fix: remap REPEAT DMRD slot to peer OPTIONS for cross-slot downlink

Flip the DMRD timeslot bit per receiver so hotspots hear group voice on
the TS where the TG is configured (static OPTIONS or dynamic UA), and
emit inject-proxy BRDG field 7 on that same slot for monitor TE parity.

src/adn_server/application/report/monitor_topology.py

@@ -31,7 +31,7 @@ from __future__ import annotations
 import copy
 from typing import Any
 
-from adn_server.application.routing.helpers import is_special_tg, peer_should_receive_group_voice
+from adn_server.application.routing.helpers import is_special_tg, peer_downlink_voice_slot, peer_should_receive_group_voice
 from adn_server.application.proxy.deployment import is_proxy_inject_only, proxy_target_system
 from adn_server.domain.value_objects import bytes_4, int_id
 
@@ -262,6 +262,26 @@ def _echo_tx_target_peer(parts: list[str], peers: dict[Any, Any]) -> bytes | Non
     return _peer_key_from_voice_csv(parts, peers)
 
 
+def _voice_event_with_peer_display_slot(
+    parts: list[str],
+    *,
+    peer: dict[str, Any],
+    peer_key: bytes,
+    wire_slot: int,
+    tgid: int,
+    sys_cfg: dict[str, Any] | None,
+) -> list[str]:
+    """Set BRDG CSV field 7 to the receiver's configured listen TS (monitor TE chip)."""
+    out = list(parts)
+    if len(out) > 7:
+        out[7] = str(
+            peer_downlink_voice_slot(
+                peer, wire_slot, tgid, sys_cfg, peer_id=peer_key,
+            )
+        )
+    return out
+
+
 def _remap_voice_event_to_slot(
     parts: list[str],
     *,
@@ -361,13 +381,21 @@ def remap_inject_proxy_voice_events(
         if not receivers:
             return [event]
         remapped: list[str] = []
-        for peer_key, _peer in receivers:
+        for peer_key, peer in receivers:
             mapped_slot = slot_map.get(peer_key)
             if mapped_slot is None:
                 continue
+            peer_parts = _voice_event_with_peer_display_slot(
+                parts,
+                peer=peer,
+                peer_key=_peer_key_from_int(peer_key),
+                wire_slot=voice_slot,
+                tgid=tgid,
+                sys_cfg=sys_cfg,
+            )
             remapped.append(
                 _remap_voice_event_to_slot(
-                    parts, target=target, slot=mapped_slot, peer_key=peer_key
+                    peer_parts, target=target, slot=mapped_slot, peer_key=peer_key
                 )
             )
         return remapped if remapped else [event]
@@ -390,7 +418,7 @@ def remap_inject_proxy_voice_events(
         tx_parts = list(parts)
         tx_parts[2] = "TX"
         tx_parts[5] = str(int_id(peer_key))
-        for other_key, _peer in _peers_receiving_tgid(
+        for other_key, peer in _peers_receiving_tgid(
             connected,
             slot=voice_slot,
             tgid=tgid,
@@ -402,9 +430,17 @@ def remap_inject_proxy_voice_events(
             other_slot = slot_map.get(other_key)
             if other_slot is None:
                 continue
+            peer_parts = _voice_event_with_peer_display_slot(
+                tx_parts,
+                peer=peer,
+                peer_key=_peer_key_from_int(other_key),
+                wire_slot=voice_slot,
+                tgid=tgid,
+                sys_cfg=sys_cfg,
+            )
             results.append(
                 _remap_voice_event_to_slot(
-                    tx_parts,
+                    peer_parts,
                     target=target,
                     slot=other_slot,
                     peer_key=other_key,

src/adn_server/application/routing/helpers.py

@@ -638,6 +638,64 @@ def synthetic_group_dmrd_route_packet(slot: int, tgid: int) -> bytes:
     return b"DMRD" + b"\x00" * 4 + bytes_3(tgid) + b"\x00" * 4 + bytes([bits]) + b"\x00" * 38
 
 
+def peer_downlink_voice_slot(
+    peer: dict[str, Any],
+    wire_slot: int,
+    tgid: int,
+    sys_cfg: dict[str, Any] | None = None,
+    *,
+    peer_id: bytes | None = None,
+) -> int:
+    """Monitor/BRDG field 7: TS where this peer listens for ``tgid`` (OPTIONS or UA)."""
+    static = peer_options_static_tg_slot(peer, tgid)
+    if static is not None:
+        return static
+    if sys_cfg is not None and peer_id is not None:
+        tgid_i = int(tgid)
+        pk = bytes_4(int_id(peer_id))
+        for voice_slot in (1, 2):
+            locked = peer_single_exclusive_tgid(
+                peer, voice_slot, sys_cfg, peer_id=peer_id,
+            )
+            if locked is not None and int(locked) == tgid_i:
+                return voice_slot
+        store = sys_cfg.get("_PEER_UA_MULTI_TGS")
+        if isinstance(store, dict):
+            per_peer = store.get(pk)
+            if isinstance(per_peer, dict):
+                for voice_slot in (1, 2):
+                    slot_set = per_peer.get(voice_slot)
+                    if isinstance(slot_set, set) and tgid_i in slot_set:
+                        return voice_slot
+    return int(wire_slot)
+
+
+def remap_dmrd_to_peer_static_slot(
+    packet: bytes,
+    peer: dict[str, Any],
+    sys_cfg: dict[str, Any] | None = None,
+    *,
+    peer_id: bytes | None = None,
+) -> bytes:
+    """Flip DMRD slot bit so the hotspot RF TS matches OPTIONS/UA for this TG."""
+    parsed = parse_dmrd_route_fields(packet)
+    if parsed is None:
+        return packet
+    voice_slot, tgid, call_type = parsed
+    if call_type not in ("group", "vcsbk"):
+        return packet
+    if is_special_tg(str(tgid)):
+        return packet
+    cfg_slot = peer_downlink_voice_slot(
+        peer, voice_slot, tgid, sys_cfg, peer_id=peer_id,
+    )
+    if cfg_slot == voice_slot:
+        return packet
+    bits = packet[15]
+    new_bits = bits ^ (1 << 7)
+    return packet[:15] + bytes([new_bits]) + packet[16:]
+
+
 def repeat_downlink_report_slot(
     wire_slot: int,
     tgid: int,
@@ -656,27 +714,11 @@ def repeat_downlink_report_slot(
         peer = peers.get(peer_id)
         if not isinstance(peer, dict):
             continue
-        static_slot = peer_options_static_tg_slot(peer, tgid_i)
-        if static_slot is not None:
-            display_slots.add(static_slot)
-            continue
-        if not sys_cfg:
-            continue
-        pk = bytes_4(int_id(peer_id))
-        for voice_slot in (1, 2):
-            locked = peer_single_exclusive_tgid(
-                peer, voice_slot, sys_cfg, peer_id=peer_id,
+        display_slots.add(
+            peer_downlink_voice_slot(
+                peer, wire_slot, tgid_i, sys_cfg, peer_id=peer_id,
             )
-            if locked is not None and int(locked) == tgid_i:
-                display_slots.add(voice_slot)
-        store = sys_cfg.get("_PEER_UA_MULTI_TGS")
-        if isinstance(store, dict):
-            per_peer = store.get(pk)
-            if isinstance(per_peer, dict):
-                for voice_slot in (1, 2):
-                    slot_set = per_peer.get(voice_slot)
-                    if isinstance(slot_set, set) and tgid_i in slot_set:
-                        display_slots.add(voice_slot)
+        )
     if len(display_slots) == 1:
         return display_slots.pop()
     return int(wire_slot)

src/adn_server/infrastructure/twisted_adapters/udp_hbp.py

@@ -50,6 +50,7 @@ from ...application.routing.helpers import (
     peer_should_receive_group_voice,
     peer_single_exclusive_tgid,
     register_peer_ua_session,
+    remap_dmrd_to_peer_static_slot,
     resolve_voice_peer_id,
     repeat_downlink_report_slot,
     seed_peer_ua_session_from_status,
@@ -576,6 +577,11 @@ class HBPProtocol(DatagramProtocol):
         if _packet[:4] == DMRD:
             if not self._peer_should_receive_dmrd(_peer, _packet):
                 return
+            peer = self._peers.get(_peer)
+            if peer is not None:
+                _packet = remap_dmrd_to_peer_static_slot(
+                    _packet, peer, self._config, peer_id=_peer,
+                )
             _packet = b"".join([_packet[:11], _peer, _packet[15:]])
         self.transport.write(_packet, self._peers[_peer]["SOCKADDR"])
 

tests/application/test_monitor_topology.py

@@ -228,6 +228,27 @@ def test_local_hotspot_rx_fans_out_tx_only_to_peers_with_matching_tg() -> None:
     assert "SYSTEM-4" not in by_system
 
 
+def test_local_hotspot_rx_companion_tx_uses_receiver_options_slot() -> None:
+    """HS2 TX slot 2 / TG 7144 → HS1 with TS1=7144 gets BRDG field 7 = 1 (monitor TE)."""
+    hs1 = bytes_4(730001)
+    hs2 = bytes_4(730002)
+    peers = {
+        hs1: _peer(options=b"TS1=7144;TS2=714,71442;"),
+        hs2: _peer(options=b"TS2=7144;"),
+    }
+    config = _proxy_config(peers)
+    peer_slots = {hs1: 0, hs2: 1}
+    raw = "GROUP VOICE,START,RX,SYSTEM,3262598598,730002,730002,2,7144"
+    events = remap_inject_proxy_voice_events(
+        raw, config, config["SYSTEMS"], peer_slots
+    )
+    tx_events = [e for e in events if e.split(",")[2] == "TX"]
+    assert len(tx_events) == 1
+    parts = tx_events[0].split(",")
+    assert parts[3] == "SYSTEM-0"
+    assert int(parts[7]) == 1
+
+
 def test_obp_tx_single_hotspot_remaps_dynamic_tg_not_in_static() -> None:
     """One HS online: downlink/monitor must remap TX even when TG is UA-only (not in OPTIONS)."""
     peer = bytes_4(730039101)

tests/application/test_peer_single_downlink.py

@@ -30,14 +30,17 @@ from adn_server.application.routing.helpers import (
     tg4000_reset_on_vhead,
     clear_peer_rx_status_slots,
     peer_options_static_tg_slot,
+    peer_downlink_voice_slot,
     peer_receives_group_tgid,
     peer_should_receive_group_voice,
+    remap_dmrd_to_peer_static_slot,
     peer_single_blocks_group_voice,
     peer_single_blocks_uplink,
     peer_single_exclusive_tgid,
     register_peer_ua_multi_tg,
     register_peer_ua_session,
     repeat_downlink_report_slot,
+    peer_downlink_voice_slot,
     seed_peer_ua_session_from_status,
 )
 
@@ -79,12 +82,46 @@ def test_dynamic_tg_on_opposite_slot_receives_group_voice() -> None:
 
 def test_repeat_downlink_report_slot_cross_slot_static() -> None:
     peers = {
-        _peer_id(): {"OPTIONS": b"TS2=730444;"},
+        _peer_id(): {"OPTIONS": b"TS1=7144;"},
     }
     slot = repeat_downlink_report_slot(
-        1, 730444, peers, (_peer_id(),), _sys_cfg(),
+        2, 7144, peers, (_peer_id(),), _sys_cfg(),
     )
-    assert slot == 2
+    assert slot == 1
+
+
+def test_peer_downlink_voice_slot_cross_slot_static() -> None:
+    peer = {"OPTIONS": b"TS1=7144;TS2=714,71442;"}
+    assert peer_downlink_voice_slot(peer, 2, 7144) == 1
+    peer2 = {"OPTIONS": b"TS2=7144;"}
+    assert peer_downlink_voice_slot(peer2, 1, 7144) == 2
+
+
+def test_remap_dmrd_flips_slot_to_options_static_ts() -> None:
+    from tests.harness.deterministic import DeterministicScenario, PacketSpec
+
+    peer = {"OPTIONS": b"TS1=7144;TS2=714,71442;"}
+    burst = DeterministicScenario.voice_burst_spec(
+        PacketSpec(dst_id=7144, slot=2, peer_id=730044402, rf_src=7300444),
+        seq=1,
+        dtype_vseq=1,
+    ).data()
+    assert burst[15] & 0x80
+    remapped = remap_dmrd_to_peer_static_slot(burst, peer)
+    assert not (remapped[15] & 0x80)
+
+
+def test_remap_dmrd_keeps_slot_when_options_match_voice_ts() -> None:
+    from tests.harness.deterministic import DeterministicScenario, PacketSpec
+
+    peer = {"OPTIONS": b"TS2=7144;"}
+    burst = DeterministicScenario.voice_burst_spec(
+        PacketSpec(dst_id=7144, slot=2, peer_id=730044402, rf_src=7300444),
+        seq=1,
+        dtype_vseq=1,
+    ).data()
+    remapped = remap_dmrd_to_peer_static_slot(burst, peer)
+    assert remapped[15] == burst[15]
 
 
 def test_repeat_downlink_report_slot_dynamic_on_ts2() -> None:

tests/infrastructure/test_hbp_repeat_options_filter.py

@@ -72,6 +72,34 @@ def test_repeat_only_reaches_peers_with_matching_options() -> None:
     assert other_pkts == []
 
 
+def test_repeat_remaps_slot_to_peer_options_ts() -> None:
+    """Simplex TS2 TX / TG 7144 → duplex TS1=7144 receives DMRD on TS1 (slot bit flip)."""
+    stack = build_hbp_repeat_stack(talker_alias=False, system_name="MASTER-A")
+    stack.config["PROXY"] = {"TARGET_SYSTEM": "MASTER-A"}
+    stack.hbp._CONFIG = stack.config
+    simplex = bytes_4(730002)
+    duplex = bytes_4(730001)
+    addr_simplex = ("10.0.0.31", 62031)
+    addr_duplex = ("10.0.0.30", 62030)
+    stack.register_peer(simplex, addr_simplex, options="TS2=7144;")
+    stack.register_peer(duplex, addr_duplex, options="TS1=7144;TS2=714,71442;")
+
+    spec = PacketSpec(
+        peer_id=int.from_bytes(simplex, "big"),
+        rf_src=730002,
+        dst_id=7144,
+        slot=2,
+        stream_id=0x22334455,
+        payload=b"\x00" * 33,
+    )
+    burst = DeterministicScenario.voice_burst_spec(spec, seq=1, dtype_vseq=1).data()
+    stack.inject(burst, addr_simplex)
+
+    duplex_pkts = [p for p in stack.transport.for_addr(addr_duplex) if p[:4] == DMRD]
+    assert len(duplex_pkts) == 1
+    assert not (duplex_pkts[0][15] & 0x80)
+
+
 def test_repeat_cross_slot_static_tg_downlink() -> None:
     """Voice on TS1 reaches hotspot that lists the TG only on TS2 (PR #2 parity)."""
     stack = build_hbp_repeat_stack(talker_alias=False, system_name="MASTER-A")