I've gotten the 875U AT&T USB Sierra Wireless Aircard to work. Fortunately the needed Sierra drivers and scripts already came installed on the EEE PC.

Sierra does not support LINUX but provides links to drivers and instructions here:
http://www.sierrawireless.com/faq/ShowFAQ.aspx?ID=607

Remember, the driver and scripts are already installed. Here's the only change in the scripts that seems to be necessary:

Use the adminnistrative console or use a regular terminal window and SU to root. In the ./etc/ppp/peers directory you will find a file gsm_chat. Using a file editor such as VI to comment out this line by putting a # in front of it:

OK   'AT+CGDCONT=1, "IP","internet"'
changes to:
#OK   'AT+CGDCONT=1, "IP","internet"'

Then uncomment this line by deleting the # in the front of it:

#OK   'AT+CGDCONT=1, "IP","ISP.CINGULAR"'
changes to:
OK   'AT+CGDCONT=1, "IP","ISP.CINGULAR"'

That's it. The Sierra Wireless page has you issue this command:

/>chmod a+x ip-up.local ip-down.local

That does not seem to be necessary. In fact, I've been unable to get it to work when I've issued that command.

You should now be good to go. I recommend turning off the WI-FI before you connect. I've found that this sometimes, but not always, causes a problem in connecting with the AirCard. To connect you need to be logged in as root (pppd will not run otherwise) and issue the following command:

/>pppd call gsm

Here are the limitations that I've found thus far. To make this really functional you need to be in full desktop mode rather than in the tabbed view. For me, anyway, trying to do this in the tabbed view creates DNS problems. You are able to connect but in order to get to a website or server you need to know the IP address, the URL doesn't want to resolve. I've no idea why this is. Maybe it could be that some drivers or other items are not loaded when booting up into tabbed view? Not a clue.

Second, once you issue the "pppd call gsm" command and the modem connects you do not return to a command prompt. Thus far any attempt I have made to get back to a command prompt has resulted in the modem disconnecting. Just leave the terminal window open and don't close it until you're done with using the modem. If you need SSH or FTP or some other functionality from a console just open another instance of the console or terminal program. FIrefox or any of the other desktop programs should work fine now.

There's no visual to see signal strength or the type of connection you have (3G, Edge or GPRS). The Sierra page details the command line AT commands you can issue from a terminal window to determine this. By using the 'pppd call gsm' command it appears that you are automatically connected to whatever is the fastest connection available.

Anyway, this seems to work pretty well. With 3G I've been able to average around 1.7 Mbps down and around 300 Kbps up on a regular basis. While the U875 has a battery it most likely draws some power from the EEE PC as well. I've not yet had the chance to test how the EEE PC battery life may be affected by the use of the AirCard. As is usually the case with such devices disconnect it from the EEE PC when not in use or when the computer is turned off.

NEW INFO

I've recently have begun to have DNS problems with the above method of using the U875 card. That's indicated near the bottom of the output you get from running the "pppd call gsm" command if you get the following IP addresses for DNS:
primary DNS address 10.11.12.13
secondary DNS address: 10.11.12.14

The problem appears to be that something is not happening correctly in retrieving DNS server info from AT&T. I was experiencing this problem on rare occasion but now it seems to be happening all the time. You can still go out on the web because you are connected. The problem is you need to know the IP address of where you are going because domain names aren't being resolved.

It took me a bit to find a workaround for this. Someone else may come up with something more elegant but here you go:

The nameserver infomation is contained in the resolv.conf file in the /etc directory. This file is changed dynamically when different types of connections are made by the resolvconf program called by the various scripts etc. that establish connections. In addition to whatever information gets fed into resolvconf the resolvconf program also builds the resolv.conf file from several elements in the etc/resolvconf/resolv.conf.d directory. There should be four files in that directory: base, head, original, tail. The file you want to edit is base. Most likely it is an empty file at the moment.

The base file contains any information you want to always be written into the resolv.conf file whenever it is written by the resolvconf program. What you want to do is to identify a couple of nameservers that will always be available and could be used regardless of the connection that you have. I recommend the nameservers associated with the OpenDNS project. (https://www.opendns.com/)

Using vi or whatever other editor you desire add these two lines to the the file: base

nameserver 208.67.222.222
nameserver 208.67.220.220

That's it. Quit your editor and save the file. The numbers are the IP addresses of the OpenDNS nameservers. From now on the OpenDNS servers will be your preferred nameservers for whatever connection you make, whether it is with the Sierra modem, WiFi, LAN, etc.

Once you have done this the next time you try to use the Sierra modem you most likely will receive the same bad DNS information at the end. However, if you then check your resolv.conf file in the /etc directory it should look like this:

nameserver 208.67.222.222
nameserver 208.67.220.220
nameserver 10.11.12.13

Only three nameservers are supported here and the bad one obtained from running the script just gets appended to the two good ones that came from the base file you edited. These nameservers should work for any type of connection you make. One problem area might be if you are using a LAN connection in a corporate environment where the company runs its own DNS servers and you are firewalled or otherwised blocked from accessing a publically accessible nameserver. In that case just re-edit the base file to a blank file again and remember your previous edits for when you want to use your Sierra usb card again.

Like I say there is probably a more elegant solution to the DNS problem but for now this seems to work.

Last edited by zinyman (2007-11-30 3:24:54 pm)

Zapata wrote:

Is the Sierra Wireless Aircard 875U USB 3G modem for AT&T Wireless working fine now??

Yes!

schreibercele wrote:

Do you know if the 881USB will also work and if so will the installation be the same..?.Am totally lost and very non tech and waiting for a friend to try it...But, as much information that I have ahead of time will help her/me.

I believe that you will need to update the Sierra driver included in the Eee PC Linux distribution for the 881U. You could try plugging your modem into one of the USB ports to see if it will be recognized on the off chance but most likely you will need the patch.

According to the Sierra knowledge base here:

http://www.sierrawireless.com/faq/ShowFAQ.aspx?ID=1077

the Sierra driver version for Linux kernels 2.6.21 and 2.6.22 need to be patched for TRU-Install devices like the 881U. The Eee PC has a customized version of 2.6.21, 2.6.21.4-eeepc. The download for the patch and instructions for installation are available at the link above. Since you say you are very non-tech I would highly recommend that you let your friend take care of installing the patch.

Once the patch is installed and the 881U is successfully recognized I believe if you then follow my instructions above, assuming you are on AT&T, you probably will be able to get the modem to work.

You can put me on the list. Same here, days and days trying to install a sierra 881 (AT&T). Compiling kernel adding drivers, applying patches....not a clue, trying to follow instruction unfortunately all of them are for Linux experts..The commands don't work, the files are not found.. ...I'm a windows person...now I can see why MS has capture the market even though Linux, Unix..are much better operating systems. Any way, I hope someone can feel our pain trying to transition from Windows to Linux and help us understand a little bit about compiling kernel and installing these drivers....Remember, write it for dummies...

Well, I have tried just about every solution written up out here about how to get a 875U working with EEE PC (mine is a basic 2g surf - no mods) and the best I can do is get the 875 to dial and connect, but it never obtains either an IP or DNS to work with. It took me forever to figure out that going into ATT/Cingular as my network provider (I have a MediaNet data account) that I had to bury the user (wap@cingulargprs.com)  and password (cingular1) information in the chap-secret and pap-secret files and leave the NOAUTH option in the GSM script. Otherwise I couldn't even get a basic connect going. So, what am I missing? I have added no compression commands to the GSM file as well (since the requests for compression were rejected at APN point). All I get back is a series of DNS strings for my local machine 10.0.0.12, 10.0.0.13,10.0.0.14. I have overwritten the resolv.conf file with the Open DNS addresses advertised all over the place. 208.67.220.220 (and XXX.XX.222.222). That has done nothing.
Have considered just going with XP......(then I could just use the Sierra Watcher App). But that turns out to be another long, up hill, climb that I don't think I want to try and bridge.

So, any other solutions lurking out here? I ran across and app called  launch2net (nova media) which is supposed to give a front end to the Sierra USB Cards (much like Watcher on Microsoft and Mac machines). When I downloaded the demo, however, it was a *.deb package and didn't seem to unpack correctly on my machine. Anyone heard of this and tried it?

I am really running out of ideas here.

RJO