diff --git a/.env.example b/.env.example
index 0a7b75e..41ee727 100644
--- a/.env.example
+++ b/.env.example
@@ -32,8 +32,10 @@ NETX_UME_TOPO_NODES_PATH=/restconf/data/zte-resources-module:TopoNodes
 NETX_UME_TOPOLOGICAL_LINKS_PATH=/restconf/data/zte-resources-module:TopologicalLinks
 NETX_UME_SYNC_TOPOLOGY_AUTO_ENABLED=true
 NETX_UME_SYNC_TOPOLOGY_EVERY_HOURS=24
-# NETX_UME_TOPOLOGY_TIMEOUT_S=600
-# NETX_UME_SYNC_TOPOLOGY_STALE_RUNNING_SEC=1800
+# Topology dump: 0 = no read timeout (wait while TCP stays up). Set e.g. 3600 to cap.
+# NETX_UME_TOPOLOGY_TIMEOUT_S=0
+# Reap stuck topology jobs only after this many seconds (default 24h).
+# NETX_UME_SYNC_TOPOLOGY_STALE_RUNNING_SEC=86400
 NETX_UME_SYNC_ALARMS_CURRENT_ENABLED=true
 NETX_UME_SYNC_ALARMS_CURRENT_INTERVAL_S=18000
 NETX_UME_SYNC_ALARMS_CURRENT_SKIP_WHEN_WS=true
diff --git a/netx_api/config.py b/netx_api/config.py
index d814a50..83c95b6 100644
--- a/netx_api/config.py
+++ b/netx_api/config.py
@@ -58,8 +58,10 @@ class Settings(BaseSettings):
     ume_sync_inventory_every_hours: int = 48
     ume_sync_topology_auto_enabled: bool = True
     ume_sync_topology_every_hours: int = 24
-    ume_topology_timeout_s: float = 600.0
-    ume_sync_topology_stale_running_sec: int = 1800
+    # Topology REST dump: 0 = no read timeout (wait while the connection stays up).
+    ume_topology_timeout_s: float = 0.0
+    # Do not reap a still-running topology pull until this age (long UME dumps).
+    ume_sync_topology_stale_running_sec: int = 86400
     ume_token_path: str = "/restconf/operations/zte-security:oauth_token"
     ume_token_handshake_path: str = "/restconf/operations/zte-security:oauth_handshake"
     ume_token_logout_path: str = "/restconf/operations/zte-security:oauth_token"
diff --git a/netx_api/ume_client.py b/netx_api/ume_client.py
index 799fc4c..36bc7cb 100644
--- a/netx_api/ume_client.py
+++ b/netx_api/ume_client.py
@@ -237,16 +237,30 @@ class UMEClient:
                 headers[self.auth_header] = token
         return headers
 
-    def _client(self, *, timeout_s: float | None = None) -> httpx.Client:
+    def _client(
+        self,
+        *,
+        timeout_s: float | None = None,
+        timeout: httpx.Timeout | None = None,
+    ) -> httpx.Client:
         # Use explicit HTTPTransport to keep behavior consistent with onsite validation.
         # In this mode, requests run over HTTP/1.1 and avoid HTTP/2 negotiation issues.
         transport = httpx.HTTPTransport(verify=self.verify_tls, http2=False)
-        if timeout_s is None:
-            to: float | httpx.Timeout = self.timeout_s
+        if timeout is not None:
+            to: float | httpx.Timeout = timeout
+        elif timeout_s is None:
+            to = self.timeout_s
+        elif float(timeout_s) <= 0:
+            # No read/write deadline — keep waiting while the peer still streams.
+            to = httpx.Timeout(connect=30.0, read=None, write=None, pool=30.0)
         else:
-            # Large topology dumps need a long read window; connect stays short.
             read_s = max(3.0, float(timeout_s))
-            to = httpx.Timeout(connect=min(30.0, read_s), read=read_s, write=min(60.0, read_s), pool=30.0)
+            to = httpx.Timeout(
+                connect=min(30.0, read_s),
+                read=read_s,
+                write=min(60.0, read_s),
+                pool=30.0,
+            )
         return httpx.Client(transport=transport, timeout=to)
         
 
@@ -618,10 +632,11 @@ class UMEClient:
         return rows, diag
 
     def _topology_timeout_s(self) -> float:
+        """Read timeout seconds for topology dumps; ``0`` = wait while connected."""
         base = float(getattr(settings, "ume_topology_timeout_s", 0) or 0)
-        if base > 0:
-            return max(30.0, base)
-        return max(self.timeout_s, 600.0)
+        if base <= 0:
+            return 0.0
+        return max(30.0, base)
 
     @staticmethod
     def _extract_restconf_list(payload: dict[str, Any], *, containers: list[str], items: list[str]) -> list[dict[str, Any]]:
diff --git a/netx_api/ume_sync_topology.py b/netx_api/ume_sync_topology.py
index 9fa57db..ae62f6a 100644
--- a/netx_api/ume_sync_topology.py
+++ b/netx_api/ume_sync_topology.py
@@ -109,7 +109,7 @@ def _ume_ne_id_for_topo_node(*, node_type: str, name: str) -> str:
 
 
 def _stale_running_sec() -> int:
-    return max(300, int(getattr(settings, "ume_sync_topology_stale_running_sec", 1800) or 1800))
+    return max(3600, int(getattr(settings, "ume_sync_topology_stale_running_sec", 86400) or 86400))
 
 
 def fail_stale_topology_running_jobs(db: Session | None = None) -> int: