Crossloop: VNC without setup.

Since I often deal with support calls from users I have been experimenting with various remote control tools for a while now. My favorite is by far the RDP protocol mainly because of it’s speed. Unfortunately RDP has limited use in phone support situations because it requires the end user to set up port forwarding on their router.

I experimented a lot with VNC but it had the same problem. Someone out there has to set it up, and if my users knew how to do that, we would not need to bother with a remote control app in the first place. Not to mention that 90% of the time they call me from the field, where they have no control over the firewall or router settings.

I also played around with various one-click-vnc solutions. They all use a reversal of roles – the controller runs a server, and the controllee connects to it. This way all the port forwarding would be done on my side. Unfortunately before I started rolling out this service I got a nasty phone call from the firewall d00dz telling me that I definitely should close these ports before we get hax0rd. The powers that be decided that having the ports open to make this work is too risky and so this project ended quite abruptly.

I almost gave up on finding an elegant solution to this problem. Then I found Crosloop. In essence it is TightVnc with a twist – it uses the as a middle-man relay between the server and the client. So you can have two people, sitting behind big scary firewalls launch this app, log in and have a VNC session going on. There is zero setup beyond the initial install that essentially consists of clicking “Next” several times.

The app has two tabs. The host tab generates a semi-random connection number each time you run it. You can give this number to your tech support drone over the phone, and he can type it in the join tab. If the numbers match, the session is opened and he gets to see and control your screen using the vanilla version of TightVNC.


Crosloop claims that it does not monitor the data on their relay hoop, and that it encrypts all the packets traveling between two hosts using a robust 128 bit encryption algorithm. I haven’t tested this with a packet sniffer, but they do seem legit. I can’t tell if the encryption slows it down, because vnc always seemed painfully sluggish to me anyway. Crosloop is no different – no surprises there.

Personally, I really like it. I can totally see using it for some of the annoying tech support calls. It might be easier to have my clueless lusers to install it rather than try to distill useful information from their frightened squeals, hysterical crying, sighing and sobbing. And I’m not kidding – the other day I had a dude basically cry on the phone because he could not figure out how to copy and paste and embedded spreadsheet from one document to another. I almost cried too – I feel sorry for the little dude. It must be hard for him to live in this strange world full of confusing technology. :P

So what’s the catch you ask? There are two catches actually.

First, the tool is windows only. I tried installing it on Dapper under Wine but I had no luck running it. The installation process went through really quickly, but running the software failed every time. Still, I usually have access to multiple Windows boxen at work so this should not be a big issue.

Second, McAfee, Norton and Windows Defender all recognize it as a Potentially Unwanted Program (PUP) and repeatedly warn you during installation. I got 2 warnings from McAfee, one from Windows Defender, and then another Firewall alert asking me to grant the application access to the internet. Apparently TightVnc is on some sort of black-list out there because all these alerts correctly identified ti by name. Go figure.

This would not be a problem for normal people, but you need to understand that most of my cow-orkers are somewhat special. If they are to trigger happy and click OK on any of these dialogs then the installation will fail, or the app will be denied access and then I will have to walk them through the McAfee or Norton options to unblock it.

This just means that you need to closely supervise the installation process, and make them read every single popup dialog back to you.

Still, it is hell of a tool. Not even mentioning that it is completely free – even for commercial use, which makes it ideally suited to my needs.

[tags]crosslop, vnc, tightvnc, rdp, remote desktop, remote controll[/tags]

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5 Responses to Crossloop: VNC without setup.

  1. bob UNITED STATES Mozilla Firefox Windows says:

    I tried vnc with a free download utility called trate on, it works fine, and very easy to install. You just install trate, then it will let’s you pass nat router and firewall.

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  2. Luke UNITED STATES Mozilla Firefox Windows says:

    Care to leave a link bob? I’d love to try it out. Sourceforge hosts about a million products and googling for trate didn’t give me any good results.

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  3. Stephane FRANCE Mozilla Firefox Windows says:

    They also provide a way to get paid for your technical support (through paypal) … I’m going to try that even if I’m a bit dubious :-)

    Thanks introducing this tool to me !


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  4. Sufyan Ghori Google Chrome Windows says:

    Is there any way that client only need to run the client file and no need to enter the connection number (entered by default) ??

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  5. Eugene RUSSIAN FEDERATION Mozilla Firefox Windows says:

    This is also good.
    The software works well, Ammyy Admin doesn’t require installation or specific config, works behind gateways NAT as well as within one LAN.

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