Fundamental ActiveSync networking differences between WM5 and previous WM versions

In my previous article on the secrets of ActiveSync-based Pocket PC networking, I've elaborated on the pre-Windows Mobile 5 Internet pass-through capabilities of ActiveSync.

As has been stated there, the ActiveSync Internet pass-through is in no way a full-fledged Internet connection. In no way can you access a Pocket PC through a simple, plain ActiveSync connection as a TCP/IP device.

With Windows Mobile 5 (WM5 for short) devices, the situation has changed a lot. Now, they're recognized as an entirely different, fully-fledged network card by Windows, as can be seen in this screenshot.

Also, if you, with, say, the great, (for individuals) free networking utility, vxUtil, check the IP it got from ActiveSync of your Pocket PC, you will see that it's no longer 192.168.55.101 (the IP ActiveSync gives to pre-WM5 devices) but a "true" local network IP; in this case, 169.254.2.1. The services of this PDA will, therefore, be fully accessible to your desktop computer (in this screenshot, you can see I can directly ping my WM5 PDA from my desktop computer) and, if you configure your desktop computer to forward ports (please read my previous article on the meaning of this!) to the PDA, to the entire outside world.

This means Windows Mobile 5 devices connected to desktop Windows PC's via ActiveSync are, now, fully accessible by TCP/IP-based applications. You don't need to build a(n additional) Bluetooth PAN or ad-hoc Wi-Fi connection between the two devices any more for the Pocket PC to become accessible.

The importance of this can't be stressed enough: a lot of - with pre-WM5 devices totally impossible - tasks become really easy:

1. you can run applications on your Pocket PC that behave like a server: for example, a lot of peer to peer (non-central server based), TCP/IP-based multiplayer games
2. chatter/VoIP applications like the very good Microsoft Portrait
3. IRC clients with fully usable DCC capabilities (without full, unrestricted Internet access, it's not possible to initiate DCC send/chat requests from the PDA)
4. FTP/Web servers for remote access
5. remote, TCP/IP-based Pocket PC controllers like SOTI's Pocket Controller, PocketVncServ, dotPocket and Microsoft Windows Mobile Developer PowerToys. Now, if your mate/client has a problem with his/her Pocket PC, you will be able to access it distantly without his explicitly logging in to a, say, unrestricted Wi-Fi network. All he'll need to do is doing some port forwarding with either WinGate or the built-in, free Windows Internet Connection Sharing to connect it to the Internet through his desktop computer.
6. Sharing the Internet (say, Wi-Fi) connection present on your PDA with the not directly internet-enabled desktop via my Web proxy server running on the Pocket PC as described here

And, the list continues...

Please note that you will still need to configure port forwarding (which is in detail explained in my previous, networking-related article). But now, at least this is allowed and can be done – unlike with previous Windows Mobile operating systems.

Kudos to Microsoft – this is a really-really welcome addition! With this, ActiveSync-based networking has become far-far easier!

Of course, every bean has its black. The new networking model does have its share of problems. For example, many firewall/viruskiller applications will sense the WM5 PDA as an intruder, unlike with previous Windows Mobile / Pocket PC versions. You will, therefore, may end up having to fine-tune/reconfigure your firewall/viruskiller applications (if you have any) to let your WM5 devices work. Still, I think the advantages the new networking approach has (for example, the much easier Pocket PC control capabilities from distant locations) far outweigh these minor annoyances/one-time configuration needs.

UPDATE (09/15/2006): Old networking model reintroduced in a later WM5 upgrade

If you have a WM5 device that has AKU (please read this article on what AKU's are) 2.2 or later, then, you have the capability of using the "old" networking model if you just deactivate (screenshot here) the, by default, enabled "Enable advanced network functionality" checkbox in the newly added Start / Settings / Connections / USB to PC applet (x51v screenshot here, HTC Wizard here).

The list of WM5 devices already having AKU 2.2(+) includes for example the HTC Wizard, HTC Universal and Dell Axim x51v - these are the WM5 devices I could test in this respect. Note that, as the 2.01 WM5 upgrade for the iPAQ hx4700 is still AKU1.1 only (screenshot of this here), it has no USB to PC applet and, tehrefore, you can't switch back to using the old networking model using this device (a screenshot showing the Connections tab is here; as can be seen, there is indeed no applet there).

In real life, unless you really need the advantages of the WM5 USB networking model outlined in the above article, it's preferable to disable this checkbox. The reasons for this are very simple: as no additional local networks are created when you connect a WM5 device to your PC, 1. there won't be firewall problems 2. the ActiveSync connection will be active (that is, the device becomes visible to the desktop) far earlier than in the other case (again, because no additional network-creating, IP assigning etc. handshake is needed).

As can be seen in thix vxUtil screenshot (compare it to the new model - that is, this one), the IP of the device will be the old, well-known "192.168.55.101". That is, everything I've ever published about the networking model of pre-WM5 devices' USB connections will be topical with AKU2.2+ WM5 devices with disabled WM5-type USB networking.