DLink DCS-935L Flaky Connection (SS Specific?)
  • I have a DCS-935L, which isn't in an important role. In the Dlink direct connection (their web GUI hanging on the IP address) and in the DLink iOS app the connection is rock solid stable. My router reports that the cam - which is wifi only - has full signal.

    To import the cam data into SS, I'm using H.264 RTSP and a DLink profile which includes the DCS-936L. Works OK for a few seconds then the connection drops for 6 or 7 seconds, with "communication error" in the window. When I manually specify the connection using IP, the RTSP port and the play1.sdp stream, exactly the same thing happens. I get the same drops whether I use TCP or UDP. None of my other cams act in this way.

    I feel like this is an SS issue due to the cam being accessible from other interfaces, but I can't find any way of bug fixing the connection to a single camera, or any other options I can tweak. The cam is on the newest firmware and I'm using SS 4.1b2. Any ideas?
  • I get this error:

    23/01/2017 19:33:23: Error communicating with the network device "Kitchen Side (IP 5)". 4.1b2,10,835 Excessive packet loss from network device, the network may be too slow or defective, or this computer may be overloaded. Check the network and/or reduce this camera's frame rate.

    Cam is set to 512Kbps H.264 at 720P, 10fps. I've jumped onto a non-standard RTSP port. This setup is way less demanding than some of my other cams. Computer not even slightly overloaded, memory pressure reports as 20% or so. Same deal when I write a manual connection to the cam.
  • Another update. When I load the RTSP stream directly in VLC it's rock-solid.
  • 18mins streaming in VLC at 10fps and it's at 17000 frames decoded with 2 lost at about 2300kb/s. Format is H264 - MPEG-4 - AVC (Part 10) (h264). Works like this with current and last-good legacy firmware. Stream is at rtsp://username:password@IP.IP.IP.IP:PORT/play1.sdp

    I may have to change the cam if it's randomly offline in SSpy every few seconds. Bearing in mind the VLC test, it's pretty clear that there's something going on in the app, but I have no idea how to further bugfix.
  • I cannot get DCS-935L to maintain a solid connection under any config inside SecuritySpy - including General RTSP modes and all D-Link Profiles.

    Streams perfectly stable to any other app including VLC as mentioned above.

    Anybody have a solution/bugfix for this? It is clearly a problem isolated to SecuritySpy.
  • Could both of you please confirm that this problem happens in the latest version of SecuritySpy (currently 4.1.1)?

    If you open the Camera Info window and enable the "Packet Loss" column, what is shown for the packet loss for the camera? To enable this column, click the header (where you see the column names) and you will get a menu that allows you to enable/disable columns.

    If either of you are using the camera wirelessly, could you please try it connected by wired Ethernet as a test, to see if there is any difference in reliability.

    If you are getting a "communication error" then there should be further information written to the log file. You can get this via the "Open Log" option from the File menu in SecuritySpy. Please save this to your desktop and attach it to an email to support@bensoftware.com and we will take a look.
  • Hi,

    - I can confirm that I am running the latest version of SecuritySpy 4.1.1.

    - The packet loss is 0.0%.

    - The D-Link DCS-935L is wireless only (there is no ethernet connectivity option). I am running on a very clean an uncongested 5Ghz/11n channel at a short distance of 3-4 metres line of site from the wireless router.

    - I can achieve a solid RTSP stream with zero dropouts for this camera via many other apps including VLC (Mac, tvOS and iOS), UnionCamManager (Mac), LiveCams Pro (iOS), CamTV (tvOS and iOS).

    - I just emailed you the log.txt file as requested.

    Thanks in advance.
  • Any news on this Ben? I have two dcs-935L cameras here which I'd like to try with SS. I am using the latest trial download and get the exact symptoms described above which makes SS unworkable
  • Could you please try this, under Preferences -> Cameras -> Device for the camera in question:

    - Set the Profile to Manual Configuration
    - Enter play1.sdp as the Request
    - For the Format first try RTSP TCP, click the Apply Preferences button, and test for a while
    - Then set the Format to RTSP UDP, click the Apply Preferences button, and test that for a while

    Is there a difference in reliability between the TCP option and the UDP option?
  • Ben,

    Thanks for the speedy reply. Success!

    RTSP UDP does the trick.

  • Good to hear that. Some cameras simply work better when streaming UDP (even though TCP is a more reliable transport protocol).

    Could you please let me know which of the existing D-Link profiles allows pan/tilt control for this camera? Once I have this info I can create a special profile for the DCS-935L that uses UDP transport and allows pan/tilt control.
  • The DCS-935L doesn't have pan/tilt
  • You are right! My mistake. OK I'll go ahead and make a special profile for it that uses UDP, without pan/tilt.
  • Thanks again. I'm new to NVR so learning lots.
  • Hi - this seems to be working for me now as well (despite trying UDP and manually specifying the RTSP stream before)! Thanks a lot Ben.

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