The Fluke Networks LinkSprinter represents a huge departure from the company's previous product offerings. Fluke Networks at one time had a near monopoly in the handheld network testing market, only to see its dominance crumble to competition from JDSU. The LinkSprinter represents Fluke's reinvention of its entry-level product. More important, the LinkSprinter reinvents the way IT professionals will view handheld network testing.
The bottom line is that handheld network-testing tools have been too expensive, too slow, and too cumbersome to carry as part of your regular toolkit. All too often it was easier for installers to "rock and roll" their network installations and test only when things didn't work. The test tools cost too much, and the tests took too long -- long enough to really bite into how many network drops you could install in a day.
The industry has been screaming for a handheld network test tool that is fast, self-documenting, and affordable enough for every tech to carry one. The LinkSprinter 100 (US$199, wired Ethernet) and LinkSprinter 200 (US$299, built-in Wi-Fi) answer the call.
The LinkSprinter is an exploratory attempt at a truly inexpensive network test tool. Just ask any electronics design engineer about handheld platforms, and they'll tell you the biggest cost is that hunk of glass. Fluke Networks has removed that expensive hunk of glass by leveraging the smartphone in our pockets. The LinkSprinter 200 combines a built-in 802.11b/g Wi-Fi access point with a Web server, allowing any Wi-Fi-enabled, HTML5-savvy browser to serve as the "glass" for the tester. The LinkSprinter 100 also includes the internal Web server, but you'll need to access it through the wired network.
Testing with LinkSprinter
Both LinkSprinters still give you quick and dirty test indicators in the form of tri-state LEDs, but your browser is now the place to get more detailed test information. Below are a few examples of how the LinkSprinter can help with your post-installation checklist.
- Do I have power over PoE (Power over Ethernet), and if so, how much? Not all PoE is created equally, and cable length, kinks, and poor terminations all have an impact on usable power. Knowing how much power is flowing over PoE translates into knowing whether that access point 30 feet in the air is going to work or not. LED Status: OFF = no PoE (< 20V) RED = high voltage (> 57V) YELLOW = low voltage (< 37V) GREEN = normal voltage
- Am I negotiating link correctly with my upstream switch? One of the most basic tests, link is different for gigabit versus 100-megabit connectivity. Make sure link is negotiated over all four pairs for gig, but only two pairs for the older 100 meg. LED Status: OFF = auto-off activated after 3-minute timeoutBLINKING_GREEN = waiting for initial link or link lostSOLID_GREEN = linked OK
- If I'm on a DHCP network, am I getting correctly formed DHCP replies? Can I get DHCP and can I get it at least three times in a row? What you don't want is your test device "hanging onto the old DHCP" address as you move from data jack to data jack. Once you have an HTML5 browser associated with the LinkSprinter 200, you can reconfigure it for a static address. LED Status: RED = DHCP failed after 1-minute timeout, or duplicate IP detected GREEN= DHCP acquired, or static IP with no duplicate address
- Can I get to my default gateway? If you can't talk reliably to your default gateway, nothing else matters. You ARP to things in the same subnet as you, but it's the gateway that gets you to the outside world. LED status: OFF = connected to cloud for claiming unit (if DHCP and WWW are both green) RED = no ping responses (some gateways have PING disabled) YELLOW = missed one or two pings GREEN = received all three pings
- Can I get to an Internet resource such as a Web server? This last test is actually two in one. First, can you do a DNS lookup? Second, can you get to a resource using something like a Web browser? This configurable test can be set up for just about any TCP port or as a simple ICMP ping. LED Status: RED = DNS name lookup failed or no ping/port responses YELLOW = missed one or two ping/port responses GREEN = received all three ping/port responses
I'm excited that any HTML5 browser can be used to get the full GUI on the LinkSprinter, but it has implications for how test data is stored. If the LinkSprinter were a fat app, you could potentially store test data on your iPhone or Android device. But then, platform support might be limited to those platforms. Fluke made the choice to support any device with an HTML5 browser, but that means the LinkSprinter currently must have a connection to Fluke's LinkSprinter Cloud Service for data uploads. Your HTML5 device is simply the control panel.
I say "currently" because the LinkSprinter is a platform that could morph radically based on market pressures, and I'm hoping that someday an API will be available that allows application developers to create a fat app front end capable of more advanced network testing. What makes this platform so different from a hacked-together Raspberry Pi is that the LinkSprinter can harvest data from the first three layers of the OSI model. Electrical information from Layer 2, LLDP (Link Layer Discovery Protocol) or CDP (Cisco Discovery Protocol) from Layer 2, and ping and WAN connectivity from Layer 3. The Raspberry Pi's Ethernet interface is really USB, and nothing I've found so far has allowed me to get to the electrical portion of the Ethernet interface.
The LinkSprinter doesn't do any data testing at gigabit speeds, but its electrical interface does allow it to probe the interface to see if it will negotiate a link at gigabit speeds. The compromise is that on a gigabit switch, the LinkSprinter will test the gig link, but perform the data testing at 100Mbps instead -- not a horrible compromise, but you should be aware of it.
The LinkSprinter Cloud Service runs on Heroku and Amazon Web Services. During the initial setup process, the serial number of your LinkSprinter needs to be "claimed" by your cloud service account. This sets up the AES-256 credentials the LinkSprinter will use for all of its cloud communications. The cloud service provides a common data collection point for any number of LinkSprinters, with filtering tools to make it easy to create PDF or CSV reports on any subset of your testing data. Thanks to a free format comment field, installers could easily put in the data jack number combined with data from LLDP or CDP switches to give you a fairly decent start on your network inventory.
I'm hoping Fluke will settle on a slightly higher number of tests per subscription level. Currently, you get 100 tests per LinkSprinter per month for a monthly fee of US$9.95, or 1,000 tests per LinkSprinter per month for a monthly fee of US$79.95. On the plus side, usage during the first 120 days after registration is both unlimited and free so that you can get comfortable with your new tool. After that, the first 10 tests per month continue to be free. You also have the option to surge outside of your subscription level on a month-by-month basis.
The Fluke Networks LinkSprinter is sold through Amazon, and it's available at a price just about anyone could afford. To get the price down to consumer levels, some compromises had to be made (see the list of pros and cons below). But the LinkSprinter is a network test tool anyone can use -- not just the network techs with years of experience -- and it's cheap enough to put into a lot of hands. Imagine how many tech support calls could be avoided if the branch office manager could plug in a LinkSprinter and see if he gets four or five green lights.
- One-button operation
- Pairs with LinkSprinter Cloud Service for test aggregation
- Will test gigabit connections, but will only run Internet tests at 10/100 megabits
- Test results can be filtered and exported to PDF or CSV
- PoE test will tell you how much power is available
- Can run on PoE or AA batteries
- Can comment or annotate test results via your HTML5 browser
- Available on Amazon
- Uses LLDP or CDP for switch information discovery
- Access (to LinkSprinter 200) limited to 2.4GHz 802.11b/g
- Confirms only Layer 2 gig operation, not Layer 3 or higher
- LinkSprinter Cloud Service currently lacks an API
- Clumsy if you do not have DHCP on your network
- No DHCP option parameter demux yet, so you see only the option itself
- Uses only LLDP or CDP to discover upstream device information; no SNMP support yet
- Must push results to the cloud; no on-premise counterpart
- Can only store up to four test results, but not to the phone or tablet
- Can only upload results over the wired Ethernet interface
- Initial setup must be on a wired network with DHCP
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