Wifi Connectivity

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Overview

XO laptops were intentionally designed for children in developing nations, where it is faster and less expensive to introduce wireless connections, rather than a traditional telecom infrastructure. The XO Laptop is primarily designed to network with other XO Laptops using a mesh network, but the XO is also wifi capable.

At the moment, an XO laptop cannot be on both the Internet and on the mesh network at the same time with a default laptop configuration. This ability will hopefully be re-enabled by default in the future; until then, School Servers can serve as Mesh Portals, and further details can be found on the Mesh Network Details page.

Getting Started

• you must have a Wireless Access Point (WAP) nearby
• verify the network name (SSID) and its password, if it has one
• carefully follow the Gettting Started instructions

Special Considerations

Wireless Access Point Setup

The OLPC Support Team has been gathering notes and configuration tips for various Wireless Access Point (WAP) connectivity. We are actively working to resolve minor compatibility issues with various Wireless Access points.

Some key setup considerations for your Wireless Access Point are:

• A single channel should be selected, not "Automatic"
• Preferred Channels are 1, 6, and 11
• The wireless network mode should be "Mixed" or "Wireless-G", not "Disabled" or "Other"
• If Wireless MAC Filtering is enabled, the MAC address for the XO must be entered
• The latest Firmware should loaded on your access point
• Make sure that there are only alphanumeric characters and no spaces in your WAP's SSID

SSID Network Name

When in the Neighborhood View, your Wifi SSID should be visible when you hover over the hotspot dot.

If you have a hidden SSID, your hotspot dot will not be visible. The network can be manually added using the iwconfig command through the Terminal Activity:

su -l
/sbin/iwconfig eth0 mode managed essid <myhiddennetwork>
/sbin/dhclient eth0
exit

• su -l creates a root process;
• iwconfig connects to your hidden network (of course, substitute the name of your access point for the <myhiddennetwork> in the above example);
• dhclient will ask for an IP address from the access point.

Channel

With 802.11b or 802.11g, use channel 1, 6 or 11 in the US or Canada. Use of any other channels will degrade your own wireless signal and that of others.

Similarly, the mesh networking between XO laptops is restricted to work only on channels 1, 6 or 11.

Security

What is the difference between a key and a passphrase?

When you try to connect to a secured (encrypted) network your XO has to send an encryption key to the access point. This key is derived from the passphrase you chose when you configured your access point (and also from the ESSID, if you are using WPA).

So, the passphase is the long password that is relatively easy to remember while the key looks like a random sequence of characters. The lenght of the key varies depending on the type of security and it is usually represented in its Hex form, meaning that it will be formed by a sequence of digits and letters from A to F.

Here is one example, for WEP:

• Key length: 128 bits
• PassPhrase: MyPassPhrase
• Resuting Hex Key (26 characters long): 381E966F1EAE4140F83D30C201
• Converted using: http://www.corecoding.com/utilities/wep2hex.php

Here is another example, for WPA-PSK:

• Key length: 256 bits
• PassPhrase: MyPassPhrase
• ESSID: MyEssid
• Resulting key (64 characters long): c3044f3fbd077e236d12f0b1f9d7761e0e6de266783d843d76edf1da3131bff6
• Converted using: http://www.xs4all.nl/~rjoris/wpapsk.html

WEP Security

WEP Security is built in to the XO.

WPA Security

WPA security was not initially supported on XO laptops. If you are a knowledgeable Linux user, you can find instructions here to access the Internet with WPA security, by manually setting up WPA. It may be best for less experienced users to wait for the next stable XO software release, which should be available by the end of Janurary 2008. If you absolutely need WPA now, you can get it by performing an Upgrade to version 653, but in the process you may lose all data on your laptop.

Can I calculate a WPA key using an XO?

Note that WPA is not currently supported (as of build 650, Dec. 2007), but yes, you can.

1. Start the "Terminal" activity from the Frame; instructions can be found here. You may have to scroll the icons along the bottom of the Frame to the right (by clicking on the button at the right of the Activities taskbar) to find the icon; it is labeled "Terminal".

2. Type the following, substituting the values for ssid and passphrase (and then press the "Enter" key):

/usr/sbin/wpa_passphrase <ssid> <passphrase>

3. The key will be displayed in the line starting with "psk=".

If you plan to use the same WPA key frequently, there is a script available at WPA Manual Setting with discussion here and here

MAC Filtering

Wireless MAC Filtering is a security measure that restricts access to the WAP by MAC Address. Every computer or other peripheral has a unique HEX address assigned at the time of manufacture.

The MAC address for the XO is displayed using the Linux command ifconfig.

Specific WAP Notes

A complete matrix of Wireless Access Point Compatibility is being updated by the support community.

Apple Airport

There are two kinds of Apple Access points: WEP and WPA. If you have WEP:

1. Go to: http://www.corecoding.com/utilities/wep2hex.php and convert your password into a hex phrase.
2. Click on the Access Point in the neighborhood view.
3. Choose Hex input for the key; and choose "shared" key instead of "open".
4. Enter your hex phrase.
5. You should be able to associate to and authenticate a connection to an Apple Access point.

If you have WPA, you should note that WPA is not working from the User Interface in build 650. You should upgrade to build 653.

Verizon FIOS

The XO cannot see the wireless access point reliably and cannot connect to ActionTec M1424WR unless the router must be set up to use one channel exclusively (1-11) rather than rotate the channel selection

From a computer other than your XO:

1. Go to your Browser, and type in 192.168.1.1
2. Screen will open, and you will need to insert "User Name" and "Password." The Default response would be admin / password
3. New screen will open. Along the top you will spot "Wireless Settings." Select that category.
4. Along the left side you will see a column. Choose 'Basic Security Settings."
5. Look for Section.....3. Channel: ______________ If it says "Automatic." it is rotating through eleven channels. Choose just one channel, preferably 1, 6, or 11.
6. Click the "Apply" button.

Belkin Pre-N

Some access points that have reported intermittent problems with XOs:

• BelkinPreN - XO Connects but all other systems disconnect

If you have one of these access points, please contact technical support if none of the basic setup fixes solves your connection problem.

Linksys WRT54GX2

Some access points that have reported intermittent problems with XOs:

• Linksys WRT54GX2 - XO Connects but cannot access internet

If you have one of these access points, please contact technical support if none of the basic setup fixes solves your connection problem.

XO Setup

network.cfg

The network.cfg file contains information about the current network configuration from session to session.

If you want to remove any "memory" of connecting to a particular access point or if you change the configuration of your Access Point (such as adding or removing security features), then you will need to remove this file in order to get your XO to connect to the Access Point.

• Launch the Terminal Activity to delete the network manager config file by typing:

rm /home/olpc/.sugar/default/nm/networks.cfg    (press "Enter")

Restart your XO laptop, or restart Sugar by pressing the Ctrl+Alt+Erase keys at the same time; your laptop will NOT automatically try to connect to the "known" access point.

Proxy Settings

The initial software build on the Give1Get1 shipped in December 2007 (Build 650) does not support a user interface to change the web browser by proxy settings. There is an outstanding bug (#2910) on this.

Troubleshooting Guide

The Wifi Troubleshooting Guide provides a step by step checklist to review prior to contacting Technical Support.

Sharing User Experiences

The wiki page Wifi Connectivity summarizes experience connecting OLPC XOs to WiFi. But, it takes some effort to create such a summary; moreover, there is necessarily a delay, since it may be premature to correct an entry for a particular wireless router based on 1 learning, when there are 100 preexisting learnings; finally, such summaries are always subject to a degree of thrashing as issues are worked out.

It is therefore often good to record raw user experience first, and summarize later.

The page Sharing User Experiences with OLPC XO Wifi Connectivity has therefore been created for such raw records.

When trends become obvious we of course invite peopl to summarize as best they can. Nobody wants to have to read through dozens of raw user records to figure out if there is a problem with a particular router; but, conversely, it is equally bad to have a summary say "There are no problems with a router", when people have encountered such problems, but have just not yet figured out exactly where the blame lies.