Error 668 Sierra 881 Wireless AirCard ATT 3G

Purchased my AT&T Wireless 3G card about 2 months ago. Has worked flawlessly since then, up until today. Out of no where, when trying to connect with a full 3G signal available, an error message stating Error 668 caused the connection to terminate. I tried the usual problem solving of removing the aircard and reinserting it, restarting the ATT connection manager, and restarting my laptop. Nothing worked, and it continued to produce the Error 668 message.

As I would rather squeeze turnip juice than call AT&T Wireless for any technical support issues, I tried A few Google searches which netted some promising results. While I am not sure exactly what fixed my problem, it is now working again without any hardware replacement. Feel free to try the methods below.

Reinstall the Firmware

  • If you have a different model or Mac OS, you can start at the Sierra Support website
  • Otherwise, visit the 881 AirCard Support Downloads page for Windows
  • Download and run the firmware application, while keeping your aircard plugged into the PCMCIA slot.
  • Some people mentioned that installing the Connection watcher utility from the support downloads page may also help with this issue, but I did not need to use it.

After reinstalling the firmware, I attempted to connect again but still received the same error 668 code. I then moved to this next little workaround.

Install New ATT Connection Profile Using wap.cingular

This is what I think finally fixed my problem, but it did not work without first reinstalling the firmware.

1. Edit connection profiles in ATT Wireless Connection Utility

2. Click the “Add” button on the profile manager window, then select “AT&T” and hit next.
3. Change isp.cingular to wap.cingular, and leave all the other input boxes as is. My result looked like this:

4. Hit next, make sure both radio buttons are select to “Obtain IP Address Automatically” and hit next again.
5. Give your new profile a name, I used AT&T (2). I changed the connection options window to “Automatic” from the default manual, and that seemed to work for me.

6. Hit Finish, close out of the profile manager, select the connections drop down window in the AT&T connection utility, and then select the new AT&T (2) connection profile that we just created.

Hope this was some help to you. Please post in the comments if this did or did not work for you.

28 thoughts on “Error 668 Sierra 881 Wireless AirCard ATT 3G

  1. The firmware couldn’t install because the program “failed to find the device.” So I still had the problem. I spoke with AT&T and I was able to connect at 2G but not 3G. Not sure what to do now.


  2. I cannot thank you enough for helping us. I had no trouble with my Sierra device and my Mac, but my husband struggled for hours with his and his Vaio. After we got partway through the problem by using the device manager and disabling the firewall and anti-virus and reloading the program, it still took what you laid out here to get us up and running. This was very important to us as we are out of town for a week and a half and really, really needed internet access. Thank you thank you thank you!


  3. I have the AT&T wireless card. I can only stay connected for about ten minutes, regardless of what computer I’m on. I brought my aircard into the AT&T shop and was given a new one. Same problems. I was even told I am in one of the best areas for reception. I feel sorry for the people who are in bad reception areas!


  4. I am currently trying the fix described above and while typing this comment, it just crapped out. This really sucks. Now on top of all of the disconnects (I can stay online from 4-8 minutes), now my web pages are hitting “timed out”. I receive a 3G signal on my cell phone, but have never gotten it on my sierra 881.


  5. I use Windows XP on two machines (one laptop one desktop). The first time I installed the card (I have a USB Sierra Wireless Mercury card) on the laptop it worked just fine right away. However, when I tried it a second time a day later, it gave the 668 error. Then I installed on the desktop and got 668 right away. Then I changed isp.cingular to wap.cingular just like you said and it worked on the desktop and laptop.

    I think the error is not b/c of you signal but because of this isp vs wap thing (why ATT can’t get this right is beyond me lol).

    thanks for the solution!


  6. Setting the access point to wap.cingular was what worked for me. Weird that AT&T and Sierra do not explain this on their support pages – would have been helpful to have a big note on the support page for this product since its such an easy fix. Thanks for posting this info.


  7. Thanks a lot. But I have skipped the first step of updating the firmware knowing my device never worked. Then I proceeded to the second step of updating wap.cingular information. It worked just fine I appreciated.


  8. Um, just so you all are aware, the wap.cingular is a different apn(access point name) like isp.cingular. True you may be able to connect to wap.cingular when you will sometimes not be able to connect to isp.cingular, BUT, the connection speed is much slower then is capable of being produced on the 3G aircards.
    Secondly, uninstall all of your drivers, uninstall ACM, and look up what is called the “clean uninstall” utility for ACM (this will provide a more through uninstall of the program and it’s registry entries). Find another internet connection (wifi) and download the newest ACM version from, or locate your card manufacturer’s software (3G watcher, GT connect, etc.)
    If you live in bumbleskunkville, you really shouldn’t expect a solid/fast connection… period.
    And lastly, it doesn’t matter what your phone says about getting 3G or EDGE, or whatever. The phone side of the tower is different then the data side.
    This is a great fix for temp sake if you can’t get anything else to work, but you shouldn’t be posting stuff on the net that basically locks people into a crappy connection. Wap.cingular is the apn used for MediaNet (which is not fast).

    Good luck, and next time, even if you think AT&T tech support sucks, you may want to call them to get your issue actually resolved, or get your card replaced, instead of taking advice that you do not fully understand. It’s like messing around in your registry to fix something, when all you need to do is do a System File Check (sfc /scannow). Not meaning to sound like a bag of trash, but this advice is not a real solution in any way.


  9. You are a miracle worker..I was ready to throw this thing out the window! I had to do one extra step, because I was using 2 other Aircards while I was trying to figure what was wrong with this one, I had to enable it in my Adapters as well as in my modems, once I did that, it connected right to ATT2 which I set up before enabling, and all is fantastic! Thank you for such a easy to follow and extremely valuable suggestion!!


  10. Your solution worked perfectly for me, thank you. I had to hunt a bit for the site because the link in your piece seems to have moved but once I found it updating the firmware and creating the new connection were a snap.


  11. Just bought a reburbished Sierra/ATT Mercury and getting ready to leave for a trip in a couple of days. I freaked out immediately when I got the Error 668 after the driver was installed. The help section doesn’t list the error 668. But thank you, thank you, thank you…I followed your instructions and its working great for the moment. I could only hook up to the 2G network but that may be because of the location I am in but I am going to a major U.S. city and that will put it to a real test. 🙂


  12. well i am going off grid, tomorrow! and i really need my aircad to work. i just got the laptop (used) and aircard, the only thing i’ve gotten is 668. So now I folow these directions and to my dismay the service type is greyed out and the access point name will not allow me to change it in any way. so what now and if u can help please do so asap thanks ever so!


  13. ok ok i take it all back. went to the correct screen this time and did have access and changed it and am now online!!! u are a genious and u have made my day and then some. kiss!


  14. Tried your fix, but when I type in wap.cingular and click next it tells me to choose a different APN. It wont let me use that one. What now?


  15. It happened to me too. I found it only remove all data in Access Point Name field and leave it in blank. It works for me now.


  16. The link to download the firmware was not working so I skipped that step. I followed the rest of the instructions and the card worked great when I tried it the first time. I’m using the card right now while posting this comment.
    Thanks for you help.


  17. Thanks dude! Worked great. I did hit the same issue as Ranada/#19 in that the ATT Connection manager won’t let me type in wap.cingular. My fix was to uninstall ATT Connection manager and download the generic 3G Watcher program from and it lets you enter that and works like a charm.


  18. Awesome… this blog post worked and solved my problem. 1st I updated the firmware from Sierra wireless, then updated the connection settings. Problem resolved. Thanks much for saving me previous time.

    I’m using Windows 7 64-bit beta 1.


  19. what i’ve done look like ridiculuous
    after trying everything, including re-create profile.
    i got sick of it, i hit the air card 3 times
    then try to connect again
    connect again….
    till now i still confuse


  20. Hi, I have the att communication manager. It does not look like the pic you provided above. I can’t find the ‘add’ or ‘connection profiles’. Is this something I can find w/i my computer settings? I am trying to use the sierra wireless internet 3g shockwave device.I have already uploaded the watcher. The device never loads all the drivers correctly. Att tech is of no help. thank you.


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