From TIER

1 Getting Started

1.1 Resources

TIER typically ships equipment pre-assembled and loaded with the latest version of TierConf, and other software that we use. This manual only covers configuration of IP addresses, radio parameters and other tasks that are typically done on the ground. This section provides references to other documents which describe the process of designing, building and configuring networks from scratch.

Assembly of a 6ft parabolic dish antenna

• For network design, please see our Wireless Network Design Guide
• For assembly instructions:
  1. Routerboard assembly
  2. WRAP board assembly
• For instructions on how to install Tier Linux, see our guide to Writing Tier Linux to a CF Card (you will need a CF card reader, a USB cable and screwdrivers)
• For a more complete guide to the TierConf web based router configuration tool, please see TierConf Manual
• Our 24dbi antennas are sometimes a bit tricky to get put together because of manufacturing defects. If you are having trouble, please see our Antenna Assembly Guide
• For more details on how to characterize links, see our Link Characterization Guide
• This guide is part of our wireless training curriculum

1.2 Spectrum Licensing

Spectrum licensing is different in every country. Most of our radios use the 2.4Ghz ISM band spectrum or the 5.8Ghz spectrum, but we have some equipment which uses other frequencies. Please ensure that your radios are not interfering with licensed bands.

Since 2.4Ghz is unlicenced in most countries, networks in urban areas often experience interference with other radios, particularly WiFi radios, but also proprietary data networking radios, cordless phones, and even microwave ovens. If the 2.4Ghz spectrum is too noisy for good performance, you can try the 5.8Ghz and 5.2Ghz spectrums with most of our radios, but you will need a license for those bands in many countries. Also 5.8Ghz requires different antennas and normally has shorter range.

We are currently developing frequency adapters to allow WiFi radios to operate at different, licencsed frequencies. Lower frequencies also have better propagation characteristics for long distance wireless networking, so check back if you are interested.

2 Configuration

2.1 Getting Started

This section describes how to test the equipment on the ground and configure it to operate within your network.

2.1.1 Powering up the board for the first time

Warning: Follow these intructions carefully to avoid accidentally frying your board. Please see the warnings in the Power-over etherenet Installation section.

You will need:

• WRAP or Routerboard single board computer
• POE injector, with AC/DC converter
• plug adapter for AC/DC converter if necessary
• 1 straight (e.g. not crossover) and one crossover ethernet cable
• computer with ethernet port and web browser
• cable tester

2.1.1.1 Powering up a WRAP board

Warning: Do not use a POE injector intended for a routerboard or any other device with a WRAP board. The WRAP boards use a non-standard 12V or 18V power supply whereas Routerboards and most other POE devices use 48V. A 48V power supply will definitely fry your WRAP board (we've done it).

A WRAP board with the POE inject properly attached to the board and computer

1. This step is very important! Test both cables and make sure that they are properly crimped on all wires
   • Note: Ethernet only uses four of the eight wires in a CAT5 cable, so just because a cable works with your computer does not mean it is properly crimped. Use a cable tester, or risk frying your board.
2. 

   

   A POE injector correctly connected.
   Plug the POE port marked "P+DATA OUT" into the external input of the WRAP board enclosure using a straight cable. If the wrap board is not in the enclosure then make sure you plug the cable into the rightmost ethernet port on the board. Use the port on righthand side of the injector when the green light is on the top of the injector and the ports are facing towards you.
   • Note: If your POE injector doesn't look like this, make sure you are not using one intended for a Routerboard (it it is for the Routerboard, do not use it!), then look for something that says "Power" or "P OUT" or something to that effect. That one goes to the WRAP board.
3. Make sure that the AC/DC adapter outputs 12 volts. Don't use an AC adapter that was not supplied with the POE injector unless you are certain that it outputs 12V and can output sufficient power to the board (around 10W or 1A).
4. Plug in the AC/DC adapter into the wall and then into the POE injector. You may need a plug adapter as well. Most of our AC/DC adapters can take 110V-240V, but make sure to read the label to make sure. If it does not, then you will also need an inverter to convert the voltage from 240V to 110V. These can usually be purchased at electrical supply stores.
5. Watch for a the lights on the right hand side to flicker and then remain constant. WRAP boards do not beep when they start up.

2.1.1.2 Powering up a Router board

Warning: Do not use a POE injector intended for a WRAP board, or any other device with a Routerboard. The WRAP boards use a non-standard 12V power supply whereas Routerboards and most (but not all) other POE devices use 48V. A 12V power supply will probably fry your Routerboard board, since under-powering IC devices often destroys them (we've never actually done it though).

A RouterBoard with the POE injector properly attached to the board and computer

1. This step is very important! Test both cables and make sure that they are properly crimped on all wires
   • Note: Ethernet only uses four of the eight wires in a CAT5 cable, so just because a cable works with your computer does not mean it is properly crimped. Use a cable tester, or risk frying your board.
2. 

   

   A RouterBoard POE injector properly connected
   Plug the POE port marked "P+DATA OUT" check text here into the external input of the Routerboard enclosure. If the Routerboard is not in the encosure then make sure you plug the cable into the rightmost make sure rightmost is correct ethernet port on the board. This is the port on the righthand side of the injector when the green light is on the top of the injector and the ports are facing towards you. check this description carefully
   • Note: If your POE injector doesn't look like this, then first make sure it is not the one intended to be used with a WRAP board (if it is for a WRAP board, do not use it). If it is indeed intended for the Routerboard (eg. it is a 48V POE injector) look for something that says "Power" or "P OUT" or something to that effect. That one goes to the WRAP board.
3. Make sure that the AC/DC adapter outputs 12 volts. Don't use an AC adapter that was not supplied with the POE injector unless you are certain that it outputs 12V and can output sufficient power to the board (around 10W or 1A).
4. Plug in the AC/DC adapter into the wall and then into the POE injector. You may need a plug adapter as well. Most of our AC/DC adapters can take 110V-240V, but make sure to read the label to make sure. If it does not, then you will also need an inverter to convert the voltage from 240V to 110V. These can usually be purchased at electrical supply stores.
5. Listen for a beep shortly after you plug in the power. Routerboards beep once when they boot.

2.2 Connecting to the SBC

Once you have sucessfully powered up the board, you can configure it to operate on your network. The preferred method for configuration is via TierConf, a Web-based GUI tool for configuring the router. If you are having trouble connecting to the ethernet port of the router, you can alternatively use the console on the serial port to log in and configure the router so that you can connect using the web browser.

2.2.1 Etherenet

By default, TIER routers ship with eth0 and wlan0 configured as follows:

• eth0: With DHCP client that tries to acquire an IP address from it's subnet.
• eth1: 10.0.99.1/24 : With DHCP server that gives out IP addresses on between 10.0.99.100 to 10.0.99.200

Often, however, we configure the wireless interfaces in a manner similar to which they will be deployed. In that case we will send you spreadsheet with each machines configuration. You will need to use a crossover cable unless the ethernet port on your computer is auto-sensing.

2.2.2 RS232 Serial

Connection to a RouterBoard via serial cable and ethernet

Choose any file name for the connection and click "OK"

Choose the com port connected to the router

Set the serial port to to 19200 baud, 8N1

If you are having trouble connecting to any of the interfaces on your routers, the first thing to try is to connect to the serial interface. You will need a null-modem cable and a computer with a RS232 serial interface. We normally ship our equipment with a null modem cable and a USB-to-RS232 converter.

To connect to the console on the RS232 serial interface, connect the null modem cable to the computer and the router. If you laptop runs windows, start up hyperterminal. Choose "File->New connection", and enter any name and icon. On the next screen, choose the serial port connected to the router under the "Connect Using:". If you don't know which serial port is connected to the serial port, you will have to try the different ones until you figure it out.

On the next screen choose 19200 note: confirm that this is the right setting! bits per second, 8 data bits, no parity, one stop bit and hardware flow control.

If the router is still booting you will see the various text describing the linux boot process. Eventually, you should see a "Login: " prompt. You may need to press return a few times to get the prompt. Type "root" for the login (lower case). The default password is "soekris." Change the password immediately after login by typing. The change password program will not echo back when you change the password.

tier-router # passwd
Enter new password:
Password changed
tier-router #

Once you have changed the password type

tier-router # less /etc/network/interfaces

and find the eth0 interface in definition. You can then configure your laptop on the same subnet as this address and user the TIERconf program to do the rest of the router configuration.

2.3 Configuring the router

The TIERconf front page

2.3.1 General Setup

This page can be used to edit basic information like hostname and administrative password

The TIERconf web interface is mostly self explainatory for a network administrator, but we will walk through the steps to set up the basic network configuration.

Point your browser towards the IP address of the router if you are connected to the eth1 ethernet port. For example: http://10.0.99.1/

The default login is 'admin' and the default password is also 'admin'.

Once you have logged in you will see a front page screen with some basic system information, and a navigation bar on the left hand side. This navigation bar will be used to select the pages that you will use to edit the configuration of the router. First, click on the General System link. Edit the host name, domain name, DNS servers, and password for the admin acount. You can also select a NTP server and parameters if you want. Click Save.

2.3.2 Setting up the interfaces

Edit the IP address with this page

Next select eth0. Set the IP address, subnet mask and default gateway (if applicable). Click Save. Do the same for other ethernet interfaces if you want.

This prompt appears at the top of the screen when you have edited a network interface

You will see a prompt at the top of the screen after you click save informing you that you must restart the network services for the changes to take effect. Wait until you have changed all of the interfaces to the settings you want before you restart the network services.

Now select ath0 or wlan0 (ath denotes atheros chipset based cards and wlan denots prism and other chipsets). The Auto field can be left as Yes for any atheros based cards, including all of the routers which were sent to Guinea Bissau.

Set the IP address, subnet mask and gateway. Set the protocol to 802.11b, set mode to master or managed ( master means that the router will act as an access point, and managed means that it will act like a client to an access point), depending on the configuration of your network. Set the SSID (this must be the same for the master and managed nodes), channel (1,6, and 11 do not interfere with one another, so we recommend that you select one of these, and again they must be the same), and leave the bitrate on auto. Click Save.

Do this for all of the wireless interfaces, and then click on the Restart network services link at the top of the page.

This confirmation page appears before the network services actually restart, in case you forgot to write down the interface configurations

You will get a confirmation page which advises you to make sure you know the IP addresses of the interfaces before you restart. Otherwise, you will need to connect via serial port to figure out the IP address (See above), which is a pain in the neck. Once you click Yes, the networking services will restart. If you have changed the IP address of the interface to which you are connected, you will need to point to the new IP address. You may also need to reconfigure the interface of the computer which is connecting to the router to be on the same subnet as the router again as well.

2.3.3 Setting up routing

Control for editing static routes

TIERconf supports both static and dynamic routes. You should note, however, that using both simultaneously can lead to routing loops which are difficult to debug. We recommend using static routes unless you are familiar with dynamic routing.

This screen is used to add or edit a static route

Click on the Static link in the navbar. By default, there are no static routes configured. Click on the (+) symbol on the right hand side of the screen. You will be promted to enter the destination network (and netmask, denoted as the number of bits set to one from the left hand side), and the gateway used to reach that network. Click Save. Repeat until the router is configured.

2.3.4 Storing the configuration

TIERconf stores its configurations to both the standard system files and also a single, portable XML file. This XML file can be used to replicate the configuration of a machine across several routers. It can, however, become out of sync with the system configuration files such as /etc/networking/interfaces if you edit those files by hand. In that case, you must click on the Read/Save Configs link and read in the relevant files. You can get more information about config files in the TierConf Manual.

2.3.5 Staging

You should do as much of the configuration, set up, building and testing as possible in a controlled environment where you have access to tools, internet access, manuals, computers etc. Once you get into the field, minor problems can mean lost days of work if the deployment is in a remote location. As such, set all of the routers up exactly as they will be deployed in the field, including configuration, cables, antennas etc.

With that said, a word of caution is in order. High gain antennas direct microwave radiation in a very high powered focused beam that is powerful enough to cause health problems. Avoid pointing 24dbi parabolic grids at yourself, particularly at very close range, and particularly at your head or genitals. If you every feel heat from an antenna, move away immediately.

Just so you understand the danger that a 24dbi antenna presents, lets look at a typical example:

The cards we ship with most routers output microwave radiation at 400mw. 24dbi is equivalent to a 251x increase in power, so thats like standing near a 100W microwave oven with no shielding, directed at you genitals, eyes or brain. Do you really want that? If you also use a 1W amplifier, then thats 251W. Many microwave ovens are sold with similar power ratings. Please be careful.

In any event, when we stage networks, we typically use the dipoles from the antennas we intend to use, but unconnected to the parabolic dishes. This avoids any risk of harmful exposure. We configure the entire network, and make sure that we can connect from end to end, ping and route to each machine, and run any applications over the links that we intend to run. We usually discover some configuration errors in the process. These are often subtle, and involve the interaction of several machines, so it is very important to debug these problems when you access to all of the machines, rather than when you have to drive back and forth between machines in the field.

3 Installation

This chapter discusses the steps and precautions to take during installation of TIER wireless routers, including safety procedures, pre-installation assembly, antenna installation, router installation, Power-over-Ethernet installation and lightening protection installation.

3.1 Safety Procedures

Melissa on a mast at the University of Ghana, Legon, wearing a hard hat and two lanyards. The yellow landyard is to catch her in case of a fall, and the blue lanyard can be adjusted to position her on the mast.

Disclaimer: We are not licensed or trained to install wireless equipment, climb towers or otherwise advise you on how to safely and correcly set up this, or other wireless equipment. We are not liable for injury to you or damage to your equipment. Please use this as a installation guide on how to set up the TIER wireless equipment, but do double check its accuracy and use your common sense. We can not guarantee against mistakes, omissions or other errors which might result in financial or bodily harm to you. In other words, we are not liable, licenced or competent.

Basic safety precautions which we strongly recommend that you follow for tower installations:

• Everybody who is climbing the tower/mast or on the ground area should wear a hard hat. The velocity of a dropped nut from 40m is enough to kill you.
• Inspect your safety equipment before every climb, particularly your lanyards: lanyards rubbing against metal masts can easily fray and break. Wear two laynards when possible: one to position you on the mast, and another loose lanyard to catch yourself in the event of a fall. Always clip in the lanyards, even when working on work platforms on towers/masts.
• If you hear thunder, even distant thunder, get on the ground and away from the mast immediately. Lightning storms cover a wide area, and can strike far away from previous strikes.
• If the mast is wet from a rain or dew, do not climb. Wet metal is extremely slippery. If the mast is always wet, use extreme caution.
• As mentioned above (See Staging), a router with a typical configuration of 400mW radios and 24dbi antennas outputs a focused beam equivalent to approximately 100W of (isotropic) power. You don't want that pointing at your genitals, eyes or brain. Momentary exposure is probably not a big deal (but certainly could be), but any prolonged exposure is likely to cause infertility, cateracts, seizures or other problems you might expect from cooking your genitals, eyes or brain. This is doubly important (actually 2.5 times as important, to be precise) when using a 1W amplifier, since that would result in a microwave beam similar to standing next to an unshielded 251W microwave oven. If you ever feel heat from an antenna, move away and/or turn it off!!!

If you think we are being overly cautious think again. Injury and death to mast climbers is not uncommon in the United States, but is usually the result of failure to follow safety procedures. Please be very careful: it would be very upsetting to find out that someone died installing our equipment!

3.2 Pre-installation

Installation of the standard TIER equipment does not typically require a pully. The radio, antennas and cables can all be carried up by the engineers. Larger dish antennas will require a pully. Installation of larger dishes is not covered in this manual.

Plan the position of each antenna before climbing, including vertical distance from other antennas on the mast. Even if the antennas are operating at a different frequency, they can sometimes interfere if they are on neigboring frequencies and the antennas are extremely close. Make sure you bring suffient RF cable up the mast.

Assemble the antennas before climbing if possible. The two piece 24dbi antennas that we typically use are sligtly difficult to assemble, and it is easy to accidentally drop a nut or bolt.

On your first climb, tie the Cat 5 onto your harness and pull it up with you. For long climbs, someone on the ground may need to pay out the cable from the spool to avoid kinking the cable. If you are climbing inside of a cage, you may need to hold the cable outside of the cage as you climb.

Warning: kinking the cat 5 cable can ruin it or degrade performance. Please use caution

3.2.1 Equipment taken up tower

• Antennas : Assembled antennas, RF cables for each antenna and mast adapters
• Wireless router: Assembled, sealed and configured router and mast adapters
• Lightning equipment: Surge arrestors (for each antenna), grounding wire, grounding clamp
• Ethernet : CAT5 cable, cable ties, CAT5 connectors
• Sealing : Rubberizing sealant tape, UV protective electrical tape

3.2.2 Tools taken up tower

• Shifting spanners (adjustable wrenches) for mast adapters
• Screw driver to open enclosure, to adjust grounding wire on surge arrestors
• Ethernet: CAT5 crimping tool, CAT5 cable stripper, one end of the cable tester (leave the other end on the ground)
• Folding knife or wire cutters to cut cable ties
• Safety tools: hard hat, headlamp

3.2.3 Equipment on ground

• POE Injector

3.2.4 Tools on ground

• Hard hat
• Wireless enabled laptop for testing
• Other end of cable tester

3.3 Router Installation

Attach the surge arrestor directly to the router enclosure, and tape it with both rubberizing tape and UV protective tape, to protect the seal from moisture, and to protect the rubberizing tape from UV exposure. Failure to do both will result in degraded performance

Once you have climbed to a position in which the router will be installed, you can follow the following procedures to install fix the router to the mast.

1. Attach assembled wireless router to mast with lanyard
2. Mount the router to the mast in a convenient spot : make sure that the RF cable reaches from the correct interface to each antenna
3. Attach lightenening surge arrestors to each interface of the router
4. Wrap each RF junction with rubberizing to seal any moisture out of the junction
5. Wrap UV protective electrical tape to prevent decomposition of the rubberizing tape

3.4 Antenna Installation

Warning: Kinking the RF cables will almost certainly ruin them.

Once the router has been mounted on the mast, mount the assembled antennas on to the mast such that you can reach the antenna connectors from the router using available RF cables.

1. Attach antenna to mast with lanyard
2. Mount mast adapter to mast
3. Mount the antenna to mast adapter : leave firm but loose enough to adjust orientation
4. Attach RF cable to antenna
5. Seal the RF junctions with rubberizing tape and UV protected electrical tape

3.5 Lightening Protection Installation

Attach the grounding wire to the ground header, and then squeeze the ground header with pliers to ensure that the grounding wire does not move. Note that you should use 3-gauge copper wire, as opposed to steel wire as we do in this image, if possible.

1. Make sure that you have already attached the surge arrestor directly to the enclosure of the router, and wraped the junctions with rubberizing tap and electrical tape (failure to do so will result in degraded performance over time)
2. Cut sufficient grounding wire to reach the grounding clamp from the radio interface, for each antenna
3. Attach the grounding clamp to the mast
4. Attach the grounding wires to the grounding clamp and the surge arrestors
5. Wrap the junction between the surge arrestor and the grounding wire with rubberizing tape and electrical tape

3.6 Power-over-ethernet Installation

Warning: You can easily fry your radio by incorrectly crimping the RJ-45 connector to the CAT5 cable (we have done it more than once)! Do not connect the cable until you have tested it with a cable tester.

Warning: You can easily fry your laptop/router/hub/etc. by plugging it into the wrong port of the PoE injector. Be doubly certain that the power is not being injected into the wrong device!

Warning: Kinking the Cat 5 cable can ruin it or degrade performance. Please use caution, and have someone on the ground pay out the cable.

The POE injectors we use are not waterproof: they must be housed in a water-tight power enclosure or indoors and not on the tower itself. Please use the following procedure to install the POE equipment:

1. Run the CAT5 cable to the power source leaving a couple of meters of slack to allow for changes in the plan on both ends. Have someone on the ground pay out the cable to avoid kinking.
2. do not plug it in to the PoE injector yet!
3. Run the CAT5 cable to the router on the mast and cut it, again leaving a few meters of slack.
4. Push the CAT5 cable through the outer portion of the RJ45 waterproof housing and crimp the end, using a straight cable configuration (not cross-over).
5. Attach the cable tester to either end and test and recrimp until the tests succeed
6. Insert the crimped cable end into the enclosure and plug it to the board
7. Tighten the RJ45 connector and seal with rubberizing tape and electrical tape.
8. Use cable ties to secure the CAT5 cable to the mast as needed

3.7 Initial Testing

Use the following procedure to do preliminary testing of the installation:

1. At the power source, plug in the POE injector to the AC power source.
2. Attach the PoE injector power output port to the cable leading to the radio. This will power up the radio. At the risk of sounding too repetitious, please make sure you have tested the cable before plugging it in.
3. Attach the LAN side port of the PoE injector to a hub with a straight cable, or directly to a computer with a cross-over cable.
4. Configure a computer connected to the network with an IP address on the same network as the ethernet 0 interface of the router. By default, eth0 is set to an address in the range 10.0.1.11/24 through 10.0.1.14/24 in Guinea Bissau.
5. Ping the address of the router until you receive a response. This can take a minute or more after the router is powered up : if you don't get a response, go to the troubleshooting section
6. Point a web browser at the address of the router, and confirm the configuration is correct.

3.8 Alignment

Right now, the best tool we have for alignment is to monitor signal strength using the iwconfig command.

While performing alignment, log in to the router using ssh. Now suppose that you are attempting to align the antenna attached to ath0.

3.8.1 Step 1: Configure routers in Master/Managed mode

Configure ath0 on Router X as Master

Configure ath0 on Router Y as Managed

When the link is configured in master/managed mode, one router is running in Master mode and the other router in Managed mode. The managed side of the link will be able to test the received signal strength (RSSI), because the RSSI is determined using the periodic beacons that the Master node sends. Therefore, in order to do alignment, the installation engineers first set one router to Master mode, the other in Managed mode, then perform alignment of the antennas on both sides while looking at the signal strength on the Managed node.

Example: Use the web-based GUI to configure 30km link from Router X to Router Y

Router X: Master mode is on interface ath0 (10.1.100.1) on channel 6 and bitrate 11Mbps, antenna 1
Router Y: Managed mode is on interface ath0 (10.1.100.2), antenna 1

3.8.2 Step 2: Alignment for maximum RSSI

To see the RSSI for ath0, type

# watch -n 1 iwconfig ath0

This command repeats the iwconfig command every 1 second. The RSSI parameter is the signal strength, or you can look at the link quality parameter, which is the Signal to Noise Ratio (SNR).

So a typical alignment session might appear as follows (Router X indicates that an action is executed on router X, and similarly for Router Y):

Router X: Configured in Master mode  
Router Y: Configured in Managed mode
root@router-y # watch -n 1 iwconfig ath0

The engineer at Router Y then aligns the antenna attached to ath0 to maximize the RSSI or link quality. Next:

Router X: Configured in Managed mode 
Router Y: Configured in Master mode
root@router-x # watch -n 1 iwconfig ath0

The engineer at Router X then aligns the antenna attached to ath0 to maximize the RSSI or link quality.

4 Monitoring

An example crontab configuration page

An example crontab entry

Phone home allows the TIER research group to monitor the status of the machines we have in the field, even for networks that are behind a firewall. It functions by periodically initiating an outgoing connection from the router to a machine at UC Berkeley. The "Phone Home" script tells us the status of the machine. Another script, the SSH tunnel script, creates an SSH tunnel which allows us to connect from Berkeley to the machine and perform remote maintenance. This tunnel can only be used by TIER researchers who have been granted access.

These two functions are encapsulated in a script called /usr/local/bin/tunnel-wrapper, which is periodically run from cron. This is pre-configured in most machines, but will only work if the network permits direct connections to the internet. In the event that the network uses a HTTP proxy server, or if you want to change other parameters of Phone Home, you can do so as follows.

The crontab, the configuration file which schedules periodically running jobs, can be edited with the TIERconf user interface. The last item in the "Advanced" menu on the sidebar is titled "crontab". When you select the "crontab" entry, you will see all of the jobs which will be periodically run on the machine (see Figure). If you click on the "e" next to an entry you can edit the times that it runs, as well as the command that runs (see Figure).

4.1 Connecting from a network with direct internet access

For a network with direct internet access (e.g. a web browser does not require a proxy server to connect to the internet), the following entry should work correctly

/usr/local/bin/tunnel-wrapper  -z /rw/tmp/ -t [TUNNEL_TIME] > /rw/tmp/cron.httunnel.out 2>&1

Replace [TUNNEL_TIME] with the number of seconds that you want the tunnel to remain open. We typically set this parameter to 10000 seconds. Typically, this command runs once per day.

4.2 Connecting through a HTTP proxy server

An example HTTP tunnel configuration page

An example HTTP tunnel entry

Things are slightly more complicated if the only means of connecting to the internet is through a proxy server. We must add a HTTP tunnel, and add two more parameters to the crontab entry for tunnel-wrapper

First, add the HTTP tunnel entry. In the left sidebar menu, under "Tunneling," there is an entry for HTTP Tunnels. When you click on this, you will see a list of HTTP tunnels already created, and a button in the lower right hand corner to add a new tunnel. If there is already a tunnel configured, then you can edit it or add a new one as you see fit. The only two parameters that you will need to edit are the local port, which we typically set to 10000 (but which you might want to change for some reason, e.g. if you have multiple tunnels), and more importantly, the HTTP proxy server's IP address. Edit the "HTTP Proxy URL" (in the form "http://IP-ADDRESS:PORT" Save your changes and click the "Restart service" button that is presented once you have clicked "Save."

Now you can edit the crontab entry for tunnel-wrapper. In addition to the [TUNNEL_TIME] parameter (see #Connecting from a network with direct internet access above), we must add the -k [PROXY_IP]-k [PROXY_PORT] options. Replace [PROXY_IP] with the IP address of the proxy server (as you would in a web browser, and similarly with [PROXY_PORT]. The whole command will follow this template:

/usr/local/bin/tunnel-wrapper -d localhost -p 10000  -z /rw/tmp/ -t [TUNNEL_TIME]-j [PROXY_IP]
-k [PROXY_PORT] > /rw/tmp/cron.httunnel.out 2>&1

Although we have split this over multiple lines for formatting reasons, this must be all on the same line. If the port you have chose for the HTTP tunnel above is different from 10000, then you must also change the -p 10000 to reflect whatever port you chose.

4.3 Cricket, Nagios, Google Maps based

5 Troubleshooting

5.1 Possible Situations

• Link not working
• Board does not boot
• TODO

5.2 How to locate and fix problems

Once you have rough idea of where the proble might be, you can try to isolate it and fix it.

5.2.1 Ethernet cabling

• An ethernet cable might be incorrectly crimped. If you see that the router board does not boot up, or you cannot ping it, then you should check the whether the cable is crimped correctly. Use a cable tester with one end on the ground.

5.2.2 Power supply

• Check for LED if present
• Use multimeter to check voltage
• Test with a different board

5.2.3 Hardware: Booting with Board, CF card

• To check if the board is booting, check the LEDs that show powered up status. The location of respective LEDs are specified for Routerboard and WRAP boards are specified in the assembly guide.
• The serial port (See the section " RS232 Serial" above) can always to be used to login to the board in case it the LEDs are showing up but it cannot be reached by the network. Depending on the output that you can see, you can check various components of the router.
  • No output at all: Board might not be working at all.
  • Shows BIOS prompt, performs memory checks etc and stops: Board is booting, but either CF is absent or corrupted or the OS is missing.
  • Shows LILO prompt and stops: CF card might be corrupted or OS might be missing.
  • Starts loading Linux and starts booting up: CF card is fine
  • See login prompt: OS is loading fine, but radio cards/ethernet interface still might not work. Also network configuration might be incorrect.
• If the board cannot be reached through the main eth0 ethernet connection that is connected to PoE, then the eth1 connection can be also be tried.

5.2.4 Hardware: Basic Checks

Once the user is logged in to the router either through the serial port or one of eth0/eth1, some basic checks can be performed.

• Check if all the partitions are mounted properly

# mount

• Check if ssh daemon is running

# ps -ef | grep ssh

• Check if the board is detecting all the network devices

# lspci
For the ethernet devices: 
For mini-PCI atheros cards: you should see
For PCMCIA atheros cards: you should see

5.2.5 Network configuration

Once the user is logged in to the router either through the serial port or one of eth0/eth1, some basic checks can be performed.

• Check 'ifconfig' for list of interfaces shown - the minimum list is 'lo, eth0, eth1'

# ifconfig -a

• Check 'iwconfig' to look at the list of all wireless interfaces.

# iwconfig

• Check if ssh daemon is running

You can also examine the file

/etc/networking/interfaces

This file has configuration options for each interface on the board. It is not recommended that you edit this file directly unless you have experience with this file, and you also understand how to keep the TIERConhttp://tier.cs.berkeley.edu/tierwiki/index.php?title=Wireless:InstallationGuide&action=edit Editf software in sync with the network files. Please see the TIERConf manual for more information (See the Resources section for details).

5.2.6 Radio Cards

Once it is verified that the radio cards are properly detected and the network configuration is correct.

• Check that the radio cards numbering is consistent with the antenna it is connected to and its network configuration. This is because if the board has multiple atheros cards, then the ordering for each board is described here. The card that is detected at ath0 is should be connected to the correct antenna.

5.2.7 Radio cabling

Once it is verified that the radio cards are properly detected network configuration

• Check that the pigtail on the radio card is connected to the correct antenna port. The cards have 2 antenna connectors - one main and one auxiliary. They are illustrated [[Wireless:Here | here].
• Bad connections - check the pigtail connection to the radio card, the bulkhead connection on the enclosure, the connection between the Male-Male cable and the dipole. Problem might be bad pigtail, bad cables, loose connections, water inside connectors.

5.2.8 Antenna setup

• Bad dipole - wrong frequency

5.2.9 Radio alignment and link

• Misalignment over time
• Polarization should be same on both sides

6 Training and Maintanence

• What extra equipment should be provided.
• What training is required.