Hi all,
I'm brand new to mobile / pocket pc development, I just have a few networking related questios though.
I'm implementing my own blackberry style client/server for my brand new (got it yesterday) XDA IIi.
From what I've read the IP address of a mobile connected to GPRS will change every data session, so even though it has stayed 'online' all day it may have multiple IP addresses throughout the day. How do the blackberry style systems get around this? Is this todo with the IMS / SIP protocol ?
What I'm wanting is so that the mobile phone doesn't have to send any data to the server (apart from an initial hello) and then when mails come in the server can send directly to the mobile. Obviously with changing IP addresses this is impossible unless each time the IP changes the mobile tells the server, effectively you are not really pushing any more then it's more of a poll.
Also one more question on a non-development note, do providers charge for dropped packets or are they dropped normally before their routers so they simply never see them?
BTW I will be releasing the software I'm working on when done so don't fear
Thanks
bump ?
I guess not much known about GPRS / Blackberry workings ?
You can use WAP push to get in touch with the client on a Pocket PC Phone Edition. Have a look in the Phone API at msdn. I think you'll find something there...
Thanks! Totally forgot about checking MSDN ;P
This is possible, I do something similar. But it's difficult.
The IP assigned to your device is in private address space, using NAPT to contact Internet. Therefore you cannot contact the device IP in any way.
You can however open a connection from the XDA to any host on the Internet using TCP. Once this connection is open, it will remain open indefinitely. Or about 30 minutes if no data is transferred.
Once you have an open TCP connection, you can push data down the tunnel in either direction with very low latency. It is up to you to find a suitable protocol to run over your open tunnel.
Several things also need checking:
- Send some data every few minutes to keep connection open.
- Watch for stale GPRS connections. If this happens, remake the connection.
- Packets do get lost. Ensure all packets checked, resend if needed. You can use the TCP 'ACK' packet, or use your own acknowledgement protocol.
If you get it working, it works surprisingly well.
Hope this is of some use,
Ben Clewett.
Related
I am testing BlueFire 2.3.0 client for more than a week now. Overall it is very good - it does its job done. But after running it extensively for a week I discovered several issues with it, mostly cosmetic, but they are really annoying. Especially, if you want to have Direct Push. Those issues are:
1. "Save credentials for auto-reauthentication" does not work - you have to enter your password every time you connect.
2. It does not reconnect on its own, if it looses the connection (i.e. EDGE/GPRS goes down temporarily)
3. Detection of disconnect is not very reliable - sometimes when you loose signal and GPRS connection wants to disconnect, it cannot do it because of VPN still thinks it is connected and prevents GPRS from reconnecting.
4. Extensive use of on-screen push-buttons instead of soft-keys. And soft-keys are mapped to rarely used functions, like About - poor interface design. It woldn't be so bad, if the VPN client was not requiring user interaction to reconnect and authenticate...
5. After several minutes of standby, it brings its window on top of Today screen, kinda like letting user know that he better check his tunnel/connection, because it could be already disconnected... In most cases it is not true, because the unit wakes half the way up every several minutes to check email or send a heart-beat packet, which keeps connection up (this only applies to GPRS/EDGE connection and not WiFi, unfortunatelly). But sometimes the VPN tunnel becomes dead, and you have to click "Disconnect", "Connect" and enter your password again.
Ok, that is my impression about BlueFire VPN client. Now the question is - is there any better IPsec client for PPC (WM5), which allows you to have Direct Push email over IPsec all day long without your intervention to check the connection status and reconnect manually?
Thanks for your time.
Hi!
Where did you get version 2.3?? I just can find 2.2 on their website...
I wasn't able to connect to my uni's Cisco VPN with version 2.2 and had a lot of issues with other VPN clients (NCP and Antha kind of disrupted the connection manager) - so basically I haven't found any client which is working properly. Hope that will change with one of the next versions...
Thomas
DoctorT said:
Hi!
Where did you get version 2.3?? I just can find 2.2 on their website...
I wasn't able to connect to my uni's Cisco VPN with version 2.2 and had a lot of issues with other VPN clients (NCP and Antha kind of disrupted the connection manager) - so basically I haven't found any client which is working properly. Hope that will change with one of the next versions...
Thomas
Click to expand...
Click to collapse
Apparently, even though their web site says 2.2, they are giving out 2.3 here for trial:
http://www.bluefiresecurity.com/orders/
As of other VPNs for me so far:
NCP killed all my connections - GPRS and WiFi didn't work anymore. It is overcomplicated and I had to uninstall it to get my connections to work properly again.
Antha is promising, especially its DPD (Dead Peer Detection) feature, but I cannot connect with it to our VPN server no matter what I do. I copied all the settings from Bluefire, which can connect, but stil no success.
Over the last year I have tried many times to set up my Windows Mobile devices to connect over VPN and then use RDP to manage my clients' sites. To date I have never managed to get it to work. My config is as follows :-
Within Start \ Settings \Connections \ Advanced \ Select Networks
Programs that automatically connect to the Internet use MY ISP
Programs that automatically connect to a private network "My Work Network"
a VPN is configured under "My work network" and the device can connect to this and using vxutil I can ping the server I wish to RDP to - 172.17.3.3
Supposedly the important bit is to add the exception under "Work URL exceptions", I have added 172.17.3.3 in here.
Once the VPN is established if I enter 172.17.3.3 within IE or Terminal Services CLient the VPN connection is still dropped.
If I enter this IP address without connecting the VPN first then the device will not connect the VPN automatically.
If I enter a non qualified domain name such as ids-vs then the VPN is connected but the name is never resolved.
Can anyone shed any light on this, if I could use a local lmhosts file on the device as with XP then I may be able to work around the above. It appears to me though as though the exceptions list is never processed. I did a hard reset last night just in case, but this has made no difference.
I cannot believe that the above can be so complex.
I am using a HTC Tytn and using t-Mobile in the UK.
Any help greatly appreciated since it is driving me totally mad!
I would love to figure that out.
I was trying to connect to my pc at home like this and suffered from all the same symptoms your having. In the end I gave up, mainly 'cause someone told me that I needed another type of data plan to have vpn (at the time I had the $29.99USD plan) in other words it might be your plan, or something to do with the proxies or something, I hope someone would find out what you need to do in order to get this to work.
It's strange, looking around the web there are loads of people that struggle with the setup, but most seem happy once they are told to add the server name or IP address in the exceptions list.
I have ruled out the data plan since I can establish the VPN connection and can see it authenticate on the other end, as well as being able to ping the server on the work network from the phone.
I have just opened a support call with Microsoft as well, but I am not holding out much hope since I think they will point me at HTC. Assuming HTC ever responded they will just point me back at Microsoft!
Well it would be cool if they could help you, I tried everything myself and zilch. I could also establish a connection but as soon as I would try to access a file on my pc it would disconnect. I would try to help you out experimenting on my side again, but I changed my router to a cheap piece of $h.. and now I can't access my pc via vpn..... I really need to get a decent router
This may sound stupid, but I could swear someone told me something about the speed of the connection. If the connection speed is too low then DNS would fail, although that wouldn't explain why we are able to establish a connection, but not access anything else.
OK, I have made quite a bit of progress :-
1) I was using a cab file to configure T Mobile settings on the phone. This was somehow configuring the exceptions list to be ignored. Hard resetting the phone, installing this CAB the problem remained. Hard Resetting the phone and setting up GPRS manually - everything worked.
2) There is a fault with Windows CE 5 routing over VPN - the subnet information is ignored. Hence for example, if your GPRS provider give you a NAT 10.x.x.x ip address and your corporate network uses 10.x.x.x then you can never route to your corporate network.
And what cab file is that? do you know if it's on the extended roms for the t-mo roms? Glad to see your making progress, keep it up.
It was a Cab file for the Tmobile settings. It either came from these forums or over at modaco, can't remember which.
VPN
I was able to successfully use the Movian VPN to connect to my work using my XDA2.Worked fine for 2 years. Apologies, but I can't help with the settings and my work migrated to an M-notes server so I was able to connect without a VPN.
Hi there,
Firstly sorry for posting what I assume is going to be a very simple question . I have very little experience with XDAs but hope to be able to learn fast.
Basically, I have an old XDA that I would like to connect to a server (the server is connected to a broadband router) in my house and use it as a dial-in modem that I can dial into with another Pocket PC type phone. I guess that web access would then cost the price of just the phone call.
Can anyne point me in the right direction please?
Regards,
07734
I remember a few years ago when a friend of mine set up his own server running RAS so he could dial in from remote locations to access his home network.
He had a Windows 2000 box set up with a modem running the Remote Access Service, and that was connected to his broadband router (he was on cable). I tried it out one day to see what it was like, he assigned me a username and password and I logged in normally via my 56k modem like I would to my regular ISP.
However, that was for regular v.90 dialup access - to run a WAP gateway, you'd most likely to need to set up all of the above - and also run software on your RAS server to provide the appropriate gateway for the WAP protocol... I've never done it so I wouldn't know how, but I can't imagine it's as easy as just setting up a dial-in connection as you can do with Windows 2000, but I'm sure you'd have to do that as WELL as perform extra configuration/setup steps.
Best of luck with it, though...
Wap gateway
Thanks for your reply,
A dial-in type system would probably be fine, although doing this though an XDA would be useful. I'm guessing that there is a modem driver available for the xda that I could use to connect RAS to. I am running Server 03 and should be able to set up RAS if there was a modem driver. That would let me use the XDA as a dial in server and would be great.
It would be even more interesting to do it via an XDA acting as a GPRS gateway as it could also potentially be used to send MMS, SMS etc messages. This would require a little programming but again, I'm guessing that there are going to be a lot of tools out there.
For off the shelf servers, I have briefly looked at:
http://tvilda.stilius.net/wapirc/
http://www.nowwap.com/
http://www.kannel.org
I'm not sure how sutable they are (some are for Unix type OS) but they are interesting examples.
The preference would be for some sort of .Net code that I could run on the XDA to setup the server and interface it to other software on the server.
An example of this would be http://www.logixmobile.com but a little expensive for just messing around.
Sorry to bother you again,
I've been looking around (on this site and google) for a modem driver and it does not look like the modem drivers allow for using the XDA connected to a server via USB to allow another pocket pc phone to access said server or the internet via the server using the xda (sorry, I have a great nack of making simple things confusing).
Anyone out there know where I might be able to get the driver/s for this?
Found the problem!
This problem was being caused by the Blackberry Service on my device. In further investigation I discovered that whenever the Media Net connection goes stagnant the Blackberry connection would reestablish & try to check for new emails. The new BIS connection would change my IP to communicate with our Enterprise Server & of course subsequently, Media Net was killed. When I would try & re-establish my logmein connection it would report the new IP which was hung on Blackberry instead of being reset by Media Net & would report as Mismatched for security reasons.
The solution:
Whenever I need to do some work on my desktop remotely I now suspend the Blackberry Service & have now had no problems with logmein, even through reconnects.
Thanks for all the IM's & emails, there were some interesting ideas
_________________________________________________________________
For years I used logmein with verizon's network without problem. But now I'm AT&T & every time my connection resets I get an error stating "Mismatched IP Address" causing me to have to shut down PIE & start over again.
I have read about a broken proxy fix meant for other client laptops & pc's. I have imported my own"broken proxy" reg.value into logmein security registry settings on my Kaiser. However, every time I lose connection, I still have to start over. Anyone else have this error before?
I'vd tried everything I can think of. Any help?
Thx!
i believe it has to do with using wifi instead of edge/3g. I had the same problem when i logged on with edge and then tried to access my computer with wifi after already logging in to the system. I dont know of this will help but i just relogged in and accessed the pc using the same connection type.
negative, it happens using 3G, edge, gprs, etc.
I thought maybe I could enter an IP in connection settings but then I can't connect period.
Hi, I know this is an old thread, but I'm getting the same error message on my HTC Touch HD (Win Mo 6.1) - any ideas as to how the specified solution could be applied to my device?
Thank you.
I'm attempting to use a Windows Mobile 6.1 device (HTC Diamond) for a temporary internet connection for my mail server while my broadband is down (BT cancelled my line in error and do not seem to be in any hurry to restore the service!). Initially I'm using the built-in ICS functionality..
While outgoing connections are fine I do not seem to be able to make in incoming connection. At first I thought this was due to ICS not port mapping incoming connections downstream (in a port forwarding DMZ manor) so I moved to the seemingly very good WMWiFiRouter tool and which is much more configurable in such ways, however still no joy. Further investigation using the useful website whatismyipaddress.com suggests that my connection is actually not a true connection but instead proxy'd (assumingly by Vodafone). Is this correct? If so, assumingly it is therefore impossible to make direct incoming IP connections (TCP or UDP) to devices on a mobile operators network (in my case Vodafone)?
All comments welcome!
Thanks, Simon
To reply / follow-up to my own post..
It seems this is due to a problem with Vodafone providing data connections with a private NAT’d IP address that is routed through their proxies for traffic optimization etc, and not the required (publically addressable) public IP address for incoming connections.
Please see my separate post on this wider issue: http://forum.xda-developers.com/showthread.php?t=478741
had a problem kinda like it trying to make a socket connection from 2 3 gprs devices
did'nt work unless both had static ip's which cost extre
but it worked ok if just one of them were not a 3 grps device
like a normal pc or a gprs device from another operator