{
    "channels": [
        {
            "key":        "tcp_master",
            "type":       "tcp_server",
            "local_ip":   "0.0.0.0",
            "local_port": 2404,
            "bind_app":   "iec",
            "desc":       "IEC-104主站通道 (:2404) — com_router直接投递给libiec"
        },
        {
            "key":         "tcp_ftu",
            "type":        "tcp_client",
            "remote_ip":   "127.0.0.1",
            "remote_port": 54321,
            "desc":        "FTU网口通道 — TCP客户端连接PC上FTU数据转发 (127.0.0.1:54321)"
        }
    ],
    "forward_rules": [
        {
            "listen_ip":     "0.0.0.0",
            "listen_port":   2405,
            "target_channel": "serial_ftu",
            "desc":           "维护软件直连FTU透传"
        }
    ]
}