Using the Wireless Modem Ricochet

By Mark Nielsen

References
Introduction
Getting Ricochet
Installing the Ricochet modem
Setting up a firewall for your network
Why use the Ricochet modem?
Conclusion

References

Metricom modems support in Linux. This is the only place I found that explained how to install the faster modems.
If this article changes, it will available at GNUJobs.com.
LG index which has many articles on networking and firewalls. You may also want to look at Linux.org to find documentation on how to setup a firewall.

Introduction

The Ricochet modems are wireless modems that let you connect your computer to the internet through an ISP provider that is hooked up to the wireless network. It is only available in certain areas.

None of the ISPs support Linux. They officially only support crappy horrible operating systems are not good for a technical person or a real programmer. Naturally, Linux, FreeBSD, and other good quality operating systems are ignored. It makes sense from profit point of view. Call the ISPs and let me know you want them to support real operating systems.

The modems will connect at 80 Kbps with a serial port and 128 Kbps for a USB connection. I only use the serial port connection, for now, and it seems faster and more stable compared to a normal dial-up over the phone. Sometimes it crawls, but overall, I am very happy with the modem.

Getting Ricochet

None of the ISPs support Linux. Wireless Web Connect seems to be more liberal, so I choose them. All the other service providers seemed to have staff that had no clue what Linux was and they had a big corporate feel, which I usually try to avoid. I bought my modem through the service provider for around $100, which apparently was a special price, but I have noticed that special prices tend to become the normal prices over time in the ISP market.

Installing the Ricochet modem

Installing the modem was really easy after I found the right webpage. Metricom modems support in Linux.

It was this simple on a RedHat 6.2 system (when am I going to switch to Debian for good?),

Start the control panel with the command "control-panel" in Xwindows.
Click on the Network Configurator.
Click on the "Interfaces" button.
Click "Add".
Choose the PPP option and continue.
Type in "3333" for the phone number, and the username and password. Select the PAP option.
After you have added the ppp interface, click on the interface, click on the Edit button and type in "noipdefault" where it says "PPP Options". Then click on "Done".
Save and quit the control-panel.

Now you need to follow the specific instructions the above article talks about. You need to modify /etc/resolv.conf for the DNS and edit /etc/ppp/pap-secrets as described in the article.

Overall, it was simple once I knew what to do.

If you have tried to figure out how to setup the modem, and you cannot, and you have read this article and the other article mentioned above, then send email to GNUJobs.com at articles@gnujobs.com and perhaps I can point you in the right direction. If you attend the SVLUG meetings in the Bay Area, bring your laptop and send me email when you are attending the next meeting, and I can help out.

Setting up a firewall for your network

I have a desktop computer and a laptop. I don't like using the touchpad on my laptop, and since I have to use the serial port for my external mouse, I can't use the Ricochet modem (unless I use the touchpad). Thus, I use my desktop computer as a firewall. I connect the desktop computer and laptop to a 100 mbit hub. Then I connect the Ricochet modem to the desktop computer.

The desktop becomes my firewall. I don't have any services running on it except for ssh. All the other ports are closed. Please use the program nmap to scan your computers to find out which ports are open. I would also disable the root account from logging in with ssh.

If you wish to know how to setup a firewall, I 9have written many old articles for the Linux Gazette about networking and firewalls. There are lots of resources out there. Try linux.org also with their HOWTOS.

Why do this stuff?

As an independent consultant, having the ability to go anywhere and be connected is nice. Not having to pay startup costs every time you want to get a 2nd phone line in an apartment is nice. I really loathe the local phone companies for hitting businesses with high phone bills. The wireless modem ends up paying for itself after you combine a phone bill and an ISP bill.

It isn't super fast, but for my needs it is just fine. I am still going to get a DSL hookup. This will provide me with two alternate ways of connecting to the internet should one route die for a day. That can be very bad for an independent consultant, so two routes are a must.

I leave the modem on all day and the firewall on all day. It is nice that it doesn't tie up a phone line and it is also nice that I don't have wires all over the place. When I had to move to a different room because the guy who was assembling my furniture kicked me out of my office, it was nice that I could take the laptop with the Ricochet modem to another room.

Conclusion

The Ricochet modem is good for connecting to the internet and is a must for a traveling independent consultant. I don't work for or get paid by Ricochet or the service providers for Ricochet, so my opinion isn't skewed. It is easy to setup, with just a few modifications. If you cannot afford it as a business expense, don't do it and get a DSL line instead for personal use because it is not going to be as fast as DSL and it can be more expensive than DSL. There are bonuses and negatives to getting the Ricochet modem. If we ever get to the point where the speed gets upto 500 Kbps, then DSL has no real advantage for me (except in the Bay Area getting a fixed ip address with DSL seems to be $30 more a month which is a lot cheaper than what I paid for to get a fixed ip address using Cable Modems in Columbus, Ohio).

Mark works as an independent consultant donating time to causes like GNUJobs.com, writing articles, and writing free software.

"Linux Gazette...making Linux just a little more fun!"