diff --git a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-replicaset.json b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-replicaset.json
new file mode 100644
index 0000000000..ccaea8d135
--- /dev/null
+++ b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-replicaset.json
@@ -0,0 +1,142 @@
+{
+  "description": "backpressure-network-error-fail-replicaset",
+  "schemaVersion": "1.17",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4",
+      "serverless": "forbid",
+      "topologies": [
+        "replicaset"
+      ]
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "setupClient",
+        "useMultipleMongoses": false
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "backpressure-network-error-fail",
+      "databaseName": "sdam-tests",
+      "documents": [
+        {
+          "_id": 1
+        },
+        {
+          "_id": 2
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "apply backpressure on network connection errors during connection establishment",
+      "operations": [
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client",
+                  "useMultipleMongoses": false,
+                  "observeEvents": [
+                    "serverDescriptionChangedEvent",
+                    "poolClearedEvent"
+                  ],
+                  "uriOptions": {
+                    "retryWrites": false,
+                    "heartbeatFrequencyMS": 1000000,
+                    "serverMonitoringMode": "poll",
+                    "appname": "backpressureNetworkErrorFailTest"
+                  }
+                }
+              },
+              {
+                "database": {
+                  "id": "database",
+                  "client": "client",
+                  "databaseName": "sdam-tests"
+                }
+              },
+              {
+                "collection": {
+                  "id": "collection",
+                  "database": "database",
+                  "collectionName": "backpressure-network-error-fail"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "waitForEvent",
+          "object": "testRunner",
+          "arguments": {
+            "client": "client",
+            "event": {
+              "serverDescriptionChangedEvent": {
+                "newDescription": {
+                  "type": "RSPrimary"
+                }
+              }
+            },
+            "count": 1
+          }
+        },
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "setupClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": "alwaysOn",
+              "data": {
+                "failCommands": [
+                  "isMaster",
+                  "hello"
+                ],
+                "appName": "backpressureNetworkErrorFailTest",
+                "closeConnection": true
+              }
+            }
+          }
+        },
+        {
+          "name": "insertMany",
+          "object": "collection",
+          "arguments": {
+            "documents": [
+              {
+                "_id": 3
+              },
+              {
+                "_id": 4
+              }
+            ]
+          },
+          "expectError": {
+            "isError": true,
+            "errorLabelsContain": [
+              "SystemOverloadedError",
+              "RetryableError"
+            ]
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "eventType": "cmap",
+          "events": []
+        }
+      ]
+    }
+  ]
+}
diff --git a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-replicaset.yml b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-replicaset.yml
new file mode 100644
index 0000000000..3aac5349be
--- /dev/null
+++ b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-replicaset.yml
@@ -0,0 +1,80 @@
+description: backpressure-network-error-fail-replicaset
+schemaVersion: "1.17"
+runOnRequirements:
+  - minServerVersion: "4.4"
+    serverless: forbid
+    topologies:
+      - replicaset
+createEntities:
+  - client:
+      id: setupClient
+      useMultipleMongoses: false
+initialData:
+  - collectionName: backpressure-network-error-fail
+    databaseName: sdam-tests
+    documents:
+      - _id: 1
+      - _id: 2
+tests:
+  - description: apply backpressure on network connection errors during connection establishment
+    operations:
+      - name: createEntities
+        object: testRunner
+        arguments:
+          entities:
+            - client:
+                id: client
+                useMultipleMongoses: false
+                observeEvents:
+                  - serverDescriptionChangedEvent
+                  - poolClearedEvent
+                uriOptions:
+                  retryWrites: false
+                  heartbeatFrequencyMS: 1000000
+                  serverMonitoringMode: poll
+                  appname: backpressureNetworkErrorFailTest
+            - database:
+                id: database
+                client: client
+                databaseName: sdam-tests
+            - collection:
+                id: collection
+                database: database
+                collectionName: backpressure-network-error-fail
+      - name: waitForEvent
+        object: testRunner
+        arguments:
+          client: client
+          event:
+            serverDescriptionChangedEvent:
+              newDescription:
+                type: RSPrimary
+          count: 1
+      - name: failPoint
+        object: testRunner
+        arguments:
+          client: setupClient
+          failPoint:
+            configureFailPoint: failCommand
+            mode: alwaysOn
+            data:
+              failCommands:
+                - isMaster
+                - hello
+              appName: backpressureNetworkErrorFailTest
+              closeConnection: true
+      - name: insertMany
+        object: collection
+        arguments:
+          documents:
+            - _id: 3
+            - _id: 4
+        expectError:
+          isError: true
+          errorLabelsContain:
+            - SystemOverloadedError
+            - RetryableError
+    expectEvents:
+      - client: client
+        eventType: cmap
+        events: []
diff --git a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail.json b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-single.json
similarity index 91%
rename from source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail.json
rename to source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-single.json
index f41b76459c..c1ff67c732 100644
--- a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail.json
+++ b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-single.json
@@ -1,14 +1,12 @@
 {
-  "description": "backpressure-network-error-fail",
+  "description": "backpressure-network-error-fail-single",
   "schemaVersion": "1.17",
   "runOnRequirements": [
     {
       "minServerVersion": "4.4",
       "serverless": "forbid",
       "topologies": [
-        "single",
-        "replicaset",
-        "sharded"
+        "single"
       ]
     }
   ],
@@ -48,7 +46,7 @@
                   "id": "client",
                   "useMultipleMongoses": false,
                   "observeEvents": [
-                    "serverHeartbeatSucceededEvent",
+                    "serverDescriptionChangedEvent",
                     "poolClearedEvent"
                   ],
                   "uriOptions": {
@@ -82,7 +80,11 @@
           "arguments": {
             "client": "client",
             "event": {
-              "serverHeartbeatSucceededEvent": {}
+              "serverDescriptionChangedEvent": {
+                "newDescription": {
+                  "type": "Standalone"
+                }
+              }
             },
             "count": 1
           }
diff --git a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail.yml b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-single.yml
similarity index 90%
rename from source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail.yml
rename to source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-single.yml
index 54e3030211..f5eebf2766 100644
--- a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail.yml
+++ b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-error-fail-single.yml
@@ -1,12 +1,10 @@
-description: backpressure-network-error-fail
+description: backpressure-network-error-fail-single
 schemaVersion: "1.17"
 runOnRequirements:
   - minServerVersion: "4.4"
     serverless: forbid
     topologies:
       - single
-      - replicaset
-      - sharded
 createEntities:
   - client:
       id: setupClient
@@ -28,7 +26,7 @@ tests:
                 id: client
                 useMultipleMongoses: false
                 observeEvents:
-                  - serverHeartbeatSucceededEvent
+                  - serverDescriptionChangedEvent
                   - poolClearedEvent
                 uriOptions:
                   retryWrites: false
@@ -48,7 +46,9 @@ tests:
         arguments:
           client: client
           event:
-            serverHeartbeatSucceededEvent: {}
+            serverDescriptionChangedEvent:
+              newDescription:
+                type: Standalone
           count: 1
       - name: failPoint
         object: testRunner
diff --git a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-replicaset.json b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-replicaset.json
new file mode 100644
index 0000000000..35b088f422
--- /dev/null
+++ b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-replicaset.json
@@ -0,0 +1,145 @@
+{
+  "description": "backpressure-network-timeout-error-replicaset",
+  "schemaVersion": "1.17",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4",
+      "serverless": "forbid",
+      "topologies": [
+        "replicaset"
+      ]
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "setupClient",
+        "useMultipleMongoses": false
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "backpressure-network-timeout-error",
+      "databaseName": "sdam-tests",
+      "documents": [
+        {
+          "_id": 1
+        },
+        {
+          "_id": 2
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "apply backpressure on network timeout error during connection establishment",
+      "operations": [
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client",
+                  "useMultipleMongoses": false,
+                  "observeEvents": [
+                    "serverDescriptionChangedEvent",
+                    "poolClearedEvent"
+                  ],
+                  "uriOptions": {
+                    "retryWrites": false,
+                    "heartbeatFrequencyMS": 1000000,
+                    "appname": "backpressureNetworkTimeoutErrorTest",
+                    "serverMonitoringMode": "poll",
+                    "connectTimeoutMS": 250,
+                    "socketTimeoutMS": 250
+                  }
+                }
+              },
+              {
+                "database": {
+                  "id": "database",
+                  "client": "client",
+                  "databaseName": "sdam-tests"
+                }
+              },
+              {
+                "collection": {
+                  "id": "collection",
+                  "database": "database",
+                  "collectionName": "backpressure-network-timeout-error"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "waitForEvent",
+          "object": "testRunner",
+          "arguments": {
+            "client": "client",
+            "event": {
+              "serverDescriptionChangedEvent": {
+                "newDescription": {
+                  "type": "RSPrimary"
+                }
+              }
+            },
+            "count": 1
+          }
+        },
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "setupClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": "alwaysOn",
+              "data": {
+                "failCommands": [
+                  "isMaster",
+                  "hello"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 500,
+                "appName": "backpressureNetworkTimeoutErrorTest"
+              }
+            }
+          }
+        },
+        {
+          "name": "insertMany",
+          "object": "collection",
+          "arguments": {
+            "documents": [
+              {
+                "_id": 3
+              },
+              {
+                "_id": 4
+              }
+            ]
+          },
+          "expectError": {
+            "isError": true,
+            "errorLabelsContain": [
+              "SystemOverloadedError",
+              "RetryableError"
+            ]
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "eventType": "cmap",
+          "events": []
+        }
+      ]
+    }
+  ]
+}
diff --git a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-replicaset.yml b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-replicaset.yml
new file mode 100644
index 0000000000..487872adc6
--- /dev/null
+++ b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-replicaset.yml
@@ -0,0 +1,83 @@
+description: backpressure-network-timeout-error-replicaset
+schemaVersion: "1.17"
+runOnRequirements:
+  - minServerVersion: "4.4"
+    serverless: forbid
+    topologies:
+      - replicaset
+createEntities:
+  - client:
+      id: setupClient
+      useMultipleMongoses: false
+initialData:
+  - collectionName: backpressure-network-timeout-error
+    databaseName: sdam-tests
+    documents:
+      - _id: 1
+      - _id: 2
+tests:
+  - description: apply backpressure on network timeout error during connection establishment
+    operations:
+      - name: createEntities
+        object: testRunner
+        arguments:
+          entities:
+            - client:
+                id: client
+                useMultipleMongoses: false
+                observeEvents:
+                  - serverDescriptionChangedEvent
+                  - poolClearedEvent
+                uriOptions:
+                  retryWrites: false
+                  heartbeatFrequencyMS: 1000000
+                  appname: backpressureNetworkTimeoutErrorTest
+                  serverMonitoringMode: poll
+                  connectTimeoutMS: 250
+                  socketTimeoutMS: 250
+            - database:
+                id: database
+                client: client
+                databaseName: sdam-tests
+            - collection:
+                id: collection
+                database: database
+                collectionName: backpressure-network-timeout-error
+      - name: waitForEvent
+        object: testRunner
+        arguments:
+          client: client
+          event:
+            serverDescriptionChangedEvent:
+              newDescription:
+                type: RSPrimary
+          count: 1
+      - name: failPoint
+        object: testRunner
+        arguments:
+          client: setupClient
+          failPoint:
+            configureFailPoint: failCommand
+            mode: alwaysOn
+            data:
+              failCommands:
+                - isMaster
+                - hello
+              blockConnection: true
+              blockTimeMS: 500
+              appName: backpressureNetworkTimeoutErrorTest
+      - name: insertMany
+        object: collection
+        arguments:
+          documents:
+            - _id: 3
+            - _id: 4
+        expectError:
+          isError: true
+          errorLabelsContain:
+            - SystemOverloadedError
+            - RetryableError
+    expectEvents:
+      - client: client
+        eventType: cmap
+        events: []
diff --git a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail.json b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-single.json
similarity index 93%
rename from source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail.json
rename to source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-single.json
index a97c7a329f..54b11d4d5b 100644
--- a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail.json
+++ b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-single.json
@@ -1,14 +1,12 @@
 {
-  "description": "backpressure-network-timeout-error",
+  "description": "backpressure-network-timeout-error-single",
   "schemaVersion": "1.17",
   "runOnRequirements": [
     {
       "minServerVersion": "4.4",
       "serverless": "forbid",
       "topologies": [
-        "single",
-        "replicaset",
-        "sharded"
+        "single"
       ]
     }
   ],
@@ -84,7 +82,11 @@
           "arguments": {
             "client": "client",
             "event": {
-              "serverDescriptionChangedEvent": {}
+              "serverDescriptionChangedEvent": {
+                "newDescription": {
+                  "type": "Standalone"
+                }
+              }
             },
             "count": 1
           }
diff --git a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail.yml b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-single.yml
similarity index 93%
rename from source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail.yml
rename to source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-single.yml
index 6a61eba3ad..6d94173174 100644
--- a/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail.yml
+++ b/source/server-discovery-and-monitoring/tests/unified/backpressure-network-timeout-fail-single.yml
@@ -1,12 +1,10 @@
-description: backpressure-network-timeout-error
+description: backpressure-network-timeout-error-single
 schemaVersion: "1.17"
 runOnRequirements:
   - minServerVersion: "4.4"
     serverless: forbid
     topologies:
       - single
-      - replicaset
-      - sharded
 createEntities:
   - client:
       id: setupClient
@@ -50,7 +48,9 @@ tests:
         arguments:
           client: client
           event:
-            serverDescriptionChangedEvent: {}
+            serverDescriptionChangedEvent:
+              newDescription:
+                type: Standalone
           count: 1
       - name: failPoint
         object: testRunner