New dial-up networking model of WM5 AKU3 - a must if you use your WM phones as modems

Now that there already are some AKU3 devices (mostly MS Smartphones) on the market (for example, the HTC Dash (see for example this excellent Smartphone Thoughts review), and I, as I know quite much about Bluetooth, network sharing (I’m the author of the one and only POST-capable, free HTTP network sharing proxy for the Pocket PC) and connectivity issues of Windows Mobile devices, have been receiving a LOT of related questions (see for example this), I have decided to update my well-known Use your Pocket PC Phone Edition as a modem for your other Pocket PC's” tutorial so that it contains AKU3-related information and to also explain why dial-up connections in the latest, AKU3 version of WM5 behave completely different from earlier operating system versions.

This article will be of extreme interest to anyone using their Microsoft-based phones (let them be either full Pocket PC’s or “just” MS Smartphones) as cellular (GPRS / EDGE / UMTS / HSDPA etc.) modems because it explains everything about this subject, including the changes over the old model.

1. The most important changes, connectivity-wise

There are major changes in the connectivity model of AKU3 when it comes to serving clients that would like to use a Windows Mobile phone as a modem via either Bluetooth or infrared. In the following two subsections, I elaborate on both connection forms.

1.1 Bluetooth: No BT DUN profile any more

In AKU 3+, the Bluetooth DUN (Dial-up Networking) profile is no longer supported at all, only the PAN (Personal Area Network). Now, it’s via BT PAN’s that cellular-only network connections are shared and you have no access to DUN functionality any more.

This means clients discovering AKU3-based Windows Mobile phones will NOT see as modems, unlike with operating system versions prior to AKU3. This means that instead of seeing this (Microsoft BT stack) and this (Widcomm BT stack), you will see this (with the MS BT stack as clients) and this , this and this (three Widcomm-based clients (iPAQ 2210, hx4700 and the Pocket Loox 720)).

The latter screenshots, in essence, show you won’t be able to use Windows Mobile phones with Microsoft BT stack-based clients as the latter have no BT PAN support at all – along with a lot of other types of devices. That is, not so many “client” operating systems (“client” refers to devices that would like to use Windows Mobile phones to access the Net) support the (quite advanced) BT PAN profile as the “traditional” BT DUN dial-up method.

In the following subsections, I elaborate on the PAN compatibility issues both desktop and handheld OS’es. After that, I elaborate on other, related issues like port forwarding and convenience issues.

1.1.1 Desktop OS’es and BT PAN compatibility

On Microsoft Windows desktop PC’s, there is no difference: even the MS BT stack supports joining already-existing BT PAN networks as has been explained, say, here.

On Linux and Mac OS, however, the situation is vastly different: in some cases, only DUN is implemented in some Linux distributions; so is the case with the different Mac OS versions as far as I know as is also pointed out here.

1.1.2. Handheld OS’es and BT PAN compatibility

As far as Pocket PC’s are concerned, the situation here is far worse than that of the desktop Windows case. Here, it’s only the Widcomm/Broadcom BT stack that has always supported BT PAN. The Pocket PC-based Microsoft BT stack doesn’t have any kind of BT PAN client support as can also be seen in this screenshot. This shows PPC MS BT stack clients don’t see any profiles that would make it possible to access the net via AKU3 Phone Edition (or MS Smartphone) devices. Opposed to this is the pre-AKU3 case where DUN was still visible as can be seen in this screenshot (from the already-linked pre-AKU3 article “Use your Pocket PC Phone Edition as a modem for your other Pocket PC's! - a full tutorial”)).

Non-common Bluetooth stacks (like the ones that come with old BT cards – for example, see the original drivers that come with the Belkin F8T020 card – see this for more info) don’t support PAN either (they only support DUN).

Other (non-Windows Mobile) clients that can only use the DUN profile include Palm OS devices (the Palm OS’ BT PAN capabilities are really bad – Lan Access is, theoretically, supported via BT, but not in practice), some (not all! For example, the Sharp Zaurus has BT PAN support) Linux devices (for example, the Nokia 770), some mobile devices with proprietary operating systems (for example, some Garmin GPS units/computers) etc.

1.2. What do you need to know about infrared support?

It, unfortunately, no longer exists in the new Internet Sharing program, as opposed to the old Modem Link.

Right now, on some pre-AKU3 devices like the Wizard (but unlike, say, the Universal, which also has Wireless Modem (WModem)) Modem Link is the only way to use a PPC PE device as a modem over infrared (IrDA). Unlike “traditional”, “dumb” GSM phones, while these devices are also seen as “modems” for other IR devices when Modem Link isn’t active (I’ve elaborated on this, say, here), they can not be used as modems for actual dial-ups without explicitly starting the Windows Mobile phone in infrared modem mode.

The new Internet Sharing only works via USB / BT PAN as can be seen for example in this screenshot of Internet Sharing – the IrCOMM in the drop-down menu is gone, as opposed to that of Modem Link.

By completely abandoning Modem Link, this only way to connect to the outside world via infrared will also be gone. This means you will no longer be able to use AKU3 devices as infrared modems that don’t have additional programs (for example, Wireless Modem) to be used as infrared modems.

Note that some other PPC PE devices (for example, the HTC Universal) have the IrDA-capable WModem, which, currently, is almost the same as Modem Link (except for some fancy receive / send “LEDs”) and, again, still in pre-AKU3 times, seems to be quite redundant (“why double the functionality?”). This redundancy won’t, however, be the case after moving to Internet Sharing (if and when the Universal receives an official AKU3 upgrade) any more, when it’ll be the only phone app with IrDA capabilities.

What’s the point in sticking with IrDA, you may ask? Why not USB or BT instead? The answer is simple: many, for example, Microsoft BT stack-based Pocket PC devices only have IrDA to communicate, even high-end devices like the Dell Axim x51v (if the latter may not use BT DUN any more because of the lack of the BT DUN support in the modem). The same stands for pocket-sized computing platforms like many Palm OS, Linux and Symbian devices – if they contain BT at all, they are unlikely to support PAN.

With the switch to AKU3, none of these non-BT PAN / non-USB-capable clients will be able to access the Net via a PPC PE / MS Smartphone modem any more via infrared either on devices that only have Internet Sharing and not additional connectivity apps like Wmodem.

1.3 Port forwarding issues, running server-side / like apps

With a decent mobile operator (about 20-30% of them are like so; for example, in the UK – see this), which doesn’t use a proxied (“hidden”) networking approach but assigns the connecting client device a “real”, unique, connectable-from-the-outside-world Internet address, you can use so-called “server-side” applications. Don’t be afraid of this, this isn’t geeky stuff: these include absolutely common programs; for example, FTP clients (with non-passive FTP transfers), IRC applications (DCC send from a device only works with server-like devices), RealOne stream playing, incoming remote controller (Pocket Controller, VNC etc) connections etc. Using (or at least trying to use) these are all very common with non-geeks too.
(Please also see this and this for more info on these questions. I also recommend this for a list of what I mean by “server-like” applications on Pocket PC’s – there are quite a few of them which are REALLY useful even on PPC’s, let alone PC’s.)

This means eliminating server-like functionality support on a PC (or even a Pocket PC) connected to the Net via a PPC PE device certainly isn’t welcome. Therefore, it’s a very important question whether a connected Windows Mobile phone forwards all the incoming requests to the connected client, as was the case in pre-AKU3 times.

While Internet Sharing (that is, the new program that makes it possible to share mobile connections with BT PAN clients) doesn’t offer any kind of configurable port forwarding capabilities, unlike the built-in Windows XP Internet Connection Sharing (ICS) I’ve elaborated on several of my ICS-related articles, Microsoft – very wisely! – has paid special attention to properly implement this functionality.

When an AKU3 device shares its Internet connection (over USB, BT PAN and infrared if the given phone has the Wireless Modem / WModem applet), it puts the client to a DMZ (“DeMilitarized Zone”). Then, all incoming requests will be forwarded to the client. I’ve tested this with both playing RealOne streams over GPRS (on a client Pocket PC) and sending DCC files on IRC from client Pocket PC’s and desktop XP’s (to test the USB connection with the latter).

Note that when internet sharing is active, you won’t have server functionality on the phone itself, “only” on the connected client. This is much smaller a problem than the complete lack of using a DMZ (if Microsoft hadn’t implemented port forwarding via using DMZ); with the lack of DMZ’s, no server functionality would be accessible on the client at all. Of course, when you disconnect the client from internet sharing, on the phone, you will be able to use server-side functionality (listening to RealOne streams etc) again. It’s only when Internet Sharing is actively sharing the connection that all incoming connections are auto-forwarded to the client that uses the phone as a modem.

I’ve also tested the DMZ in “leaked” (XDA-Developers) ROM versions (for the Himalaya, Wizard and Universal – click the links for more info). DMZ works with them too via both USB and BT PAN.

1.4 Convenience issues because of the changes in the Bluetooth networking approach

In addition to the above-explained difference in using Windows Mobile-based phones as modems to access the Net, there are some new convenience issues you must be aware of when using AKU3 via Bluetooth (but not via infrared / USB ). These can be pretty annoying if you’ve always liked the “you don’t need to touch the modem at all when you want to dial in to the Internet” in operating system versions prior to AKU3.

Every cloud has a silver lining, though. In some respects, the new, AKU3 connection model is far easier to use through USB. I’ll elaborate on this in the last subsection.

1.4.1 BT convenience issue one: Firing up Network Sharing on the phone

First, let’s have a look at how the old model (prior to AKU3) supported dialing in the Internet via Bluetooth.

When the PPC PE device is used through the standard (pre-AKU3.0) DUN profile, you don’t need to do anything to the PPC. You only start dialing on the client device and it just connects to the Net. (Of course, if you use it via USB or infrared, you must explicitly enable these modes on the Pocket PC in either Modem Link or Wireless Modem, if the latter exists.)

With the new model and the new Internet Sharing, however, the situation is vastly different (again, only when using Bluetooth - with USB / infrared, the situation remained the same as has been before.) You must power on the PDA, fire up Internet Sharing and start the connection by clicking “Connect”. This means a LOT of additional, manual powering up / clicking you didn’t need to do in pre-AKU 3.0 times.

Unfortunately, you must repeat this (power on the phone, go to Internet Sharing and click Connect) every time you’d like to reconnect to the Net on your notebook or other (PAN-compatible) Bluetooth client devices. That is, the “Connected” state changes to an unconnected one as soon as you disconnect the client. In this respect (too), the new model is a bit more inconvenient to use than the old DUN-based one.

1.4.2 BT convenience issue two: Excess clicking needed on the client that uses an AKU3 Windows Mobile via Bluetooth

As BT PAN connections are not treated the same way as BT DUN connections, on clients that use BT PAN to connect to the Net, you
• generally need more clicks to establish the connection, let it be either the desktop Windows or Windows Mobile clients. (Under mobile/desktop Linux clients, in general, you don’t need more clicks.)
• can’t rely on the auto-connect features of the operating systems under desktop and mobile Windows client OS’es. (Unlike under mobile/desktop Linux.)

For example, on desktop Windows, instead of either relying on the auto-connection OR just putting a dial-up link on your desktop (one double-click to start it and, then, just a single click on Dial ), you must (with Widcomm-based clients) click the My Bluetooth Places icon, then, the Entire Bluetooth Neighborhood icon, then, the given device and, finally, the BT PAN icon for the BT PAN connection to be established. (All clicks must be double-clicks!)

(A quick tip: you can reduce the number of clicks needed to fire up the Net connection. To do this, start up Explorer, go to My Bluetooth Places / Entire Bluetooth Neighborhood / the given device and right-click the BT PAN icon; select “Create shortcut”. It will be created – not on the desktop but under My Bluetooth Places. Now, if you just double-click My Bluetooth Places on your desktop, you’ll be able to double-click the new shortcut icon in there as can be seen in here.)

On (Widcomm-based) Windows Mobile clients, you must click the Bluetooth icon on the Today screen, click Bluetooth Manager and double-click the BT PAN icon of the given modem. All this instead of, say, just relying on the auto-connect feature of “real” BT DUN connections. Pretty annoying, eh?

1.4.3 The good: USB is more convenient than before!

In pre-AKU3 operating systems, you must

1. install the USB modem driver for the phone (and hunt for it if you don’t have it – for your convenience, I’ve mirrored it, along with the HTC dialer app, here should you ever need it) upon the first connection. This is unlike with the pre-AKU3 case, where you must supply USBMDM.INF to it when it prompts for a “Generic Serial” device. In AKU3, upon the first connection, the “Windows Mobile-based Internet Sharing Device” USB driver will be automatically installed by Windows XP
   
   Note that, for this to work, you'll need the latest, 4.5beta2 ActiveSync on your desktop. With earlier AS versions (I've tested this with version 4.1 - it prompted me for the driver for "PocketPC USB Sync"), the driver isn't included (and the Windows auto-update database doesn't contain it either).
   
2. the same stands for the HTC dialer (USBModem_Dialer.exe) – you won’t need it at all in AKU3, unlike in previous OS versions. Upon firing up Internet Sharing, starting the USB mode and connecting the USB cable, the client desktop PC will automatically notice the new network. No desktop-side clicking is necessary.

That is, the new, USB-based connectivity schema is far better and more covenient than the old one.

1.5 My wishes…

While the current model is compatible with the majority of desktop Windows-based clients, clients using other operating systems may encounter problems or full inability to access the Net via AKU3 devices because of the…

• lack of infrared support in Internet Sharing (as opposed to Modem Link), if the given model doesn’t contain Wireless Modem (or something similar)
• lack of USB support on the client side (the case with all non-desktop (mobile) clients (show me a Windows Mobile, Symbian or mobile Linux device with USB host that is also able to use Internet Sharing via USB!) and even Linux or other operating systems on the desktop)
• lack of client-side BT PAN support

Therefore, my recommendation for Microsoft is bringing back the DUN profile in addition to keeping the new BT PAN profile. Both have their place under the sun. Use BT PAN with clients that do support it and use the “fallback” DUN with clients that don’t support it or need convenience (see the previous, 1.4 section on the convenience issues on both the client and the phone of the new, PAN-based model).

I also have some other remarks that would make the new approach far more flexible and usable with very little additional coding need. I really hope the excellent folks at Microsoft reimplement DUN in subsequent AKU upgrades and also consider extending the Network Sharing functionality as explained in the following two subsection so that it is able to share any kind of network connections, not only mobile phone-based ones and, at last, offers almost real BT PAN, not only for accessing the Net.

1.5.1 Let’s share any kind of connections, not just mobile phone-based ones!

Internet Sharing could be made MUCH more useful by letting for sharing any kind of connection, not just the ones present in the Connections. Right now, it’s not possible to share for example Wi-Fi connections (a lot of people are asking for Wi-Fi connection sharing all the time; I answer at least one every week). This is a really big problem and could be easily fixed by, for example, just eliminating (or making it optional: if the user only wants to share a given connection and not the current one) the drop-down “Network Connection” menu in the new Internet Sharing applet and just share the current Internet connection, independent of its type.

1.5.2. What do you need to know about the new BT PAN? Can you use it was a REAL Bluetooth PAN network for, say, messaging and playing?

The answer is YES, which is very good news for all MS BT stack users that have long been longing for BT PAN support for its excellent messaging / playing capabilities. Please DO check out my BT PAN-related articles on all these questions; for example, on 4Talk (chat – see this), MS Portrait (chat, file sending) or BT PAN-compatible games (please see the Multiplayer Pocket Game Bible for some examples).

This all means the BT PAN network in AKU3 is a real network as it uses local IP’s (as opposed to DUN) in the network. This means all LAN-based, BT PAN-friendly applications / games work with it as can also be seen in the screenshot I’ve taken with the great multiplayer game Gold Rush (which worked just great over the AKU3 BT PAN – something not possible with pre-AKU3 devices). That is, the basics are already there: it’s just the interface that could be (slightly) modified by Microsoft, of which I’ll elaborate right now.

Unfortunately, the BT PAN support, while it, basically, works, is a bit more limited in AKU3 than in Widcomm-based Pocket PC’s:

1. You MUST connect to the internet in order to be able to create a BT PAN network between two devices. If you don’t have an Internet connection (or you, for example, supply a connection connecting to a bad APN name), BT PAN won’t work either.
2. Second, not as important as above, only one client can connect to an AKU3 device, unlike with the Widcomm BT stack, where the number of connecting clients isn’t restricted
3. AKU3 lacks the BT PAN client mode (so that a AKU3+ device can (also) join BT PAN’s, not (only) host them). This, along with the second bullet, aren’t very important though as can be very easily circumvented (and it’s in very rare cases that you would need a BT PAN network with more than two devices in it – some mass BT PAN multiplayer games like Gold Rush.)

All in all, while the BT PAN, in some respects, does what it’s supposed to (the internet connection sharing does work as expected, except for the convenience and compatibility issues I’ve already elaborated on), the BT PAN support itself could be made independent of “plain” connection sharing. First, making the BT PAN capabilities independent of connection sharing (that is, decouple PAN from Internet Sharing or, at least, make it available for “generic”, non-sharing purposes) would be very nice. The ability to have BT PAN between devices without an actual Internet connection would really enhance the functionality of the BT PAN as there are a LOT of tasks that can be done via local, internet connection-less networks and require no (in cases, non-existing or very expensive) Internet connection. Hope Microsoft also considers this for future AKU versions.

2. Comparison chart

The following chart (only for advanced users / geeks!) compares AKU 3+, pre-AKU3 and Widcomm / Broadcom-based Pocket PC’s (the latter may also have AKU3 – as Bluetooth is not that of Microsoft, with them, the exact AKU version isn’t important) in three areas:

1. in how they support all (not just plain Internet sharing) the capabilities of BT PAN: can you connect to a given BT PAN server with more than one clients at a time; can you use the given implementation as both a client and a server, is the given BT PAN a “real” PAN network and, finally, is any kind of Internet connection needed for the BT PAN network to work. Note that I’ve already elaborated on all these questions earlier.
2. dialup-related: how dial-up (accessing the Net from other devices) is done (via DUN or BT PAN); is it possible to use the device as an infrared modem, can you run server-like apps on the client and, finally, is any manual intervention needed for (re)connection (again, in pre-AKU3 times, nope via Bluetooth DUN – this was also a real strength of the DUN-based approach)
3. internet sharing-related: what protocols work over the sharing (at this, AKU3 really excels as it shares EVERYTHING, as opposed to third-party, non-OS-level solutions used before as is also explained in “Can I share the Internet connection on my Pocket PC through Bluetooth/Wi-Fi? That is, can I make my Internet-connected Pocket PC into some kind of a Wi-Fi/Bluetooth Access Point?”) and the class of collections that can be shared (in this, AKU3’s solution is definitely inferior to “real” ICS, which can share any kind of connection including Wi-Fi, not only mobile phone-based ones.)

If you can’t see the above chart, the chart is here as HTML

3. Verdict

While the new model exhibits some serious compatibility (and, with Bluetooth connections, convenience) problems, I consider it a very good step in the right direction.

I do hope Microsoft reimplements Bluetooth DUN (which isn't at all complicated because it did exist in previous operating system versions - they will only need to insert back the code used in there) and, preferably, infrared connection in the new Internet Sharing program or, at least, forces Pocket PC manufacturers to supply the Wireless Modem program with all their AKU3 ROM upgrades (also on models that, traditionally, didn't have it - for example, the Wizard) / new models so that infrared dial-in still remains possible.

Also, I hope they go on extending the functionality of Bluetooth PAN so that the Microsoft BT stack, at least BT PAN-wise, becomes a decent alternative to the Widcomm BT stack.

4. Other, recommended links

Use your Pocket PC Phone Edition as a modem for your other Pocket PC's! - a full tutorial - (this explains the pre-AKU3 case)

Can I share the Internet connection on my Pocket PC through Bluetooth/Wi-Fi? That is, can I make my Internet-connected Pocket PC into some kind of a Wi-Fi/Bluetooth Access Point? - this article explains how ICS must be done on pre-AKU3 devices.

UPDATE (11/13/2006): in the meantime, I've scrutinized whether you can "hack" DUN support to the AKU3 MS BT stack with "simple" registry hacking.

Unfortunately, it doesn't seem to be possible for the following reasons:

1. The subkeys under [HKEY_LOCAL_MACHINE\ SOFTWARE\ Microsoft\ Bluetooth\ Services] isn't actively used (and can even be deleted) when clients discover the services of a MS BT stack device.
2. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Bluetooth\SYS\COD, which is a dword with the value 00120114 in AKU3 and 00100114 in pre-AKU3 only describe for clients what kind of a BT device is (is it a phone? A PDA? A desktop computer? A headset? Stereo headphones?), and not the services it offers. This means using the old 00100114 as its value in AKU3 won't help either.

It seems the list of the provided services are returned from the BT-related DLL files, which can't be hacked easily.

Feel free to chime in and to point out if you know a way of (re-)enabling the DUN profile under WM5 (without, preferably, getting rid of BT PAN!)

Discussions of this article: HowardForums

Great! Will post an update to everywhere!

Problem fixed; see http://xdaforums.com/showthread.php?p=1400709

pierro78 said:

sorry for the (probably dumb) question but could you elaborate a little bit on the possible workaround to connect an aku3 device as a BT PAN client to a BT PAN server on another aku3 device ?

Here is the scenario I am interested in : having a HTC Universal (no sim card) connected to the internet thanks to another aku3 device. This other device (probably a smaller device like a HTC Wizard) is connected to the internet through its wan connection and keeps its full internet functionalities.

Thanks !!!

Click to expand...

Click to collapse

I referred to installing the (hacked) Widcomm BT stack (see http://www.pocketpcmag.com/blogs/index.php?blog=3&p=1649&more=1&c=1&tb=1&pb=1 ), which is available for many (but not all!) MS BT stack-based models.

pierro78 said:

Thanks Menneisys for your answer.

So another (probably also dumb) question :
If I buy an Universal and just want to use it as a PDA connected to the internet through, say, my Wizard. Is there a reliable (& not too hard) way so my Wizard also has full internet features enabled at the same time ??
Thanks again !!!!

PS :
I could go for the N800 which has BT PAN client already integrated but I'd like a keyboard and MS Exchange access ...

Click to expand...

Click to collapse

So, you need to use Internet Sharing on the Wizard, so that you can also access the Net on it? Then, install the Widcomm hack on the Universal. See http://xdaforums.com/showthread.php?p=1115973

pierro78 said:

Awesome, I have missed this thread

Click to expand...

Click to collapse

Just make sure you follow all my articles - I've also advertised this thread in several of them