7911G behind NAT

I can happily report that I have been able to run VoIP phones across a HSMM-MESH link.  I was surprised at how easy it was, once I was able to reproduce the results.

First off, I set the VoIP phones to static IP addresses.  I chose 172.27.0.51 since it was outside the range of  the router's DHCP (and I have been using the 172.27.0.5x space as VoIP experiments anyway).  

On the router that has the server on it, I forwarded UDP ports 5060 and 10000-20000 to the server by adding a line to the /etc/config/firewall file on the router.  This line will looks like:

forward:wifi:dport=5060,10000-20000 proto=udp dest=routerWiFiaddress:serverIPaddress

Replace the bolded fields with the appropriate IP addresses for your equipment; note there is a colon between the two IP addresses.

The router with just the phone attached, do the same thing but instead of the server IP address, put in the IP address of the phone:

forward:wifi:dport=5060,10000-20000 proto=udp dest=routerWiFiaddress:phoneIPaddress

For me, this was all that was needed.  The phones started working as if they were connected to the same LAN.

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Here is a photo of a demonstration I set up at the November 2012 CVARC club meeting:

The Trixbox server running on the laptop and one phone connected to the left router (hiding behind the phone) and the other phone connected to the router on the right.

Helpful links:

http://fonality.com/trixbox/forums/trixbox-forums/trixbox-endpoints/need-help-remote-sip-extension-using-cisco-7940-60

Future work:
Move the Asterisk server to a small nettop, Rasberry Pi, Beagleboard, etc.

Cisco 7911G Hardware Info

Here is some hardware information on the Cisco 7911G VoIP phones that might be useful to someone down the line thinking of integrating the phones into a HSMM-MESHÔ system.

• The power connector not same as the WRT54 series routers.  The DC power jack is a 5.5mm OD/2.5mm ID jack rather than the 5.5/2mm of the WRT routers.
• It also runs off of the POE, which is 48V rather than 12V like some polycom phones.
• The PoE chip is a TPS2375/2377 which according to the datasheet states it needs at least 30V to start power.  In experiments, I found that the phone won't turn on until at least 34V is presented to the DC power jack.  Using PoE over the Ethernet cable, it requires at least 36V to turn on.
• PoE does not appear to care what DC polarity is on pins 3/4 and 7/8, either configuration worked for me

Cisco 7911G, SIP and Trixbox

I have seen a few people experiment with VoIP phones running over a HSMM-MESHÔ link and thought this could be an interesting experiment.  I have been thinking of experimenting with VoIP for a couple of years but never found a good reason to as I use my cellphone for just about everything.  I figured I would

One day searching through eBay a couple of weeks ago, I found an auction from a local electronics warehouse that was selling 16 Cisco 7911G phones for a price I couldn't pass up.  Cursory look on-line seemed that the configuration files were adequately documented so I started off on my journey.

I was looking for a entry-level Asterisk server program that I could load on an old laptop for testing.  Searching through the Internet, I found Trixbox - which is a self-contained Linux distro with Asterisk and FreePBX already installed.  Configuration is done through a web page interface - perfect for a Linux Padawan like myself.

Setting Trixbox to talk to my Polycom IP501 phone was extremely easy: went through the extension and phone setup pages and had everything configured in less than an hour thanks to YouTube videos and online tutorials.  Same thing with a softphone application on my Ubuntu desktop - Twinkle.  The Cisco phones, however, were not as easy....

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Upgrading the phones to SIP firmware

Cisco has two different firmwares that you can load into the phone which will change it's behavior: SIP (Session  Initiated Protocol) and SCCP (Skinny Call Control Protocol).  SCCP is a proprietary protocol created and defined by Cisco, where SIP is a more open protocol and generally universal from what I've seen.  Since I don't know where this project will go in the long term, I'd rather not limit myself to one brand of phone or equipment so I decided to go with SIP.  Unfortunately the phones I bought were pulled from a business environment so it had SCCP firmware installed and needed to be changed.

Changing the firmware is a relatively easy task.  It involves having a tftp server on the network that serves the firmware files to the phone upon bootup.  After registering for a free account on the Cisco website, I was able to download the SIP9-3-1-1S firmware files and followed the instructions at this link to upgrade 7911 phones to SIP firmware:
http://lodge.glasgownet.com/tech/upgrade-a-cisco-7911-to-sip-firmware/

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The configuration file

The Cisco 7911G phones use a XML file that gets loaded during bootup for all of it's settings and configuration.  This file sets things like the time and date format, the IP address of the VoIP server, the username and password for debugging and registration, etc.  This is where it started to get hairy.

My hope was that with Trixbox, I would just go through the same motions that I did with the Polycom phone and it would be a simple matter to get it working.  Boy, was I wrong.  Trixbox apparently has limited support for Cisco phones and does not have a default configuration for the 7911G phones.  Off to the Internet I went, hoping I could find a valid configuration file that someone had posted but came up empty handed.  I found a lot of forum posts that were similar to my situation but none of the configuration files worked.

After a week of trying different configuration files, settings, searching online and just as I was about to write the phones off and re-sell them on eBay, I finally found a configuration file that worked!



<device>
   <deviceProtocol>SIP</deviceProtocol>
   <sshUserId>user</sshUserId>
   <sshPassword>pass</sshPassword>
   <devicePool>
      <dateTimeSetting>
         <dateTemplate>D-M-YA</dateTemplate>
         <timeZone>New Zealand Standard/Daylight Time</timeZone>
         <ntps>
              <ntp>
                  <name>xx.xx.xx.xx</name>
                  <ntpMode>Unicast</ntpMode>
              </ntp>
         </ntps>
      </dateTimeSetting>
      <callManagerGroup>
         <members>
            <member priority="0">
               <callManager>
                  <ports>
                     <ethernetPhonePort>2000</ethernetPhonePort>
                     <sipPort>5060</sipPort>
                     <securedSipPort>5061</securedSipPort>
                  </ports>
                  <processNodeName>xx.xx.xx.xx</processNodeName>
               </callManager>
            </member>
         </members>
      </callManagerGroup>
   </devicePool>
   <sipProfile>
      <sipProxies>
         <backupProxy></backupProxy>
         <backupProxyPort></backupProxyPort>
         <emergencyProxy></emergencyProxy>
         <emergencyProxyPort></emergencyProxyPort>
         <outboundProxy></outboundProxy>
         <outboundProxyPort></outboundProxyPort>
         <registerWithProxy>true</registerWithProxy>
      </sipProxies>
      <sipCallFeatures>
         <cnfJoinEnabled>true</cnfJoinEnabled>
         <callForwardURI>x--serviceuri-cfwdall</callForwardURI>
         <callPickupURI>x-cisco-serviceuri-pickup</callPickupURI>
         <callPickupListURI>x-cisco-serviceuri-opickup</callPickupListURI>
         <callPickupGroupURI>x-cisco-serviceuri-gpickup</callPickupGroupURI>
         <meetMeServiceURI>x-cisco-serviceuri-meetme</meetMeServiceURI>
         <abbreviatedDialURI>x-cisco-serviceuri-abbrdial</abbreviatedDialURI>
         <rfc2543Hold>false</rfc2543Hold>
         <callHoldRingback>2</callHoldRingback>
         <localCfwdEnable>true</localCfwdEnable>
         <semiAttendedTransfer>true</semiAttendedTransfer>
         <anonymousCallBlock>2</anonymousCallBlock>
         <callerIdBlocking>2</callerIdBlocking>
         <dndControl>0</dndControl>
         <remoteCcEnable>true</remoteCcEnable>
      </sipCallFeatures>
      <sipStack>
         <sipInviteRetx>6</sipInviteRetx>
         <sipRetx>10</sipRetx>
         <timerInviteExpires>180</timerInviteExpires>
         <timerRegisterExpires>3600</timerRegisterExpires>
         <timerRegisterDelta>5</timerRegisterDelta>
         <timerKeepAliveExpires>120</timerKeepAliveExpires>
         <timerSubscribeExpires>120</timerSubscribeExpires>
         <timerSubscribeDelta>5</timerSubscribeDelta>
         <timerT1>500</timerT1>
         <timerT2>4000</timerT2>
         <maxRedirects>70</maxRedirects>
         <remotePartyID>false</remotePartyID>
         <userInfo>None</userInfo>
      </sipStack>
      <autoAnswerTimer>1</autoAnswerTimer>
      <autoAnswerAltBehavior>false</autoAnswerAltBehavior>
      <autoAnswerOverride>true</autoAnswerOverride>
      <transferOnhookEnabled>false</transferOnhookEnabled>
      <enableVad>true</enableVad>
      <preferredCodec>g729a</preferredCodec>
      <dtmfAvtPayload>101</dtmfAvtPayload>
      <dtmfDbLevel>3</dtmfDbLevel>
      <dtmfOutofBand>avt</dtmfOutofBand>
      <alwaysUsePrimeLine>false</alwaysUsePrimeLine>
      <alwaysUsePrimeLineVoiceMail>false</alwaysUsePrimeLineVoiceMail>
      <kpml>3</kpml>
      <natEnabled>false</natEnabled>
      <natAddress></natAddress>
      <phoneLabel>Version 3</phoneLabel>
      <stutterMsgWaiting>2</stutterMsgWaiting>
      <callStats>false</callStats>
      <silentPeriodBetweenCallWaitingBursts>10</silentPeriodBetweenCallWaitingBursts>
      <disableLocalSpeedDialConfig>false</disableLocalSpeedDialConfig>
      <startMediaPort>16384</startMediaPort>
      <stopMediaPort>32766</stopMediaPort>
      <sipLines>
         <line button="1">
            <featureID>9</featureID>
            <featureLabel>6003</featureLabel>
            <proxy>USECALLMANAGER</proxy>
            <port>5060</port>
            <name>cisco1</name>
            <displayName>Cisco Phone 1</displayName>
            <autoAnswer>
               <autoAnswerEnabled>2</autoAnswerEnabled>
            </autoAnswer>
            <callWaiting>3</callWaiting>
            <authName>user</authName>
            <authPassword>pass</authPassword>
            <sharedLine>false</sharedLine>
            <messageWaitingLampPolicy>3</messageWaitingLampPolicy>
            <messagesNumber>1111</messagesNumber>
            <ringSettingIdle>4</ringSettingIdle>
            <ringSettingActive>5</ringSettingActive>
            <contact>cisco1</contact>
            <forwardCallInfoDisplay>
               <callerName>true</callerName>
               <callerNumber>false</callerNumber>
               <redirectedNumber>false</redirectedNumber>
               <dialedNumber>true</dialedNumber>
            </forwardCallInfoDisplay>
         </line>
         <line button="2">
            <featureID>21</featureID>
            <featureLabel>Dial 6004</featureLabel>
            <speedDialNumber>6004</speedDialNumber>
         </line>
      </sipLines>
      <voipControlPort>5060</voipControlPort>
      <dscpForAudio>184</dscpForAudio>
      <ringSettingBusyStationPolicy>0</ringSettingBusyStationPolicy>
      <dialTemplate>DRdialplan.xml</dialTemplate>
   </sipProfile>
   <commonProfile>
      <phonePassword></phonePassword>
      <backgroundImageAccess>true</backgroundImageAccess>
      <callLogBlfEnabled>2</callLogBlfEnabled>
   </commonProfile>
   <loadInformation>SIP11.9-2-1S</loadInformation>
   <vendorConfig>
      <disableSpeaker>false</disableSpeaker>
      <disableSpeakerAndHeadset>false</disableSpeakerAndHeadset>
      <pcPort>0</pcPort>
      <settingsAccess>1</settingsAccess>
      <garp>0</garp>
      <voiceVlanAccess>0</voiceVlanAccess>
      <videoCapability>0</videoCapability>
      <autoSelectLineEnable>0</autoSelectLineEnable>
      <webAccess>0</webAccess>
      <spanToPCPort>1</spanToPCPort>
      <loggingDisplay>1</loggingDisplay>
      <loadServer></loadServer>
   </vendorConfig>
   <versionStamp>1143565489-a3cbf294-7526-4c29-8791-c4fce4ce4c37</versionStamp>
   <networkLocale>New_Zealand</networkLocale>
   <networkLocaleInfo>
      <name>New_Zealand</name>
      <version>5.0(2)</version>
   </networkLocaleInfo>
   <deviceSecurityMode>1</deviceSecurityMode>
   <authenticationURL>http://mako/authenticate.php</authenticationURL>
   <directoryURL>http://mako/directory.xml</directoryURL>
   <idleURL></idleURL>
   <informationURL>http://mako/GetTelecasterHelpText.jsp</informationURL>
   <messagesURL></messagesURL>
   <proxyServerURL></proxyServerURL>
   <servicesURL>http://mako/services.xml</servicesURL>
   <dscpForSCCPPhoneConfig>96</dscpForSCCPPhoneConfig>
   <dscpForSCCPPhoneServices>0</dscpForSCCPPhoneServices>
   <dscpForCm2Dvce>96</dscpForCm2Dvce>
   <transportLayerProtocol>2</transportLayerProtocol>
   <capfAuthMode>0</capfAuthMode>
   <capfList>
      <capf>
         <phonePort>3804</phonePort>
      </capf>
   </capfList>
   <certHash></certHash>
   <encrConfig>false</encrConfig>
</device>


From this base, make sure you change the appropriate values for your setup:

• Change the timezone information to whatever you prefer
• Change the <name> tag in the <sipLines> block.  It needs to be the same as the username
• Change xx.xx.xx.xx to the IP address of the Trixbox server
• Check all the URLs to make sure they align with the files hosted on the server
• make a authentication script for the <authenticationURL> field
• Change the <loadInformation> tag to match the firmware you have loaded in the phone

Go through the Cisco Phone setup, make an extension as usual and a 7940 phone.  Then go in and replace the XML file with this one.

Make sure on the Trixbox extensions to change nat=no and qualify=never -- somehow this was restricting the registration process and not allowing it to complete.

Ongoing work: 

• Working on the NAT firewall and forwarding so that phones behind a HSMM-MESH nodes will be able to talk to the Trixbox server
• Coming up with a directory scheme for users
• connecting multiple Asterisk servers together for redundancy/load sharing?
• What is the difference between Trixbox SEP.cnf file and one that works?

I hope this helps someone down the line.

WRT54 Router Information Links

I've been doing more research into the WRT54 router hardware and thought I would share some links that I have found:


WikiDevi: Database of thousands of wireless adapters, embedded systems, images, information, etc.

http://wikidevi.com/wiki/Main_Page

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Copy of the IEEE specification 802.11-2007

http://www.ahltek.com/WhitePaperspdf/802.11-20%20specs/802.11-2007.pdf

Yes, I know it's outdated but for research on things like frequency stability, it does me just fine.

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Making 802.11G Transmitter Measurements, whitepaper by Agilent

http://cp.literature.agilent.com/litweb/pdf/5988-7813EN.pdf

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Search the FCCID database for any pertinant test data (use the FCCID found on the bottom of the routers):

https://apps.fcc.gov/oetcf/eas/reports/GenericSearch.cfm 

HSMM-MESH at the Pigman Triathlon 2012

The Pigman Triathlon long course is a half Ironman race, consisting of participants completing a 1.2 mile swim, 56 mile bike ride and a 13 mile run.  For many years, they have asked the Cedar Valley Amateur Radio Club to provide communications between the race officials, water stops, Sheriff departments and keep an overall watchful eye out for participants that need medical attention.

We traditionally run two net control locations, one dedicated to in-park portions and the running course and one about 3/4 mile away handling the bicycle portion of the race.  During the race this year, we decided to try a couple of new things, adding a HSMM-MESHÔ link between the two net control stations to use an IRC text chat and share APRSÔ data between the two spots.

On a scouting trip prior to the event, we found there was not line of site between the two shelter locations so we decided to set a node in the Gazebo's parking lot, which did have line-of-site to the North Shelter location.

Google Earth view of locations

When I got all the equipment set up the morning of the race, I was surprised on the robustness of the link.  100% link quality to both the gazebo parking lot and to the gazebo router (going through a few trees).  As soon as the router that had the IRC Chat server installed (at the North Shelter) was powered up, both computers connected to the server and never dropped out throughout the entire 8 hours.  We used the IRC server to share participant numbers for leads, sags, etc.  Simultaneously, we used an APRSÔ client, APRSIS32, with cached maps to track our chase vehicle following the last bike rider throughout the course.

Unfortunately as one of the NCS stations, I did not have enough time to test everything I would have liked (playing with output powers, recording data, antenna positioning) but as a first deployment of HSMM-MESHÔ, I would call it a success.

Antenna at North Shelter

Lessons learned:

• Antenna height can make or break your link.  During the prior testing, the panel antenna at the North Shelter was not high enough, causing a bad link.  Elevating it the day of the race solved all those issues.
• Having a deployment kit with everything needed makes setup a breeze (I came away with several ideas from this event, look for a couple of "go-kits" detailed here soon.
• Don't rely on computers having the necessary software loaded.  Always bring a flash drive with the software you'll be using, just in case you are not using your own computer.
• You really need to dedicate an operator to oversee 'special' tasks during a deployment (APRSÔ, HSMM-MESHÔ, etc) which leaves the other operators to focus on their jobs.

Equipment used:

• Gazebo at entrance to park
• WRT54GS router, modified for Part97 operation
• One 5.2dBi omni-directional antenna (Cushcraft S2403B) bungee corded to gazebo
• 3dBi antenna on other port
• 19dBm output
• Gazebo parking lot (had line of sight to north shelter)
• WRT54GS router, modified for Part97 operation mounted on tripod
• 12dBi omnidirectional antenna on tripod (~5' elevation to base of antenna)
• 3dBi antenna on other second port
• Belkin residential Gateway power supply
• 19dBm output
• North Shelter (0.75 miles distance from Gazebo)
• WRT54GS router, modified for Part97 operation
• 19dBi patch antenna (Tranzeo TR-CPQ-19), router mounted inside antenna enclosure
• 9ft tripod stand (American DJ LTS-6)
• 19dBm output

Future Ideas:

• We've already talked about using a couple of cameras set up along a particularly crowded portion of the course inside the park, monitoring them on a computer screen
• Now that we have proven it will work, possibly set up an APRSÔ display tracking first/last participants at the race official's table

First long-distance HSMM-MESH link

Last week I was able to find some free time to attempt my first "long distance" MESH link.  The link was from my house to the hill next to Nielson Hall at Kirkwood Community College.  I finished modifying two routers to be Part 97 devices by changing out the reference crystal and mounted them in a couple of surplus Transeo TR-CPQ-19 CPE antenna enclosures.

For the link setup, I placed one of the Transeo enclosures on my front porch, bungeed to keep it stationary as I didn't have a second tripod available for this test. For the location at Nielson Hill, as I nicknamed it, I had a tripod with the other Transeo enclosure attached and did my best to aim the patch in the direction of my house:

To get the best chance of a link, I left both the routers set to +19dBm initial output power (which translates to 6.275W EIRP on both ends).  I haven't come up with a good method of aiming the flat patch antennas yet, so I took my best guess.

Lo and behold, it connected right away, average of 12dB SNR margin, not bad for the first attempt:

I then began to decrease the power level on my end of the link to see how far I down I could go and still maintain the link.  Decreasing in 3dB steps (cutting the power in the power each time).  Here is a screenshot at the 13dBm output level.

Then something unexpected happened, the link completely died.  With no-one watching the other end of the link I'm suspecting that the antenna shifted such that the pattern was no longer lined up with the hill.





This test was mainly to test the distance link before heading out to the Pigman Triathlon race, where we're planning on using this equipment to create a link that will be about 0.75 miles in distance.  I am now comfortable saying as long as we have line of sight the link should work just fine.

Making GPX tracks for APRSIS32

The 2012 Pigman Triathlon long and olympic course race is coming up next month in which I am slated to be a Net Control Station.  We will also be doing an experiment simultaneously where both Net Control locations will have an APRS display infront of them, linked by HSMM-MESH routers, to track the APRS equipped vehicle that will be trailing the last bike rider through the course.

One nice feature of APRSIS32 is that it will import a GPX file and display it on a screen, essentially creating a digital copy of the race map that has APRS posits (positions) in real time.  I have made these GPX files before for a race like this so I thought I'd outline how I make GPX files for importing into APRSIS32.

Software requirements:

• Google Earth
• GPSBabel

Step 1:
Open Google Earth, zoom into route start location

Step 2:
Create a "Path" along the race route by clicking points along the route.  You can get as detailed or as simple as you like.  The more detail, the better the map will look.

Here is Google's tutorial on making paths:
http://support.google.com/earth/bin/answer.py?hl=en&answer=1113936

Make sure to change the name of the path to something useful.

Step 3: 
Save the path as a KML file.

To do this, right click on path name on the left hand pane, Save File As....

or

File > Save > Save File As...

Choose KML format, give it a useful name and save in a spot you'll remember

Step 4:
Convert the KML file to GPX format

I use GPSBabel for this.  It's a popular program that will convert a ton of different formats dealing with GPS data to another format.

http://www.gpsbabel.org/index.html

Step 5:
Import GPX file into APRSIS32

To load a new GPX overlay, go to Configure > Overlays > Import GPX file...

Browse to the location you saved the GPX file to from previous step and play with the color, opacity, width, etc.

Now, is this the only way to create GPX files?  No, it's just the way I prefer and know how to do.  You can do it relatively easily with Google Maps and a tool called GMapToGPX, drive the route with your GPS and export the data or many other ways.

VoIP on HSMM-MESH

Since working on a HSMM-MESH™ installation at Mercy Medical Center here in town has been thrown into neutral for the time being, I've been focusing my attention on playing with VoIP over the mesh.

A while ago I acquired a Polycom IP500 phone to play with and it has been interesting to say the least in getting it working.

First off, the phone requires a FTP or TFTP boot server on the network to pull the application software and configuration files at bootup.  After many trial and error sessions I finally got the phone to boot from a TFTP server on my desktop and can make SIP phone calls directly between my computer and the phone, no SIP server required (after finding out that the sip phone address is SPIP@<ip_address>).

The only logical progression is to move the TFTP server from my computer to the HSMM-MESH™ router that the phone is plugged in to so I don't have to have a computer running to get the phone booted.  Of course, nothing is that simple.  Much consternation ensued again until I stumbled onto a forum post advising that apparently there is a bug in the Kamikaze 7.09 OpenWRT firmware that a dependency package for atftpd, libreadline, is not in the 7.09 repository so you have to install it manually from an earlier repository.  Easily done by executing the following command before installing atftpd:

ipkg install http://downloads.openwrt.org/kamikaze/7.06/brcm47xx-2.6/packages/libreadline_5.1-1_mipsel.ipk

The next goal will be to move the Polycom to a separate mesh node and try to make a call over the mesh.


Relevant links:
http://support.polycom.com/PolycomService/support/us/support/voice/soundpoint_ip/soundpoint_ip500.html

https://forum.openwrt.org/viewtopic.php?id=8495


ToTD: It would probably be a good idea to start keeping copies of any downloaded packages on a flash drive.  Never know when I'll have to do field work on this project without access to the Internet.

Inaugural post

I figure there are many projects that I'm working on that is of interest to others so I thought I might as well start a place to document and share them.  Bear with me on format and how it evolves, it's likely to change a lot.

73 de KC0ALC