1 Reply Latest reply: Aug 30, 2010 3:45 PM by eferz RSS

    Need to force SNATT on Mac



      Here is my problem:


      When I connect to the SB from overseas (which is the only reason I got the SB), I get streaming of 20-660kbps which fluctuate wildly and makes it almost unwatchable.


      I reviewed the forums online and did the manual SNATT fix (don't use port forwarding) and it worked great on my Win 7 PC (both Watch on Slingbox.com and Slingplayer).  I get STEADY 1250-1350kbps on SNATT and great picture and sound.


      However, when I try the same thing on the Mac, it can't connect to the Slingbox either on Watch or Slingplayer for Mac.  It seems that the non-port-forwarded set-up kills the Mac connection.  Before I disabled the port-forwarding, the Mac connected  but had the streaming issues described above.  (Coincidentally, I have a second Slingbox at the same sending location which is configured with port forwarding and the Mac can connect and stream from that but will not connect to the non-port-forwarded SB.)


      I need either one of three things:

      1. Get the Mac to connect to the non-port-forwarded SB and get SNATT.

      2. Another way of forcing SNATT on a MAC without disabling port-forwarding.

      3. A way to fix TCP's streaming connection to behave like SNATT, e.g. get the 1200-1300 speed and not fluctuate wildly.


      The set-up is as follows:


      Sending Location:

      Cable Internet (2mbps up and 20 down)

      Router is Apple Airport Extreme

      2 Slingbox Pro HDs on same network


      Receiving Location:

      ADSL Internet (4mbps down)

      Router is Apple Airport Extreme

      Preferred player: Mac Mini (latest with 2.4ghz Core 2 Duo / 2GB Ram, Snow Leopard 10.6.4)


      I also thought about MTU being a potential problem but I can't change MTU on an Airport Express router, so did not try anything there.  Plus sending location has cable internet (not DSL) so I am not sure if MTU can help.


      Any help by you SlingMasters would be most appreciated.



        • Re: Need to force SNATT on Mac
          eferz Expert

          I'm afraid the Mac client isn't able to use SNATT.  I just don't think they implemented it.  As I understand, it works by tunneling UDP packets across a TCP tunnel.  It negotiates connection by the Slingplayer client and the Slingbox server starting a handshake with a centralized server.  Once it has been established then it hands over the communication between the two.  Acting like one of those phonw switch board operaters to see in old movies.


          To improve the connection over the standard TCP stream, you can enable ICMP (ping) on the public interface of the router which hosts the Slingbox.  This will give the Slingplayer another dimension in their algorithm to negotiate better throughput.  Otherwise, you'll have to get a router which can manually adjust the MTU settings.


          Another work around is to use a VPN provider like mentioned in this post, (http://placeshiftingenthusiasts.com/forum/sling-catcher-forums/slingcatcher-cannot-connect/#p850)