IXRTT Security concerns

We use a Sierra Wireless 555 aircard inside a device we build for wireless transactions. We discovered that in a 11 day period someone was able to send over 498MB of data over this card. The problem is that this was a development unit and was turned off or out of the ubit when some of the transfers took place. The logs on the SA card software show no connections or data transfers but I did get a bill for 3K from the cell carrier.

!XRTT is the latest and greatest digital "secure" network so needless to say we are concerned about the possibility of a security hole somewhere in the system.

Has anyone got any ideas how this could have occurred? We have been racking our brains trying to understand it without success. BTW the cell carrier refuses to provide us written details of the transfers.

I too use one of these cards but before we got it, I asked about the security around it here. Check out the following thread:

http://www.antionline.com/showthread...hreadid=255859

Given what was said in this thread we made the decision to purchase the card. Now, again, given what was covered in this thread, I don't believe your wireless cell connection was hacked. I believe the real problem is with your provider and their accounting system. Now if you can't get them to provide you with details about the transactions, maybe let them know that you have to get law enforcement involved because you didn't do it and someone is attempting to steal 'air' time from you. This may get them to provide more information, if not, get law enforcement involved , they should be able to get the records from your supplier.

Good luck.

Cheers:

Thanks for your input. BTW we are also located in Canada and this was a Bell unit. They finally pulled the invoice but insist that it was legitimate even though we were able to validate that the downloads didn't go to that card and that it was in fact out or shut down. One of their techies let slip some of the d/l info and it showed us downloading almost 400mb in 3 hrs which is pretty good for this card.

Anyways in the very back of my mind is this nag that either Bell has been compromised or there is a problem with these cards. We are implementing a new app that needs an aircard but we are going to use the 750 GSM version on T-Mobile rather than the 555 1XRTT version/ If it blows up I'll be back asking questions.