diff --git a/tests/stream_netns/.gitignore b/tests/stream_netns/.gitignore
new file mode 100644
index 00000000..03597c56
--- /dev/null
+++ b/tests/stream_netns/.gitignore
@@ -0,0 +1,3 @@
+/stream_lab_node
+/__pycache__/
+/runs/
diff --git a/tests/stream_netns/topology.py b/tests/stream_netns/topology.py
new file mode 100644
index 00000000..d96a322e
--- /dev/null
+++ b/tests/stream_netns/topology.py
@@ -0,0 +1,97 @@
+"""Описание изолированного стенда; здесь нет сетевых команд и привилегий."""
+
+from dataclasses import asdict, dataclass
+
+
+@dataclass(frozen=True)
+class Country:
+    name: str
+    subnet: str
+    router: str
+    gateway: str
+
+
+@dataclass(frozen=True)
+class Node:
+    number: int
+    country: str
+    ip: str
+    gateway: str
+    nat: str | None
+    client_type: int
+    udp_port: int = 32000
+
+    @property
+    def name(self):
+        return f"n{self.number:02d}"
+
+    @property
+    def mapped_port(self):
+        return 23000 + self.number
+
+
+@dataclass(frozen=True)
+class Nat:
+    name: str
+    country: str
+    ip: str
+    mode: str
+
+
+@dataclass(frozen=True)
+class Wan:
+    a: str
+    b: str
+    ip_a: str
+    ip_b: str
+    rtt_ms: int
+    jitter_ms: float
+    loss_percent: float
+    mbps: int
+
+
+COUNTRIES = (
+    Country("a", "192.0.2.0/24", "ra", "192.0.2.1"),
+    Country("b", "198.51.100.0/24", "rb", "198.51.100.1"),
+    Country("c", "203.0.113.0/24", "rc", "203.0.113.1"),
+)
+NATS = tuple(
+    Nat(f"g_{c.name}{i}", c.name, c.gateway.rsplit(".", 1)[0] + f".{100 + i}", mode)
+    for c in COUNTRIES
+    for i, mode in ((1, "restricted" if c.name == "c" else "cone"), (2, "strict"))
+)
+WANS = (
+    Wan("a", "b", "198.18.0.1", "198.18.0.2", 50, 2, 0.2, 50),
+    Wan("a", "c", "198.18.0.5", "198.18.0.6", 100, 5, 0.5, 30),
+    Wan("b", "c", "198.18.0.9", "198.18.0.10", 150, 10, 1.0, 20),
+)
+
+
+def nodes():
+    result = []
+    number = 1
+    for country, private_count in zip(COUNTRIES, (4, 3, 3)):
+        prefix = country.gateway.rsplit(".", 1)[0]
+        for public in range(2):
+            result.append(Node(number, country.name, f"{prefix}.{11 + public}", country.gateway, None, 0 if not public else 1))
+            number += 1
+        for private in range(private_count):
+            nat = f"g_{country.name}{1 + private // 2}"
+            result.append(Node(number, country.name, f"10.64.1.{2 + private % 2}", "10.64.1.1", nat, 2 if number == 16 else 1))
+            number += 1
+    return tuple(result)
+
+
+NODES = nodes()
+
+
+def wan(a, b):
+    return next(link for link in WANS if {link.a, link.b} == {a, b})
+
+
+def manifest(seed):
+    return {"version": 1, "seed": seed, "countries": [asdict(c) for c in COUNTRIES],
+            "nodes": [dict(asdict(n), name=n.name, mapped_port=n.mapped_port) for n in NODES],
+            "nat": [asdict(n) for n in NATS], "wan": [asdict(w) for w in WANS],
+            "clock": "CLOCK_MONOTONIC, no time namespace", "impairment": "receiver ingress IFB",
+            "private_subnet": "10.64.1.0/24 (reused independently by every NAT)"}