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Editorial Team
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Asked: 2026-06-10T05:33:02+00:00

I have read up on the Reachability framework and am still confused why the

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I have read up on the Reachability framework and am still confused why the definition of a host is being reachable is “when a data packet… can leave the local device”.

If reachability returns “yes” then it seems that I still need to try and make a socket connection and until that actually connects I do not really know my host is up. Why doesn’t Reachability use a Ping to get a better idea of whether the host is actually up? And what is the need of this framework in the first place?

My guess is these two, but if anyone knows any other reasons to use the Reachability framework please let me know.

1) Reachability gives a callback which gives instant notification when the internet comes back up. When this occurs a socket connection can be immediately attempted. However in 99% of applications it seems acceptable to just attempt a socket connection every few seconds, or worst case just try to make the connection when a user does a certain action. Granted, this is not an ideal solution but I don’t see why the Reachability framework would ever be really necessary for this reason.

2) Even in the case where a socket connection has been made to the server, Reachability gives an important bit of information about whether the network is G3/WiFi. I think this is the only time Reachability is really necessary because it allows optimization of behavior according to network type.

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1 Answer

  1. Editorial Team

    Reachability is actually quite useful: Given your case (1), you forget that it gives you notifications on both network up and down events. Meaning you can set the callback to handle events such as losing network connectivity (which happens more than you would like on both WiFi and 3G).

    Additionally, testing a connection using a socket is not that straightforward; Socket operations are , by default, blocking, and though you can use asynchronous operations (or threads), doing so involves writing code. Not to mention trying DNS when the network is down, and other such issues. By setting a reachability target using the framework, you can alleviate the need to handle all sorts of issues like these yourself, and simply wait for that callback.

    Hope this helps,

    TG

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