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View Full Version : Pass Through while Active Synching over WLAN


AndrewShuttleworth
04-16-2003, 08:17 PM
Is it possible to use Pass Through to access the internet whilst connected to Active Synch over a (W)LAN? It works fine with a USB synch but I can't get connected in this case. Are there any special settings required? I think I have all the settings correct, but if anyone has a double-checklist I'll double-check :-)

Thanks in advance for the help.

Andrew

Janak Parekh
04-16-2003, 08:23 PM
Huh? Why exactly would you want to do this? Aren't you already setup so that if you're connected to the WLAN, you're connected to the Internet as well? I thought passthrough is only designed for USB...

--janak

AndrewShuttleworth
04-16-2003, 08:33 PM
From what I understand of the non-user friendly network settings, in the last drop down box I have to specify whether I want the network card to access the network or the internet. Seems you can't do both at the same time ... unless I'm mistaken. :?:

Andrew

Janak Parekh
04-16-2003, 08:40 PM
From what I understand of the non-user friendly network settings, in the last drop down box I have to specify whether I want the network card to access the network or the internet. Seems you can't do both at the same time ... unless I'm mistaken. :?:
The whole work vs. Internet thing is kind of flaky. I usually set the Network Card to Work, but then I set the Work to Internet Settings, and using that configuration I've done both ActiveSync and Internet access at the same time without using passthrough. That is, if I remember correctly; I haven't done it in a month or two.

--janak

AndrewShuttleworth
04-16-2003, 08:45 PM
An update ... On the settings dialog for the Network Connection, there is a tab for Proxy Settings. I select the first option (rough translation from Japanese is 'This network is connected to the internet', but when I go back to check the options it has deselected itself. The existence of this dialog suggests that I should be able to access the internet using the network as you also suggested.

???

Andrew

AndrewShuttleworth
04-16-2003, 08:59 PM
The whole work vs. Internet thing is kind of flaky. I usually set the Network Card to Work, but then I set the Work to Internet Settings, and using that configuration I've done both ActiveSync and Internet access at the same time without using passthrough. That is, if I remember correctly; I haven't done it in a month or two.

Thanks - that got it! After changing the Work to Internet Settings, I had to change the Network Card back to Work (as it had automatically changed itself to Internet Settings) and then change Internet Settings to Internet Settings. Got to laugh really ...

Thanks for the help.

Andrew

Sven Johannsen
04-16-2003, 09:01 PM
I've done both ActiveSync and Internet access at the same time without using passthrough
--janak

How do you know? If you are on the network (IP from DHCP server, or static on the network), and you have initiated an AS connection, and it is currently connected, and you pull up a web page, how do you know if the packets went straight to your AP, or through AS/Passthrough/router?

In any case, my seetings are Work, WorK, Work in connection manager, and I have the work profile set with the 'this network connects to the internet' checked on the proxy tab. (mine stays that way, BTW) I can both sync wirelessly and access the internet (with or without AS connected) and cradle and sync normally and use passthrough from the cradle. (Axim or Jornada, symbol WiFi on either, or Orinoco on the Jornada)

{Unless I am misunderstanding and you are using adhoc WiFi to a desktop that is sharing it's internet connection}

AndrewShuttleworth
04-16-2003, 09:17 PM
I've done both ActiveSync and Internet access at the same time without using passthrough
--janak

How do you know? If you are on the network (IP from DHCP server, or static on the network), and you have initiated an AS connection, and it is currently connected, and you pull up a web page, how do you know if the packets went straight to your AP, or through AS/Passthrough/router?

In any case, my seetings are Work, WorK, Work in connection manager, and I have the work profile set with the 'this network connects to the internet' checked on the proxy tab. (mine stays that way, BTW) I can both sync wirelessly and access the internet (with or without AS connected) and cradle and sync normally and use passthrough from the cradle. (Axim or Jornada, symbol WiFi on either, or Orinoco on the Jornada)

Regarding the first point, one pointer could be that he is connected to the network even when not Active Synching, but also I thought one of the rules of Pass Through were that you had to have the same info in the middle drop down option on the PPC connection settings and in the Active Synch settings. If this belief is true and if that doesn't match reality then the internet connection must be coming from the network directly, no?

The option you offer above also works for me. I'm going to have to get a mantra into my head to remember these ... 'Work, Work and Work or Internet, Internet, Work'. Now all I have to do is remember to turn the proxy setting back on when I get to the office tomorrow.

I hope someone from MS is reading :-)

Andrew

Janak Parekh
04-16-2003, 10:01 PM
How do you know? If you are on the network (IP from DHCP server, or static on the network), and you have initiated an AS connection, and it is currently connected, and you pull up a web page, how do you know if the packets went straight to your AP, or through AS/Passthrough/router?
I think I wasn't using passthrough because I had several established TCP connections (remote desktop, etc.) when I started ActiveSync. I'd be very surprised if the passthrough grabbed the MAC address of my Wi-Fi network card, did a DHCP request on that MAC address, got the address, and the Wi-Fi card simultaneously did a DHCP release, and all the connections bridged over seamlessly.

Moreover, now that I think about it, I'd be amazed at ActiveSync if it seamlessly set up passthrough for another reason -- it's a pain networkwise, because you'd essentially be running TCP over AS over TCP, and if all connections on the Pocket PC were subsumed by the passthrough, you'd by design lose the underlying TCP connection, terminating the ActiveSync process immediately. You'd have to set up some very clever routing to work around that, if I read it correctly. I also believe that's the reason I thought passthrough doesn't work, by design, on a network ActiveSync session.

If you have documentation stating otherwise, do let me know, as I'd be very curious to see it. :)

--janak

Sven Johannsen
04-17-2003, 12:30 AM
OK, here is the situation. I have my Axim with a Wifi card in it, off the cradle. I tap sync in AS and it syncs. bedele-dep, bedele-bop, and the desktop AS window shows Connected. So obviously I got an IP address from my DHCP server, My WINS server is resolving the partner PC name to IP, and I sync.

Now, I open PIE and tap PocketPC.com at the top. (after the silly on device page) whoosh I am at www.microsoft.com/mobile..... All the while AS is still connected. So...is it using AS passthrough to do the internet junk, or is it going straight to the gateway (AP/Router) and out. Interestingly I have the little network icons showing in the system tray on my desktop for the 100Mb wired connection. Everytime I tap on a link on the PPC, the little computers light up blue, indicating ethernet traffic. Only thing accessing the net is the PPC, via AS, via pass-through it would seem.

Just for completeness, I can also stop AS (Not Connected on the desktop) and still get to all the web sites I want. In this case though the little computers in my system tray do not show any ethernet activity. So it would seem, without an AS connection, the hardwired port on my desktop is not being used.

Short of buying a real lan sniffer, I know of no good way to find out the source IP of the packets leaving the house. I'm not sure if the pass-through ones would show them coming from the 192.168.55.101 that AS assigns the PPC, or the desktop IP (which is really acting as a NAT router), but it would be distinct from the IP assigned directly to the PPC by my DHCP server. So you could tell if it was a pass-through or a direct packet. Empirically, though, based on the wired lan activity indicater on my PC, if AS is connected, it seems to use pass-through, if not, it goes direct.

Janak Parekh
04-17-2003, 01:29 PM
Short of buying a real lan sniffer, I know of no good way to find out the source IP of the packets leaving the house.
The best way, I think, would be to run a packet sniffer on the PC itself. I'll have to play more with this when I get a chance (and when I set up a WLAN-enabled Pocket PC again; I'm using a PPCPE right now). Thanks for the feedback though, it raises some interesting questions.

--janak

Sven Johannsen
04-18-2003, 03:45 AM
It does, doesn't it? It sure seems that it is using pass-through if I have AS connected, based on the traffic indication on my desktop. That indication isn't there if I disconnect AS. Be interesting to confirm, and then wonder why.

gwinter
04-18-2003, 11:39 AM
I think ActiveSync does not use pass-through when connected through (W)LAN. Read the last item here (http://www.geocities.com/grieg_winter/adhoc/index.html#BTQnA) for a very short explaination why I think it is so. I draw this conclusion from my own set-up:

i. Desktop with 2 network cards, wired LAN and wireless LAN. The wired LAN card connects to the cable modem.
ii. Pocket PC with wireless LAN card, connects to the desktop in ad-hoc mode.

At first I leave the IP address assignment to be dynamic, both the desktop and PPC have addresses in the Automatic Private IP Addressing range (169.254.x.x). I am able to sync to the desktop, but cannot access the Internet. I have tried all kinds of settings to no avail. In the end I settled for the Internet Connection Sharing in Windows XP.

Perhaps the behaviour is different in ad-hoc mode vs. infrastructure mode? I'm not sure but I doubt it.

Janak Parekh
04-18-2003, 01:55 PM
Perhaps the behaviour is different in ad-hoc mode vs. infrastructure mode? I'm not sure but I doubt it.
I don't see how that can be the case--why would ActiveSync be programmed to look at XP's wireless network settings?

--janak