
+      isPii: 'maybe',
+    },
+    isInOtel: false,
+    example: 100,
+    deprecation: {
+      replacement: 'network.connection.rtt',
+      reason:
+        'Old attribute name (no official namespace), to be replaced with network.connection.rtt for span-first future',
+    },
+    aliases: [NETWORK_CONNECTION_RTT],
+    sdks: ['javascript-browser'],
+    changelog: [
+      {
+        version: 'next',
+        prs: [279],
+        description: "Added and deprecated attribute to document JS SDK's current behaviour",
+      },
+    ],
+  },
   [CULTURE_CALENDAR]: {
     brief: 'The calendar system used by the culture.',
     type: 'string',
@@ -12114,6 +12306,29 @@ export const ATTRIBUTE_METADATA: Record<AttributeName, AttributeMetadata> = {
     example: 'iPhone 15 Pro Max',
     changelog: [{ version: '0.1.0', prs: [116, 127] }],
   },
+  [EFFECTIVECONNECTIONTYPE]: {
+    brief: 'Specifies the estimated effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g).',
+    type: 'string',
+    pii: {
+      isPii: 'maybe',
+    },
+    isInOtel: false,
+    example: '4g',
+    deprecation: {
+      replacement: 'network.connection.effective_type',
+      reason:
+        'Old namespace-less attribute, to be replaced with network.connection.effective_type for span-first future',
+    },
+    aliases: [NETWORK_CONNECTION_EFFECTIVE_TYPE],
+    sdks: ['javascript-browser'],
+    changelog: [
+      {
+        version: 'next',
+        prs: [279],
+        description: "Added and deprecated attribute to document JS SDK's current behaviour",
+      },
+    ],
+  },
   [ENVIRONMENT]: {
     brief: 'The sentry environment.',
     type: 'string',
@@ -14383,6 +14598,60 @@ export const ATTRIBUTE_METADATA: Record<AttributeName, AttributeMetadata> = {
     example: 'dns.unreachable',
     changelog: [{ version: '0.1.0', prs: [68, 127] }],
   },
+  [NETWORK_CONNECTION_EFFECTIVE_TYPE]: {
+    brief: 'Specifies the effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g).',
+    type: 'string',
+    pii: {
+      isPii: 'maybe',
+    },
+    isInOtel: false,
+    example: '4g',
+    aliases: [EFFECTIVECONNECTIONTYPE],
+    sdks: ['javascript-browser'],
+    changelog: [
+      {
+        version: 'next',
+        prs: [279],
+        description: 'Added attribute network.connection.effective_type to be used instead of effectiveConnectionType',
+      },
+    ],
+  },
+  [NETWORK_CONNECTION_RTT]: {
+    brief: 'Specifies the estimated effective round-trip time of the current connection, in milliseconds.',
+    type: 'integer',
+    pii: {
+      isPii: 'maybe',
+    },
+    isInOtel: false,
+    example: 100,
+    aliases: [CONNECTION_RTT],
+    sdks: ['javascript-browser'],
+    changelog: [
+      {
+        version: 'next',
+        prs: [279],
+        description: 'Added attribute network.connection.rtt to be used instead of connection.rtt',
+      },
+    ],
+  },
+  [NETWORK_CONNECTION_TYPE]: {
+    brief: 'Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc).',
+    type: 'string',
+    pii: {
+      isPii: 'maybe',
+    },
+    isInOtel: true,
+    example: 'wifi',
+    aliases: [CONNECTIONTYPE],
+    sdks: ['javascript-browser'],
+    changelog: [
+      {
+        version: 'next',
+        prs: [279],
+        description: 'Added attribute network.connection.type to be used instead of connectionType',
+      },
+    ],
+  },
   [NETWORK_LOCAL_ADDRESS]: {
     brief: 'Local address of the network connection - IP address or Unix domain socket name.',
     type: 'string',
@@ -16497,6 +16766,8 @@ export type Attributes = {
   [CODE_LINENO]?: CODE_LINENO_TYPE;
   [CODE_LINE_NUMBER]?: CODE_LINE_NUMBER_TYPE;
   [CODE_NAMESPACE]?: CODE_NAMESPACE_TYPE;
+  [CONNECTIONTYPE]?: CONNECTIONTYPE_TYPE;
+  [CONNECTION_RTT]?: CONNECTION_RTT_TYPE;
   [CULTURE_CALENDAR]?: CULTURE_CALENDAR_TYPE;
   [CULTURE_DISPLAY_NAME]?: CULTURE_DISPLAY_NAME_TYPE;
   [CULTURE_IS_24_HOUR_FORMAT]?: CULTURE_IS_24_HOUR_FORMAT_TYPE;
@@ -16523,6 +16794,7 @@ export type Attributes = {
   [DEVICE_FAMILY]?: DEVICE_FAMILY_TYPE;
   [DEVICE_MEMORY_ESTIMATED_CAPACITY]?: DEVICE_MEMORY_ESTIMATED_CAPACITY_TYPE;
   [DEVICE_MODEL]?: DEVICE_MODEL_TYPE;
+  [EFFECTIVECONNECTIONTYPE]?: EFFECTIVECONNECTIONTYPE_TYPE;
   [ENVIRONMENT]?: ENVIRONMENT_TYPE;
   [ERROR_TYPE]?: ERROR_TYPE_TYPE;
   [EVENT_ID]?: EVENT_ID_TYPE;
@@ -16706,6 +16978,9 @@ export type Attributes = {
   [NEL_REFERRER]?: NEL_REFERRER_TYPE;
   [NEL_SAMPLING_FUNCTION]?: NEL_SAMPLING_FUNCTION_TYPE;
   [NEL_TYPE]?: NEL_TYPE_TYPE;
+  [NETWORK_CONNECTION_EFFECTIVE_TYPE]?: NETWORK_CONNECTION_EFFECTIVE_TYPE_TYPE;
+  [NETWORK_CONNECTION_RTT]?: NETWORK_CONNECTION_RTT_TYPE;
+  [NETWORK_CONNECTION_TYPE]?: NETWORK_CONNECTION_TYPE_TYPE;
   [NETWORK_LOCAL_ADDRESS]?: NETWORK_LOCAL_ADDRESS_TYPE;
   [NETWORK_LOCAL_PORT]?: NETWORK_LOCAL_PORT_TYPE;
   [NETWORK_PEER_ADDRESS]?: NETWORK_PEER_ADDRESS_TYPE;
diff --git a/model/attributes/connection/connection__rtt.json b/model/attributes/connection/connection__rtt.json
new file mode 100644
index 00000000..9a2e1d9b
--- /dev/null
+++ b/model/attributes/connection/connection__rtt.json
@@ -0,0 +1,24 @@
+{
+  "key": "connection.rtt",
+  "brief": "Specifies the estimated effective round-trip time of the current connection, in milliseconds.",
+  "type": "integer",
+  "pii": {
+    "key": "maybe"
+  },
+  "is_in_otel": false,
+  "example": 100,
+  "sdks": ["javascript-browser"],
+  "alias": ["network.connection.rtt"],
+  "deprecation": {
+    "replacement": "network.connection.rtt",
+    "reason": "Old attribute name (no official namespace), to be replaced with network.connection.rtt for span-first future",
+    "_status": "backfill"
+  },
+  "changelog": [
+    {
+      "version": "next",
+      "prs": [279],
+      "description": "Added and deprecated attribute to document JS SDK's current behaviour"
+    }
+  ]
+}
diff --git a/model/attributes/connectionType.json b/model/attributes/connectionType.json
new file mode 100644
index 00000000..1a97a362
--- /dev/null
+++ b/model/attributes/connectionType.json
@@ -0,0 +1,24 @@
+{
+  "key": "connectionType",
+  "brief": "Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc).",
+  "type": "string",
+  "pii": {
+    "key": "maybe"
+  },
+  "is_in_otel": false,
+  "example": "wifi",
+  "sdks": ["javascript-browser"],
+  "alias": ["network.connection.type"],
+  "deprecation": {
+    "replacement": "network.connection.type",
+    "reason": "Old namespace-less attribute, to be replaced with network.connection.type for span-first future",
+    "_status": "backfill"
+  },
+  "changelog": [
+    {
+      "version": "next",
+      "prs": [279],
+      "description": "Added and deprecated attribute to document JS SDK's current behaviour"
+    }
+  ]
+}
diff --git a/model/attributes/effectiveConnectionType.json b/model/attributes/effectiveConnectionType.json
new file mode 100644
index 00000000..1b074e7c
--- /dev/null
+++ b/model/attributes/effectiveConnectionType.json
@@ -0,0 +1,24 @@
+{
+  "key": "effectiveConnectionType",
+  "brief": "Specifies the estimated effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g).",
+  "type": "string",
+  "pii": {
+    "key": "maybe"
+  },
+  "is_in_otel": false,
+  "example": "4g",
+  "sdks": ["javascript-browser"],
+  "alias": ["network.connection.effective_type"],
+  "deprecation": {
+    "replacement": "network.connection.effective_type",
+    "reason": "Old namespace-less attribute, to be replaced with network.connection.effective_type for span-first future",
+    "_status": "backfill"
+  },
+  "changelog": [
+    {
+      "version": "next",
+      "prs": [279],
+      "description": "Added and deprecated attribute to document JS SDK's current behaviour"
+    }
+  ]
+}
diff --git a/model/attributes/network/network__connection__effective_type.json b/model/attributes/network/network__connection__effective_type.json
new file mode 100644
index 00000000..514dea94
--- /dev/null
+++ b/model/attributes/network/network__connection__effective_type.json
@@ -0,0 +1,19 @@
+{
+  "key": "network.connection.effective_type",
+  "brief": "Specifies the effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g).",
+  "type": "string",
+  "pii": {
+    "key": "maybe"
+  },
+  "is_in_otel": false,
+  "example": "4g",
+  "alias": ["effectiveConnectionType"],
+  "sdks": ["javascript-browser"],
+  "changelog": [
+    {
+      "version": "next",
+      "prs": [279],
+      "description": "Added attribute network.connection.effective_type to be used instead of effectiveConnectionType"
+    }
+  ]
+}
diff --git a/model/attributes/network/network__connection__rtt.json b/model/attributes/network/network__connection__rtt.json
new file mode 100644
index 00000000..840a0f42
--- /dev/null
+++ b/model/attributes/network/network__connection__rtt.json
@@ -0,0 +1,19 @@
+{
+  "key": "network.connection.rtt",
+  "brief": "Specifies the estimated effective round-trip time of the current connection, in milliseconds.",
+  "type": "integer",
+  "pii": {
+    "key": "maybe"
+  },
+  "is_in_otel": false,
+  "example": 100,
+  "alias": ["connection.rtt"],
+  "sdks": ["javascript-browser"],
+  "changelog": [
+    {
+      "version": "next",
+      "prs": [279],
+      "description": "Added attribute network.connection.rtt to be used instead of connection.rtt"
+    }
+  ]
+}
diff --git a/model/attributes/network/network__connection__type.json b/model/attributes/network/network__connection__type.json
new file mode 100644
index 00000000..aa317812
--- /dev/null
+++ b/model/attributes/network/network__connection__type.json
@@ -0,0 +1,19 @@
+{
+  "key": "network.connection.type",
+  "brief": "Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc).",
+  "type": "string",
+  "pii": {
+    "key": "maybe"
+  },
+  "is_in_otel": true,
+  "example": "wifi",
+  "alias": ["connectionType"],
+  "sdks": ["javascript-browser"],
+  "changelog": [
+    {
+      "version": "next",
+      "prs": [279],
+      "description": "Added attribute network.connection.type to be used instead of connectionType"
+    }
+  ]
+}
diff --git a/python/src/sentry_conventions/attributes.py b/python/src/sentry_conventions/attributes.py
index ed893549..01ebb425 100644
--- a/python/src/sentry_conventions/attributes.py
+++ b/python/src/sentry_conventions/attributes.py
@@ -142,12 +142,15 @@ class _AttributeNamesMeta(type):
         "CODE_FUNCTION",
         "CODE_LINENO",
         "CODE_NAMESPACE",
+        "CONNECTION_RTT",
+        "CONNECTIONTYPE",
         "DB_NAME",
         "DB_OPERATION",
         "DB_SQL_BINDINGS",
         "DB_STATEMENT",
         "DB_SYSTEM",
         "DEVICEMEMORY",
+        "EFFECTIVECONNECTIONTYPE",
         "ENVIRONMENT",
         "FCP",
         "FP",
@@ -1106,6 +1109,30 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
     Example: "http.handler"
     """
 
+    # Path: model/attributes/connection/connection__rtt.json
+    CONNECTION_RTT: Literal["connection.rtt"] = "connection.rtt"
+    """Specifies the estimated effective round-trip time of the current connection, in milliseconds.
+
+    Type: int
+    Contains PII: maybe
+    Defined in OTEL: No
+    Aliases: network.connection.rtt
+    DEPRECATED: Use network.connection.rtt instead - Old attribute name (no official namespace), to be replaced with network.connection.rtt for span-first future
+    Example: 100
+    """
+
+    # Path: model/attributes/connectionType.json
+    CONNECTIONTYPE: Literal["connectionType"] = "connectionType"
+    """Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc).
+
+    Type: str
+    Contains PII: maybe
+    Defined in OTEL: No
+    Aliases: network.connection.type
+    DEPRECATED: Use network.connection.type instead - Old namespace-less attribute, to be replaced with network.connection.type for span-first future
+    Example: "wifi"
+    """
+
     # Path: model/attributes/culture/culture__calendar.json
     CULTURE_CALENDAR: Literal["culture.calendar"] = "culture.calendar"
     """The calendar system used by the culture.
@@ -1392,6 +1419,20 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
     Example: "8 GB"
     """
 
+    # Path: model/attributes/effectiveConnectionType.json
+    EFFECTIVECONNECTIONTYPE: Literal["effectiveConnectionType"] = (
+        "effectiveConnectionType"
+    )
+    """Specifies the estimated effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g).
+
+    Type: str
+    Contains PII: maybe
+    Defined in OTEL: No
+    Aliases: network.connection.effective_type
+    DEPRECATED: Use network.connection.effective_type instead - Old namespace-less attribute, to be replaced with network.connection.effective_type for span-first future
+    Example: "4g"
+    """
+
     # Path: model/attributes/environment.json
     ENVIRONMENT: Literal["environment"] = "environment"
     """The sentry environment.
@@ -3638,6 +3679,43 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
     Example: "tcp"
     """
 
+    # Path: model/attributes/network/network__connection__effective_type.json
+    NETWORK_CONNECTION_EFFECTIVE_TYPE: Literal["network.connection.effective_type"] = (
+        "network.connection.effective_type"
+    )
+    """Specifies the effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g).
+
+    Type: str
+    Contains PII: maybe
+    Defined in OTEL: No
+    Aliases: effectiveConnectionType
+    Example: "4g"
+    """
+
+    # Path: model/attributes/network/network__connection__rtt.json
+    NETWORK_CONNECTION_RTT: Literal["network.connection.rtt"] = "network.connection.rtt"
+    """Specifies the estimated effective round-trip time of the current connection, in milliseconds.
+
+    Type: int
+    Contains PII: maybe
+    Defined in OTEL: No
+    Aliases: connection.rtt
+    Example: 100
+    """
+
+    # Path: model/attributes/network/network__connection__type.json
+    NETWORK_CONNECTION_TYPE: Literal["network.connection.type"] = (
+        "network.connection.type"
+    )
+    """Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc).
+
+    Type: str
+    Contains PII: maybe
+    Defined in OTEL: Yes
+    Aliases: connectionType
+    Example: "wifi"
+    """
+
     # Path: model/attributes/network/network__local__address.json
     NETWORK_LOCAL_ADDRESS: Literal["network.local.address"] = "network.local.address"
     """Local address of the network connection - IP address or Unix domain socket name.
@@ -6387,6 +6465,48 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
             ChangelogEntry(version="0.0.0"),
         ],
     ),
+    "connection.rtt": AttributeMetadata(
+        brief="Specifies the estimated effective round-trip time of the current connection, in milliseconds.",
+        type=AttributeType.INTEGER,
+        pii=PiiInfo(isPii=IsPii.MAYBE),
+        is_in_otel=False,
+        example=100,
+        deprecation=DeprecationInfo(
+            replacement="network.connection.rtt",
+            reason="Old attribute name (no official namespace), to be replaced with network.connection.rtt for span-first future",
+            status=DeprecationStatus.BACKFILL,
+        ),
+        aliases=["network.connection.rtt"],
+        sdks=["javascript-browser"],
+        changelog=[
+            ChangelogEntry(
+                version="next",
+                prs=[279],
+                description="Added and deprecated attribute to document JS SDK's current behaviour",
+            ),
+        ],
+    ),
+    "connectionType": AttributeMetadata(
+        brief="Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc).",
+        type=AttributeType.STRING,
+        pii=PiiInfo(isPii=IsPii.MAYBE),
+        is_in_otel=False,
+        example="wifi",
+        deprecation=DeprecationInfo(
+            replacement="network.connection.type",
+            reason="Old namespace-less attribute, to be replaced with network.connection.type for span-first future",
+            status=DeprecationStatus.BACKFILL,
+        ),
+        aliases=["network.connection.type"],
+        sdks=["javascript-browser"],
+        changelog=[
+            ChangelogEntry(
+                version="next",
+                prs=[279],
+                description="Added and deprecated attribute to document JS SDK's current behaviour",
+            ),
+        ],
+    ),
     "culture.calendar": AttributeMetadata(
         brief="The calendar system used by the culture.",
         type=AttributeType.STRING,
@@ -6713,6 +6833,27 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
             ),
         ],
     ),
+    "effectiveConnectionType": AttributeMetadata(
+        brief="Specifies the estimated effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g).",
+        type=AttributeType.STRING,
+        pii=PiiInfo(isPii=IsPii.MAYBE),
+        is_in_otel=False,
+        example="4g",
+        deprecation=DeprecationInfo(
+            replacement="network.connection.effective_type",
+            reason="Old namespace-less attribute, to be replaced with network.connection.effective_type for span-first future",
+            status=DeprecationStatus.BACKFILL,
+        ),
+        aliases=["network.connection.effective_type"],
+        sdks=["javascript-browser"],
+        changelog=[
+            ChangelogEntry(
+                version="next",
+                prs=[279],
+                description="Added and deprecated attribute to document JS SDK's current behaviour",
+            ),
+        ],
+    ),
     "environment": AttributeMetadata(
         brief="The sentry environment.",
         type=AttributeType.STRING,
@@ -9118,6 +9259,54 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
             ChangelogEntry(version="0.0.0"),
         ],
     ),
+    "network.connection.effective_type": AttributeMetadata(
+        brief="Specifies the effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g).",
+        type=AttributeType.STRING,
+        pii=PiiInfo(isPii=IsPii.MAYBE),
+        is_in_otel=False,
+        example="4g",
+        aliases=["effectiveConnectionType"],
+        sdks=["javascript-browser"],
+        changelog=[
+            ChangelogEntry(
+                version="next",
+                prs=[279],
+                description="Added attribute network.connection.effective_type to be used instead of effectiveConnectionType",
+            ),
+        ],
+    ),
+    "network.connection.rtt": AttributeMetadata(
+        brief="Specifies the estimated effective round-trip time of the current connection, in milliseconds.",
+        type=AttributeType.INTEGER,
+        pii=PiiInfo(isPii=IsPii.MAYBE),
+        is_in_otel=False,
+        example=100,
+        aliases=["connection.rtt"],
+        sdks=["javascript-browser"],
+        changelog=[
+            ChangelogEntry(
+                version="next",
+                prs=[279],
+                description="Added attribute network.connection.rtt to be used instead of connection.rtt",
+            ),
+        ],
+    ),
+    "network.connection.type": AttributeMetadata(
+        brief="Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc).",
+        type=AttributeType.STRING,
+        pii=PiiInfo(isPii=IsPii.MAYBE),
+        is_in_otel=True,
+        example="wifi",
+        aliases=["connectionType"],
+        sdks=["javascript-browser"],
+        changelog=[
+            ChangelogEntry(
+                version="next",
+                prs=[279],
+                description="Added attribute network.connection.type to be used instead of connectionType",
+            ),
+        ],
+    ),
     "network.local.address": AttributeMetadata(
         brief="Local address of the network connection - IP address or Unix domain socket name.",
         type=AttributeType.STRING,
@@ -11059,6 +11248,8 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
         "code.line.number": int,
         "code.lineno": int,
         "code.namespace": str,
+        "connection.rtt": int,
+        "connectionType": str,
         "culture.calendar": str,
         "culture.display_name": str,
         "culture.is_24_hour_format": bool,
@@ -11085,6 +11276,7 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
         "device.memory.estimated_capacity": int,
         "device.model": str,
         "deviceMemory": str,
+        "effectiveConnectionType": str,
         "environment": str,
         "error.type": str,
         "event.id": int,
@@ -11283,6 +11475,9 @@ class ATTRIBUTE_NAMES(metaclass=_AttributeNamesMeta):
         "net.sock.peer.name": str,
         "net.sock.peer.port": int,
         "net.transport": str,
+        "network.connection.effective_type": str,
+        "network.connection.rtt": int,
+        "network.connection.type": str,
         "network.local.address": str,
         "network.local.port": int,
         "network.peer.address": str,
diff --git a/shared/deprecated_attributes.json b/shared/deprecated_attributes.json
index 9830d7fe..fba3c9a4 100644
--- a/shared/deprecated_attributes.json
+++ b/shared/deprecated_attributes.json
@@ -25,6 +25,30 @@
         }
       ]
     },
+    {
+      "key": "connectionType",
+      "brief": "Specifies the type of the current connection (e.g. wifi, ethernet, cellular , etc).",
+      "type": "string",
+      "pii": {
+        "key": "maybe"
+      },
+      "is_in_otel": false,
+      "example": "wifi",
+      "sdks": ["javascript-browser"],
+      "alias": ["network.connection.type"],
+      "deprecation": {
+        "replacement": "network.connection.type",
+        "reason": "Old namespace-less attribute, to be replaced with network.connection.type for span-first future",
+        "_status": "backfill"
+      },
+      "changelog": [
+        {
+          "version": "next",
+          "prs": [279],
+          "description": "Added and deprecated attribute to document JS SDK's current behaviour"
+        }
+      ]
+    },
     {
       "key": "deviceMemory",
       "brief": "The estimated total memory capacity of the device, only a rough estimation in gigabytes.",
@@ -49,6 +73,30 @@
         }
       ]
     },
+    {
+      "key": "effectiveConnectionType",
+      "brief": "Specifies the estimated effective type of the current connection (e.g. slow-2g, 2g, 3g, 4g).",
+      "type": "string",
+      "pii": {
+        "key": "maybe"
+      },
+      "is_in_otel": false,
+      "example": "4g",
+      "sdks": ["javascript-browser"],
+      "alias": ["network.connection.effective_type"],
+      "deprecation": {
+        "replacement": "network.connection.effective_type",
+        "reason": "Old namespace-less attribute, to be replaced with network.connection.effective_type for span-first future",
+        "_status": "backfill"
+      },
+      "changelog": [
+        {
+          "version": "next",
+          "prs": [279],
+          "description": "Added and deprecated attribute to document JS SDK's current behaviour"
+        }
+      ]
+    },
     {
       "key": "environment",
       "brief": "The sentry environment.",
@@ -1300,6 +1348,30 @@
         }
       ]
     },
+    {
+      "key": "connection.rtt",
+      "brief": "Specifies the estimated effective round-trip time of the current connection, in milliseconds.",
+      "type": "integer",
+      "pii": {
+        "key": "maybe"
+      },
+      "is_in_otel": false,
+      "example": 100,
+      "sdks": ["javascript-browser"],
+      "alias": ["network.connection.rtt"],
+      "deprecation": {
+        "replacement": "network.connection.rtt",
+        "reason": "Old attribute name (no official namespace), to be replaced with network.connection.rtt for span-first future",
+        "_status": "backfill"
+      },
+      "changelog": [
+        {
+          "version": "next",
+          "prs": [279],
+          "description": "Added and deprecated attribute to document JS SDK's current behaviour"
+        }
+      ]
+    },
     {
       "key": "db.name",
       "brief": "The name of the database being accessed.",