IRDA connection does not work (error 770)

[lorenzodv]

Hi.

I am trying to connect my notebook pc (Windows 95, built-in IR port) and my desktop (Windows XP Pro, ESI Jeteye PC attached to COM1) together. Befor updating the desktop to Windows XP, I could always connect with Windows 98, through the "virtual" COM port. Now, with Windows XP, the virtual COM port is gone and when I try to connect it returns error 770, saying the remote computer refused the connection: this is weird, since the two PCs "see" each other and even communicate their own network name. How to get rid of that error and finally connects the systems again?

Thanks.

 

[dilettante]

Substantial changes were made in IrDA support for Windows 2000 and Windows XP.

See:

http://www.microsoft.com/hwdev/tech/network/infrared/WinXP-IrDa.asp

You may need new drivers, or you may need to turn off something the article above calls "Image Transfer utility" which may be hogging the virtual COM port.

IT still may not work at all. See:

http://support.microsoft.com/directory/article.asp?ID=KB;EN-US;q252795

This article offers a Win2K fix, but says:

"NOTE: This update still does not allow for mapping of infrared ports to a Virtual COM port. The added support is specifically for IrDA-enabled mobile phones. This update makes the IrCOMM support identical to Windows XP."

This all seems to be related to a security vulnerability in 98/Me.

On the other hand maybe all that is required is a new driver?

 

[lorenzodv]

SUCCESS, thanks dilettante! Those articles pointed out that WinXP has no IRComm support. So, I searched for a third-party IRComm drive and, after installing it, the connection works.

HOWEVER, although I can connect with WinXP as a guest and Win95 as the host both over IR or parallel cable, I still can't connect with WinXP as the host. I feel this is somewhat related to permissions XP gives to users on incoming connection... will someone clear my doubts about that?

Thanks.

 

[dilettante]

Yeah.

As Microsoft gets beaten up in the press about security vulnerabilities, we'll see feature after feature closed off or removed. This was one of them. In this case an IrDA "Denial of Service" exploit.

I have successfully used XP as Host and Win95 as guest over parallel DCC using TCP/IP as the transport.

What symptoms do you see when you try this?

For example, can the 9x guest ping the XP host using its IP address but not its computer name?

What are you specifying for IP addresses on the connection (at the XP end)?

On my Incoming Connection's TCP/IP settings I said:

[x] Allow callers to access my LAN

(*) Specify TCP/IP Addresses
    From: 192.168.123.1
      To: 192.168.123.10

[ ] Allow calling computer to specify its own IP address (i.e. NO).

 

[lorenzodv]

My settings for TCP/IP are the same. However, the PCs does not even connect: I use DCC on the Win95 guest to call the host PC, but WinXP does not give signs of activity. This is only an appearance, hoever, if I read the log file for the IR COM port, I find that lines are added each time I try to connect.
Here is part of the activity log: each connection attempt from the client generates these lines:

01-23-2002 22:31:21.770 - 115200,8,N,1, ctsfl=1, rtsctl=2
01-23-2002 22:31:24.454 - Initializing modem.
01-23-2002 22:31:24.454 - Waiting for incoming call.
01-23-2002 22:31:24.584 - Passthrough active
01-23-2002 22:31:24.644 - Passthrough inactive
01-23-2002 22:31:24.644 - 115200,8,N,1, ctsfl=1, rtsctl=2
01-23-2002 22:31:24.724 - Initializing modem.
01-23-2002 22:31:24.724 - Waiting for incoming call.

(I translated it from Italian for your convenience, thus some text may not correnspond in the English version of Windows)

I wonder what that "Passthrough" thing is and why it just stops receiving the connection. I will soon post the log from the client PC... maybe it tells us more!

Note that this is the log for the COM port, but for the LPT port the things are going exactly the same way, so it is a generalized problem (timeouts maybe?).

 

[lorenzodv]

An update: I managed to get the IR serial connection to work with XP as the host! After trying several settings for baud rate and flow control (None, Hardware, Software) I was getting strange DTR and hardware errors in the log (that had became richer than the logfile I previously posted).

Then, I discovered a very strange thing: actually the connection with XP as the host DOES work ONLY if, while the client is attempting to connect with DCC, I open the properties page for the "Cable between 2 PCs" virtual modem in the Device manager! Note that, if I am already in the properties, it does not work: I have to enter the properties WHILE the client is attempting to connect! This is really a weird behaviour... what may be the cause?

Also, what settings do you suggest for flow control and FIFO buffer?

Now, I can share host's and client's files and printers, but still can't do ICS. I opened another thread abuot that (this was becoming OT), see if you can help there.