TCP Connection Problems on Apple iOS 10


Since Apple’s release of iOS 10 for iPhones and iPads, we have been getting a number of calls and emails saying that various navigational Apps that read wireless NMEA data from our products have stopped working, including our free iAIS app.

There are two modes/protocols that our wireless NMEA products can work in; TCP which is a reliable one to one type connection supported by most apps and UDP which is a broadcast protocol that allows multiple devices to all receive the same data.

When we started to investigate, we found that TCP communication on all Apps no longer worked with iOS 10 and UDP only worked on some apps. At first we thought this might have been an Apple API type change that had caused the problem, but then we discovered that changing the IP address of our wireless NMEA products from to fixed the problem.

The IP address range is usually reserved for Ad-Hoc networks where there is no DHCP server and dates back to our first iAIS product (released in 2011) that only supported Ad-Hoc networks. With the release of Android, which did not support Ad-Hoc networks, we updated our wireless NMEA products to the more common Access Point mode but retained the IP address, to avoid changing too many Apps and Documentation.

Now it seems that Apple are clamping down on TCP connections on Ad-Hoc networks and this means that all customers who have updated their iPhone or iPad to iOS 10, will need to change the IP address of their wireless NMEA product, if they have one of our; iAIS, WLN10, WLN10HS, WLN20, NavLink, PilotLink or AIT3000 units. Please note that our iNavHub and Sonar Server products are not affected by the iOS change.

To make this procedure as easy and simple as possible, we have created a new Tech Note that explains what needs to be done. Click here to download.


13 thoughts on “TCP Connection Problems on Apple iOS 10

    • Hi Jason,

      First let us see if the wireless NMEA device you have is using the older address or the newer address. Go to Settings>Wi-Fi on your iPhone, connect to our wireless device and then after the “Tick” appears to the left of the wireless network name, click on the “i” Info icon to the right of the wireless network name. This takes you to the network properties page and you will see the IP address that your iPhone has been given.

      If it is, then you have nothing to worry about and everything shoud be fine. If it is then you need to follow the instructions on the Tech Note that we give you the download link to in this article.

      Best regards

      • Hi Paul
        I am following the steps as per the tech note to change the IP address using the Terra Term program but when get the page which should give me the “hello” prompt it starts with hello and then continues steaming other data to the effect that I can not put in the $ signs to continue.I am using an Ipad air with IOS 10

      • Hi Arthur,

        When you have AIS/GPS data coming in to the wireless interface you will see it streaming down the screen in TeraTerm, BUT it is possible to still type the three dollar signs $$$ and press the Enter key. Alteratively, you can copy the three dollar signs from a text editor, email, etc. and paste them in to TeraTerm using the Paste option under the Edit menu of Tera Term.

        Best regards

      • Paul, I just used my Mac to make the change. The folks answering the phone said it could not be done. I was going to send you the procedure, but if you already have it (basically the same steps, but using, then I will not bother sending what I did.

      • Hi John,
        Well done for proving the sales team wrong, they always “err on the side of caution” which is probably a good thing really.
        Glad you got everything sorted and if you have anymore questions, please just let me know.
        Best regards

  1. (AIS3000) Made the update for iOS 10 and wifi is now working fine, unit is receiving info from other boats and sharing to plotter via NMEA2k just fine, but it’s not sending our information out. Any suggestions?

    • Hi Martin,
      Glad you got iOS 10 sorted and your AIT3000 is sending AIS data to your plotter. As long as the Green Power LED is constantly ON, then this indicates that the AIT3000 is passing all of its internal tests and is happy with Power, GPS and the VHF aerial which it does a VSWR test on, every time it transmits.
      I would have a read of this article I wrote which might give you some confidence that your AIT3000 is transmitting, but if you have any more questions after reading this, please let me know.
      Best regards

      • Green power is solid. Green wi-if light is flashing. Anything I can do to fix this without a laptop?

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