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+# NVR HiWatch DS-N316(D) Fix Progress
+
+## Problem
+All 13 XM cameras (53H20AF) cycle online/offline every ~30 seconds on NVR.
+NVR IP: 192.168.1.123, FW: V4.76.015 build 250210
+Network: 192.168.1.x (Знаменское, через Cudy router 100.70.54.204 Netbird)
+
+## Camera List
+1:192.168.1.42, 2:192.168.1.69, 3:192.168.1.101, 4:192.168.1.40, 5:192.168.1.64
+6:192.168.1.70, 7:192.168.1.20, 8:192.168.1.58, 9:192.168.1.57, 10:192.168.1.56
+11:192.168.1.63, 12:192.168.1.47, 13:192.168.1.41
+
+## Key Discovery: DVR-IP Protocol Works!
+- XM camera admin password: empty (""), XM hash: tlJwpbo6
+- Login: EncryptType=MD5, PassWord=tlJwpbo6, UserName=admin, port 34567
+- msg_id 1000=login, 1042=config_get, 1040=config_set
+- TCPMaxConn: 10 (connection limit theory WRONG)
+- RTSP accepts ANY auth (Basic, no auth, wrong creds) — auth NOT the issue
+
+## What Was Tried & Failed
+- Disabling sub-stream (VideoEnable=false) → NVR still tries stream 102, gets accessFroDeviceStreamFailure
+- Anonymous RTSP (Anonymity=true) → still cycles
+- HIKVISION protocol → online=true but no video (can't get device params)
+- Custom Protocol → badXmlContent (400)
+- streamType=main → NVR returns 400 (only "auto" supported)
+- PUT /ISAPI/Streaming/channels → notSupport
+- ONVIF DeleteProfile → camera ignores
+- SetVideoEncoderConfiguration → camera closes connection
+- Different passwords → no effect
+- MTU change → no effect
+
+## Current NVR State
+- CH1 still has 192.168.1.42 configured (camera is FROZEN — ports closed, pings OK, needs power cycle)
+- All other 12 cameras are alive
+
+## Root Cause Investigation
+- NVR error: accessFroDeviceStreamFailure (stream access fails)
+- RTSP DESCRIBE works fine from client (200 OK)
+- Camera accepts any RTSP auth
+- Issue may be in SETUP/PLAY phase or RTP transport
+- NVR does ONVIF → gets RTSP URL → tries DESCRIBE/SETUP/PLAY → fails after ~20-30s
+
+## SSH Tunnels Pattern
+```bash
+ssh -o StrictHostKeyChecking=no -o ConnectTimeout=10 -o ServerAliveInterval=10 -L LOCAL:REMOTE_IP:REMOTE_PORT root@100.70.54.204 -N -f
+```
+
+## Key Scripts
+- /root/nvr_clean_test.py — full test: DVR-IP config + NVR add + monitor
+- /root/xm_full_explore.py — explore camera settings via DVR-IP
+- /root/xm_disable_substream.py — disable/enable sub-stream
+- /root/xm_fix_rtsp.py — change RTSP anonymity settings
+
+## Next Steps
+1. Do full RTSP session (SETUP+PLAY) to verify stream actually works
+2. Check if NVR uses TCP or UDP for RTP transport
+3. Maybe try adding camera with empty password ("12345678" - 8 char minimum for NVR)
+4. Consider: maybe NVR ONVIF GetStreamUri returns different URL than direct ONVIF query
+5. Camera 192.168.1.42 needs physical power cycle