Friday, March 30, 2007
Meraki - Dallas freenet
Entrepenuership in action. If you want to see how another mesh deployment is going, cruise on over to http://www.dfwfreenet.org/ and see how they are doing. they have a great wiki and a node map up and running. So far they only appear to have 5 nodes up and running but I could see this going big. Support them by laying out a measeley $49 bucks for your own node and go to town!
Meraki Node - Management Details
The Meraki mesh node I got has been up for a week now and here are my thoughts. Well, first of all, It is pretty neat. 'nuff said. I had some questions that I posed to Ben Chambers of Meraki and here are the answers.
The first thing I wanted to know was why it beacons every 500ms instead of 100ms. Twice per second did not seem very much and considerably off the norm. Ben stated that, "As far as the beacon interval goes, the reason is basically that if you have a fairly high number of repeaters (say, 20) within range of each other, 10 beacons per second per node gets pretty excessive." This makes total sense to me.
The next question was whether there was a way to configure the node or at least monitor it. I was told that because it was a free node belonging to the Meraki "Free the Net" project I would not be able to configure it but I would be able to monitor it in a variety of ways:
1. I can see if it is up by associating with it and browsing to http://my.meraki.net/ where I would see a splash page. Click on each image to see a larger version of the image.
2. I can Select the "Advanced" link in the upper left and get a page that lets me run a throughput test to the internet.
3. I can select another link on the advanced page that allows me to set a static IP and some other functions.
4. I can also get to a page that is just for my repeater at http://sf.meraki.net/myrepeater/00:18:0a:01:10:b3 which looks like this:
5. I can also get more data from a more public view of the Meraki network from this URL http://sf.meraki.net/overview which shows me connected to another mesh node way over in Potrero Hill, at least a mile away.
6. I was also pointed to a site where there is XML data for Google earth. http://sf.meraki.net/earth . You must save the source as a KMZ file on you hard drive and open in Google Earth.
After which, it now looks like this in Google Earth. Notice the mesh links (I made them yellow, the better to see them with.)
Which now allows me to go down to sea level and see the line of site to the other link
Pretty impressive. My next step would be to get some Meraki Minis and connect them to the mesh and see how they work out. More fun for next time :-) Talk to you then.
Monday, March 26, 2007
My Own Mesh Node - Meraki comes through!
Last Thursday, Ben Chambers and Jessica showed up on my doorstep from Meraki Networks with APs in hand. I was psyched! We were about to hook up an outdoor node to the Meraki San Francisco trial.
They brought over a Meraki outdoor AP, a toolbox and a lot of cable and got right to work. We went up on the roof to check it out and find a spot to put it. Then we went indoors and talked about how/where to bring the cable in. The unit is powered by a proprietary POE (Power over Ethernet) injector which I plugged and hooked up to my switch.
Ben went back up onto the roof and connect the AP to a plumbing vent pipe. It came with what appears to be a 12dbi antenna (I will check and get back with the details).
It got link and pulled a DHCP address from my home router and started broadcasting the SSID FreeTheNet and we were done.
We chatted awhile and then they left. The were super nice and obviously loved their jobs. Later the unit started upgrading itself and is now running a newer OS than what it originally had. I checked that evening and found I was up on the website at http://sf.meraki.net/ but unfortunately none of my neighbors had a Meraki node close enough to attach to mine. I am going to drop in on Ritual Coffee later this week and get them to join the network as well as some of my neighbors.
Tuesday, March 20, 2007
Meraki Wireless Repeater Makes Extending WiFi Easy!
Meraki is now offering a great way to extend you WiFi network. Inexpensive repeaters. The Meraki Mini is a $49 (there is also an outdoor model for $99) AP you just put in your window and connect it to a MuniWiFi network or your own internet connection and then, according to their site, you just add more repeaters to make a mesh, "The more Minis that are out there, the bigger the network. And you can plug right into the repeater instead of going wireless."
I like this idea a lot. So much, in fact, that I use something somewhat similar myself. But is has a few drawbacks that are not mentioned on the website.
In my house we have one AP/Basestation/Router at the DSL D-marque and 3 WiFi repeaters throughout the house. I use the Apple Airport system so I have one Airport Extreme connected to my DSL router and 3 Airport Expresses connected using WDS (wireless distribution system) which mean none of my Airport Express units need a cable drop. It works really well, I can connect to any of the APs and surf the internet and I can stream music from my desktop or any connected laptop to any of them using Apple's AirTunes, even my Dell. The drawback is that every hop from the repeater reduces the bandwidth considerably as each device, with only one radio, has to spend half it's time talking to your laptop and half forwarding the signal. Wikipedia states, "...throughput in this method is inversely proportional to the number of "hops", as all traffic uses the same channel. For example, client traffic going through one relay station before it reaches the main access point will see at most half the maximum throughput that a directly connected client would experience." For me, this is fine as I only have 3Mb/s internet access but for larger mesh networks it begins to be a problem. Meraki suggests, "To boost the signal, connect every tenth one to the Internet." It is unclear from Meraki's documentation if the use separate channels or radios for the back haul.
The system also has a really great web-based management application called Dashboard which they give away for free. Dashboard allows the Network admin to monitor the network, change it's configuration and it has a built in billing feature if you wish to setup a hotspot or be your own neighborhood service provider.
The last really great thing about the Meraki solution is the ability to repeat the relatively weak MuniWiFi signal and project it into your home. This will allow users of these networks, especially one's in older homes with Lathe and Plaster or Stucco and chicken-wire construction to get a lot more signal strength and thus increased speeds. In fact, Meraki is already working in San Francisco to implement a Mesh network in and around my neighborhood. I have signed up for it and we will see where it goes. I will blog about it as it happens. Check it out at http://sf.meraki.net/
Anaheim Muni-Fi and Earthlink ready for Wi-Fi Phone Beta Testing - We need details!
Good news for those of us watching the VoWLAN emergence but I have some questions:
It appears as if the service is tied to their phone. There is this quote in the release, "'What separates our Wi-Fi phone from others is its ability to work over EarthLink's municipal Wi-Fi networks,' said Steve Howe, EarthLink's senior vice president of voice."
- Does this mean that other SIP phones or dual band phones will not work?
- Is this an attempt to control the hardware and service.
- Has anyone tried using a different phone over the Anaheim network?
Later on it also mentions that the Accton system is and ATA (Analog Telephone Adapter) based system. This would be similar to Vonage's home adapter. Again, more questions, can you use the handset while roaming about the network or just when in range of your own ATA base station?
Lastly (and in my opinion, most importantly), is it encrypted or are folks going to be able to sniff my call and play it back with VoiPong or something similar? Why do people always think of security last?
There are many questions we still have no answers to. If you know any, drop me a line.
Friday, March 9, 2007
RFID Tags for Apple devices. Wi-Fi Enabled Apple Remote, iPod and Other Peripherals
The idea, described in Apple’s patent “RFID network arrangement” is simple. Put RFID transceiver into a network wireless base station such as Airport Express or Airport Extreme and put RFID tags on other devices that you want to connect to Wi-Fi network.
All network configuration information, including communication parameters, SSID info, radio channels, encryption keys, etc; can be stored in the base station. When RFID enabled network device is brought in to close proximity of the base station, RFID transceiver collects this information and writes it to read/write RFID tag on the network device. When this device is turned on, it reads configuration data and security keys from RFID tag and establishes secure network connection.
That’s it. From a user stand point - you just bring you Macbook within a feet of your Airport Express and the network is set up. You don’t even have to have a Macbook on at the time. RFID info to the tag can be read/written without additional power source. Then you turn your laptop on and it’s already on the network.
RFID tags also solve the problem of how to connect various “dumb” devices that don’t have appropriate user interface (like screen or keypad) for easy configuration:
- This may be the final piece in the puzzle to make Wi-Fi iPod a reality. Put WI-Fi chip inside, add RFID tag and that’s it. You take your iPod to your base station and then turn it on. Your iPod is another device on the network. Of course, passing Wi-Fi synchronization data to the iPod was already technically possible. But RFID tags make the process so much easier.
- One of applications mentioned in the patent is Apple Wi-Fi Remote for:
“… controlling the operation of the iTunes music software provided by Apple computer… Such a remote control might have buttons for a variety of playback-oriented functions, such as play, pause, skip forward, skip back, volume control, etc, but such a device might not include an alphanumeric keypad or display device suitable to allow configuration of the device to operate over a wireless network. Using the teachings herein, such a remote control could be configured merely be bringing it into proximity with the computer or network base station…”
- Extending your WI-Fi network. You can have RFID transceiver on Airport Extreme and RFID tags on Airport Express. Then you just sync them and plug Airport Express where you need extended Wi-Fi coverage.
- Wi-Fi enabled network printer and any other peripheral. Again, put Wi-Fi chip in it, slap RFID tag on, sync. Your printer is another device on the wireless network
Looks like Apple did it again. The basic idea is so simple and obvious in hindsight, yet it opens so many new possibilities that there will be lot of people wondering “Why didn’t I think of that earlier”.
Building a Voice Capable WiFi Network
Building a wireless network that supports data traffic is hard enough but trying to support VOIP over your WLAN (also known as VoFi) can be a nightmare. To make matters worse, when you ask your vendor how to make Voice work on your WLAN they explain you will need 2X-3X as many APs as you needed for data. "Sure I do", you respond. Confident that the sales person from your vendor just wants to sell you more APs. Or, better yet, you turn to your trusted VAR and he suggests another site survey. "Right, another one", you say, with that knowing look in your eye and a sinking feeling that you are being strung along. You feel like the guy who brings his car in for a tune-up and gets told he needs a complete overhaul.
Well, I have nothing to sell you and no agenda that I will benefit from by saying this but your infrastructure vendor and your VAR are absolutely correct. You probably will need more APs and you sure as heck will need another survey. Lets find out why, shall we?
Unlike Email and web access, slight lags or delays in traffic or small losses in connectivity will completely destroy calls. A person who has access to the Internet durring a meeting in a conference room is far less likely to lose his cool for small delays than when he is on the phone with an important client.
You see, wireless handsets are much lower powered compared to the access points they talk through. A typical AP is usually set to communicate at 100milliwatts (mw) whereas the typical handset is roughly 5mw. This makes it very easy for the handset to hear the AP but very hard for the AP to hear the handset when it is far away. Also they are far less resilient to fragmented packets, retries, packet loss etc.
So what can I do? Well the simplest thing to do would be to ensure that the handset is always at the same power as the AP. That means either increasing the power on the handset or, more likely, lowering the power on the AP. This will mean, of course, that you will need more APs to cover the same area.
For example here are 4 APs at 100milliwatts:
Here are the same APs but now set to 5mw instead, notice the gaps in coverage:
In order to compensate, we must add many more APs to fill in the holes, all configured to run at 5 mw:
As you can see, much better. Now, though, our main issue is channels. APs that overlap thier signal on the same channel take away from the usable bandwidth. We want to ensure we do not trample the signal from another AP so we must adjust the channel plan.
Also, remember we only have 3 channels to work from.
Cisco, at this point recommends the following:
That explains why I limited the seen signal to -67dbM making all the other signal fall off and appear grey.
In a week or two, we will discuss debugging Voice issues and setting MOS scores.