6 Replies Latest reply: Jun 19, 2013 5:56 AM by DifferentDrummer RSS

    ISP Deliberately Throttling slingbox packets?

    DifferentDrummer

      Dear fellow place shifters,

       

      Does anybody know of any deliberate ISP throttling of sling packets? At my slingbox server location (main house), I have a new slingbox 350, connected to an XBox 360, acting as a Windows Media Center Extender. This location has a nice, Verizon FIOS 35/35 mbit connection.

       

      At my client location (vacation house), about 75 miles away, I have run 3 different clients. The web via a 3ghz Windows 7 PC, an iPad, and a Nexus 7. My vacation house has a nice, Comcast 50+ mbit download speed.

       

      I get fantastic ping and traceroutes between locations. Both locations are running really strong PfSense routers which I built (no VPN between them), and I can achieve a very nice 25-30 mbit/sec download speed when I download big media files from my main house to my vacation house.

       

      However, when I'm running the slingbox client, in any of the three methods above, I can't even reliably hold the horrible "minimum" quality. Constant stutters and restarts. It makes playoff hockey unwatchable!

       

      So, my question is this, has anybody verified that either Comcast or Verizon is doing some packet inspection and specifically throttling Slingbox?

       

      If so, how do you work around? Can we change the port or protocol of the 350?

       

      If not, can anybody offer another way to configure to watch in acceptable quality?

       

      I thought I had all the right ingredients. New Slingbox 350, fat upload speeds of 35mbit/sec on slingbox side. Fast download speeds at client/viewer location. I get great, consistent 36ms ping reply times. I just don't get it!

        • Re: ISP Deliberately Throttling slingbox packets?
          test350 Novice

          IMO it's unlkely that either side is deliberately dropping packets.  If they were, it would be very hard to prove, since intermediate transit links might be to blame.

           

          I have a Slingbox 350 on FiOS in the New York area and get a 4 Mbps+ stream at my vacation home (ping time ~100 ms).  However, I have another viewing location (ping time ~300 ms) where the rate drops to ~300 kbps.  I use some homebrew software to work around that problem.  I have a friend in California with Comcast and he can also get 4 Mbps+ from my Slingbox.

           

          When playing video in the Windows web-based player, hold the Ctrl key and left-click in the video window.  A statistics window will pop up, similar to the one below.  Make sure that Stream Type is TCP.  If not, fix that first.  For example, if at the Slingbox end your pfSense is behind Verizon's Actiontec router, you will need to port forward in both devices.  The default port is 5201, but yours might be different, given your complex network setup.  Is your Comcast modem a dumb bridge, or does it include a router function?  Of course, the pfSense at the viewing location must allow outbound TCP connections to the proper port.

           

          If your TCP streaming is still slow, do a test with Slingbox connected directly to a port on the Actiontec, and a PC connected directly to the Comcast modem (using a software firewall, of course, but be sure that the outbound connection is not blocked, by checking that Stream Type is TCP).

           

          If that doesn't work well, either, connect to a friend's Slingbox or invite a friend to connect to yours, to see at which end the problem lies.

           

           

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            • Re: ISP Deliberately Throttling slingbox packets?
              DifferentDrummer

              Thanks for the tip. You were right, it is set to "RELAY".

               

              Apparently, I hadn't correctly port forwarded traffic to 5201 to my slingbox on my PfSense router. I've done so now remotely, but need to get back to my main house in order to power cycle my slingbox.

              Do you know if one needs to ALSO eneable UpNP? Or is correct port forwarding enough?

              And just to verify, do I only need to recycle the power on the slingbox? Or do I need to run a hard/real RESET procedure on it?

               

              Thanks again!

                • Re: ISP Deliberately Throttling slingbox packets?
                  test350 Novice

                  For TCP streaming to work, two conditions must be met:

                   

                  1. The viewing device must be able to open a TCP connection to the Slingbox, usually on its public IP, port 5201.

                   

                  2. Status of the Slingbox on the Sling Media servers must show that TCP streaming is possible; otherwise the web player won't attempt the connection.

                   

                  It's possible to have (1) but not (2), if the server status has not been updated after a problem with (1) was corrected.  I don't know whether a reboot is necessary (or sufficient) in that case, as I've had the problem correct itself without rebooting.  Perhaps ithe server periodically retests, or changing a setting on the Slingbox prompts a retest.

                   

                  It's also possible to have (2) but not (1), if a firewall or other networking component at the viewing site is blocking the outbound TCP connection.

                   

                  You can test (1), by issuing

                  telnet 111.222.33.44 5201

                  in a command prompt / terminal window.  Of course, use the actual public IP address of the remote Slingbox.

                   

                  If the Slingbox location's pfSense is connected behind the Actiontec, you need to forward the port in both devices, unless pfSense is in the Actiontec's DMZ.  I don't believe that UPnP will "penetrate" to the Actiontec, so you may have to set that up manually.  I personally don't trust UPnP (from a functionality as well as security standpoint) and don't enable it.  See e.g. http://doc.pfsense.org/index.php/What_is_UPNP%3F .

                   

                  To test (2), see my post here: https://community.sling.com/message/90340

                   

                  If (1) and (2) are both ok but you still can't get a TCP stream, run Wireshark on the player machine to see whether the player is attempting a TCP connection, and what responses, if any, it receives.

                    • Re: ISP Deliberately Throttling slingbox packets?
                      DifferentDrummer

                      Again, many thanks for your direction.

                       

                      So I was able to swing home about 2 hours ago and reset my slingbox (repower). I came to work, hoping to find that it would reconfigure itself and allow TCP streaming. However here at work, <Control>-Click on Video Window shows that Stream Type is still "RELAY".

                       

                      BTW: I am not using my Actiontec router. I "cloned" the MAC of the actiontec and I have the FIOS going directly to my PfSense box.

                       

                      I used your trick and was able to see the following:


                      TCP
                      Capability=Supported but Failed
                      Priority=Highest Priority
                      Properties=[]

                      SUDP
                      Capability=Supported and Passed
                      Priority=Lowest Priority
                      Properties=[]

                      SNATT
                      Capability=Supported and Passed
                      Priority=Second Priority
                      Properties=[]

                      Relay
                      Capability=Supported and Passed
                      Priority=Third Priority
                      Properties=[null=4000,dummy=dummy,]

                       

                      So TCP is "Supported but Failed". That "could be" because I had both port forwarding of tcp ports 5201 on my router directed at the slingbox AND had UPnP enabled.

                       

                      I have now disabled UPnP, and still have a properly configured redirecting of tcp port 5201 on the external IP of my PfSense router to my slingbox's internal IP. (confirmed by your Telnet to 5201 tip) However, I am not able to reset my slingbox to try to get it to "recognize" the proper port forwarding and configuing itself. Do you think it will ever re-configure itself? Or do I need to do a hard power cycle again?

                       

                       

                       

                       

                       

                      TCP
                      Capability=Supported but Failed
                      Priority=Highest Priority
                      Properties=[]

                        • Re: ISP Deliberately Throttling slingbox packets?
                          test350 Novice

                          Sorry, I don't know what may be wrong.

                           

                          If your workplace has a sophisticated firewall, it may have a TCP ALG that falsely appears to open the connection.  To confirm that this is not an issue, try telnet to a port where nothing should be listening and verify that you get the expected timeout.

                           

                          Next, you might try running the standalone player and trying to connect.  I believe that it will always try TCP first.  If you get the expected "this device is not supported" message within a couple of seconds (and without it saying "still trying to connect"), then the TCP connection is probably working and the Sling Media servers haven't updated yet.  I don't know how often a 350 "phones home" but you might refresh the sparcs page and see if the "last updated" time changes.  I believe that the timestamp is Pacific time (currently UTC-7).  If you see a time after you fixed the forwarding, without the streaming test passing, then some action is probably needed to provoke a retest.

                           

                          If you still have trouble, there are some other tests we can try.

                          • Re: ISP Deliberately Throttling slingbox packets?
                            DifferentDrummer

                            Some good news. At some point over the last 24 hours, the slingbox re-discovered that it could to tcp streaming (I never was able to get home to cycle the power). So far, the quality is quite improved, averaging an expected streaming mbps speed between 4 and 6 (formerly 1). Proper router port forwarding and slingbox recognition of it is key (UPnP is off).

                             

                            Thank you!