Application Cross-talk in a wireless environment

[sybs01]

I'm not sure if this is phenomenon unique to Alpha5v10, but perhaps someone has run into it.

I developed an application for a remote customer that I tested using a "hard wired" network. When I delivered the application, the customer has reported that, when simultaneously entering data into the Alpha5 application on two machines, data from one appears in the other, then locks the one of the machines. The app's are using the Alpha5 runtime.

It would seem network related, but I wanted to rule out any possibility of the application introducing these issues and solicit suggestions, if anyone has any, for running down the problem.

[Tom Cone Jr]

Re: Application Cross-talk in a wireless environment

Bill, I remember Cal Locklin mentioning something similar. Two users, both with wireless keyboards, inputs from one keyboard showing up on other machine's screen. You might search for message board threads discussing "wireless" and /or "keyboard" if you think this might be your customer's situation.

[sybs01]

Re: Application Cross-talk in a wireless environment

Thanks Tom - I'll check tht out.

although, my situation is a wee bit different, in that it appears to be the NIC's somehow - we're not using wireless keyboards.

But, that gives me a starting point. Thanks again

[aRob]

Re: Application Cross-talk in a wireless environment

a remote customer

Is that someone connecting over the internet?

Architecture? How is the hardware/software connected?

[Peter.Greulich]

Re: Application Cross-talk in a wireless environment

As I recall, Cal's wireless keyboard problem was that one of his clients had mixed up their keyboards - i.e. machine A had keyboard B and vise-versa. Your problem is different, although I seem to remember that someone else had experienced a similar phenomenon to yours quite a while back.

[martinwcole]

Re: Application Cross-talk in a wireless environment

I've had the problem where 2 users sitting close to each other both had wireless keyboards, and both PC's were getting imput from both keyboards. Apparently, there needs to be something between 2 wireless users to block the signal.

[CALocklin]

Re: Application Cross-talk in a wireless environment

As I recall, Cal's wireless keyboard problem was that one of his clients had mixed up their keyboards - i.e. machine A had keyboard B and vise-versa. Your problem is different, although I seem to remember that someone else had experienced a similar phenomenon to yours quite a while back.

Actually, the problem I saw was essentially the same as Martin's. A user with a wireless keyboard was working next to someone with a wired keyboard and the keystrokes from the wireless keyboard were appearing on the other system. Moving the wireless keyboard a couple feet further away solved the problem.

[sybs01]

Re: Application Cross-talk in a wireless environment

Is that someone connecting over the internet?

Architecture? How is the hardware/software connected?

Hi Rob,

The only significance of the term "remote" in this instance is that they're in Chicago and I'm in the LA area. The system they're running is on a local Class "C" P2P network - no master "server", no LDAP/ADS, and no Internet required.

The "master" A5v10 DB's reside on a single Dell T3400/QuadCore with a standard hardwire Ethernet NIC, and live on a SATA mirrored drive. Users connect via a standard "all-in-one" router - a Cisco/Linksys "WRT54GS2," which supports a NAT firewall, 4 RJ45 ports, and wireless.

The "clients" live on two T3400 Dual Core machines, each with both RJ45 and wireless NIC's, running A5v10 run-times using shadow DB's.

The wireless connections find the router OK, but there is some spotty connectivity - for troubleshooting purposes, everything was collocated.

So, the trouble scenario is, when attached via a CAT6 cable, the application performs flawlessly. When connected "wirelessly," it appears that there is a problem with the signals "commingling"; that is, it manifest itself as both session's keyed information "appearing" in the data entry form of the other, then after a bit, one or the other machines just locks up tight.

And of course, the technical observation of my client is "this software sucks!"

My mission, Mr Phelps, is to convince them that it has nothing to do with the "software" and appears to be either some issue with the router (doubtful) or the wireless NIC's (more likely). However, I thought it prudent to rule out the application or A5 before becoming adamant and then later having egg on my face.

The Dell "support" forum offered the suggestion (from a Junior Specialist - an oxymoronic title if I've ever heard one) to "uninstall and re-install the application". When I pointed out the dubiousness of this suggestion on the basis that it works fine when wired, he replied that it's probably the router. Linksys hasn't proffered a suggestion as of yet.

Anyway, someone mentioned that perhaps a fellow Alpha traveler had encountered this situation, but my attempts to form a crafty enough search phrase to successfuly find the post has been so far fruitless.

Any suggestion in this regard is greatly appreciated, but again, thanks to all for responding to my post. I value and appreciate your time.

[martinwcole]

Re: Application Cross-talk in a wireless environment

Well, this is a different kind of cross talk issue. Until recently, I adamantly advised all clients to NOT use a wireless network. (Until recently, I had never seen one work.) But I have one client with a wireless network, and it works very well. So I am now thinking the problems are in the installation and configuration of the network, as well as all the related hardware.

And given that many enterprise organizations (like large hospitals such as Baylor in Dallas) are using wireless networks, and many with additional wireless devices like keyboards and mice - successfully - I am even more convinced they need someone very experienced in setting them up.

[sybs01]

Re: Application Cross-talk in a wireless environment

Well, this is a different kind of cross talk issue. Until recently, I adamantly advised all clients to NOT use a wireless network. (Until recently, I had never seen one work.) But I have one client with a wireless network, and it works very well. So I am now thinking the problems are in the installation and configuration of the network, as well as all the related hardware.

And given that many enterprise organizations (like large hospitals such as Baylor in Dallas) are using wireless networks, and many with additional wireless devices like keyboards and mice - successfully - I am even more convinced they need someone very experienced in setting them up.

Hi Martin,

You may be right - and I too am not a big proponent of wireless unless absolutely necessary. It was sort of forced upon me by the client and I let go of my better judgment because of the simplicity of the design and the fact that I could have all the items shipped to me first, lab test it, and ship the monstrosity out "kit-and-kaboodle" as they say.

In the movie treament of "13 days," JFK says, "Isn't it a sin to ignore your own better judgment?" I think in this case, I have to agree.

The striking thing is, I had this thing humming in the lab and the instructions to reassemble so simple that it defied my imagination that it could be assembled improperly so to introduce this kind of situation. (BTW, this is why I try to resist hardware engagements altogether beyond recommend/design - if I don't make the parts, I can't honestly warrant them, but you're required to anyway in those situations. I've also had sysadmins/techs tell me they don't trust programmers with screwdrivers! ha ha)

Anyway, thanks at least for what I see as moral support for my original feelings on the matter. Be well

[Chris.Tanti]

Re: Application Cross-talk in a wireless environment

I am far from an expert in networking, but how about switching to a fixed IP address on the two workstations.

How is the IP connectivity set up on the hard nics and wireless nics, are they both set up for dhcp?

Also, try dropping the shadow db and running a shortcut direct from the source folder. Never been a fan of the shadow db method (its probably improved since I last used it)

[aRob]

Re: Application Cross-talk in a wireless environment

I don't think that this problem has anything to do with Alpha. Seems to be a configuration problem. It could be something with the IP address. I would setup the router as a DHCP server and have the NICs get the IP address automatically. The router should be an access point so the network mode should be 'Infrastructure'.

These days, installation programs do a good job of setting up wireless networks so there isn't that much to change. They are pretty easy to install.

The only downside of wireless is the greater potential of getting disconnected and getting hacked. I don't see any reason why it shouldn't work.

[sybs01]

Re: Application Cross-talk in a wireless environment

I don't think that this problem has anything to do with Alpha. Seems to be a configuration problem. It could be something with the IP address. I would setup the router as a DHCP server and have the NICs get the IP address automatically. The router should be an access point so the network mode should be 'Infrastructure'.

These days, installation programs do a good job of setting up wireless networks so there isn't that much to change. They are pretty easy to install.

The only downside of wireless is the greater potential of getting disconnected and getting hacked. I don't see any reason why it shouldn't work.

Thanks Rob,

Yes they're receiving their IP from DHCP. As I mentioned, I had it working swimmingly here. I think I'm to punt and call in an IT Networking co. I'm familiar with in that area to look at the setup and config, as well as do a wireless evaluation - they take signal strength readings etc and evaluate whether a signal booster or repeater of some sort is in order or wireless just isn't a good ROI.

Thanks Rob and everyone for your helpful comments.

[martinwcole]

Re: Application Cross-talk in a wireless environment

Be sure and check for wireless keyboards and mice - I had a scenario where the user fibbed, fearing if they answered yes they would lose it. And as soon as we got rid of the wireless keyboards, the issue disappeared.

[csda1]

Re: Application Cross-talk in a wireless environment

Hi Rob,

So, the trouble scenario is, when attached via a CAT6 cable, the application performs flawlessly. When connected "wirelessly," it appears that there is a problem with the signals "commingling"; that is, it manifest itself as both session's keyed information "appearing" in the data entry form of the other, then after a bit, one or the other machines just locks up tight.

See my tips on Alpha Five Record Locking here. I surmise that the less than perfect wireless connection is breaking the process of locking, a crucial aspect when not using True client-server. One thing to try is to use the wireless utilities (typically come with the NIC cards and/or windows) and see what other networks are in the immediate area, and then change to a less used channel.

An alternative to wireless is a Powerline adapter that feeds ethernet through the AC wires. My experience is that they are very reliable in many typical offices.