Managing your network remotely with Cellular Routers
When you leave your home or office you likely see signs that tell you there is a "Wi-Fi hotspot" in the local coffee shop, pancake house, or hotel. You may plan to use that Wi-Fi hotspot to perform some important management tasks on your Windows network or even just answer some important business email. In some cases, you might even have such important business that you call the hotel and verify that they really have Wi-Fi available. However, many times, when you get there, that Wi-Fi hotspot just does not work as promised. Perhaps the Wi-Fi is slow, the signal is weak, or you are told that "the Wi-Fi is down today" (can you tell I am speaking from personal experience here?).
It was for reasons like these that I invested in a cellular data "card" (while it is not actually a card) and then went one step further and bought a cellular router and antenna. Let me tell you exactly what I use and how it has helped me.
Step 1 - Cellular Data Device
Let us define a "cellular data device" as a piece of hardware that connects your computer or network to the cell tower which connects you to the Internet. I call them generically "devices" because they come in various forms. I originally used these back when you would take a cellular phone, buy a special cable, and a cellular modem. Back then, I was lucky to get anything close to 9600 baud and I was doing direct-dial, not through the Internet.
Today, you can get cellular data devices that run at 3G and 1x/EV-DO speeds. That will get you between 384kb to 7.2Mbps, at the absolute fastest (which I have never seen). Keep in mind that most cellular carriers will cap you at 5GB per month and then you have to pay overage charges. These devices come in the form of: USB, PCMCIA, tethered-cellphone, mobile broadband router, or internal in your laptop.
When I went shopping for a device I used the following criteria:
- Compatible with a cellular router (ie: the router supports this device)
- Capable of supporting an external antenna
- Different carrier than that of my cellphone (where I might use tethering) so that I will always have connectivity to two carriers in case I have coverage issues with one or the other
- Not built into my laptop (so that I can use it with the external router, so that I can use an antenna, and so that I can use it on multiple devices)
My cellphone is an AT&T iPhone so I opted to go with Verizon for the cellular data device. I also liked them because I wanted to make sure I had the best coverage and speeds possible and Verizon constantly brags about "the network" (their coverage being good).
Note that I want to use the cellular device with a router so that I can support a network of computers, not just a single computer. The antenna is to increase the range if needed but would not always be required. Also note that there is always the option to buy an amplifier to connect between the cellular device and the antenna. I figured that I would try it with the antenna first and I could always add the amp later if needed. Plus, I did not want too much equipment if I did not need it.
After considering my requirements, comparing the list of devices compatible with my cellular router and the list of devices in stock at my local Verizon store, I ended up with the Verizon UM175. Even though there were other more desirable USB cellular devices, the UM175 was the best option, considering my requirements. And, best of all, it was free after rebate (and with contract).
Figure 1: Verizon UM175
Step 2 - Cellular Data Router
Next, I needed a cellular router to support any of the devices I wanted to take with me when I travel. For example, not only does my laptop need Internet access but also my wife's laptop and perhaps I will bring some other network device on a longer trip. Or, what if my cable modem at my home office goes out for a few days? With a cellular router, I could connect my existing home office wireless AP that was connected to the cable modem directly into the cellular router and gain instant access to the Internet, without any reconfiguration of my home office network devices.
I suppose I should have listed step 1 as "select a cellular router" as I actually selected the cellular router first and then used that to select the cellular device that was compatible with my router. Still, in terms of what I bought, I bought the cellular device first, then the cellular router.
The cellular router I chose was the Cradlepoint CTR-500.
It is very small and reasonably priced (MSRP of $199). It fits in the palm of my hand and I was amazed at all the features it provides in such a small package. It connects to the cellular WAN through the USB cellular device. On the LAN side, it offers 802.11g Wi-Fi and an Ethernet jack that you can connect to a switch and then to any device you want. Additionally, it has a nice web-based interface that tells you everything that is going on.
Step 3 - Put it all together
Once I had the cellular device and the cellular router, I had to make it work. Fortunately, this was not too hard. I activated the cellular USB device on my laptop and then connected it to the cellular router. I then connected my laptop to the Wi-Fi network. Using my web browser, I went to the default gateway IP address of 192.168.0.1 (the Cradlepoint provided my laptop an IP address through DHCP). Then, I used the default username and password to login. I configured the device to use WPA2 for strong Wi-Fi security. Here is what the basic administrative interface looks like:
I like the SPI (stateful packet inspection) firewall and NAT functionality. To allow me to remotely manage a network device, inbound, to the Cradlepoint, I have set up port forwarding of the RDP (remote desktop protocol) using the virtual server feature. The Cradlepoint even knew the name and IP address of the device I wanted to enable the RDP to. Here is what it looks like:
Honestly, the Cradlepoint CTR500 has a ton of features such as:
- Email notifications
- Schedules of when to connect to the cellular network
- SNMP and SYSLOG
- Failover / Load Balancing
- Traffic Shaping
- Content Filtering
- and even RIP Routing
Needless to say, I was impressed with the feature list of this tiny router.
Step 4 - Using Cellular to Manage your Windows Network
Now, when I entitled this article "Managing your network remotely with cellular routers", that leaves the direction of management in question. Actually, I have used cellular both to access the Internet so I could manage another network AND I have used cellular to allow a network to access the Internet so that I could manage it remotely.
In other words, I could be using this cellular while staying in a hotel to manage my work network. OR, I could use cellular as a secondary or primary network connection for, say, a remote office and then manage it from another office. Even better, I could use a cellular device, router, and antenna to allow my whole family access to the Internet from say an RV or boat (that I wish that I had). In fact, they sell specific antennas and amplifiers for boats, truckers, and RVs that connect to your cellular device.
Recently, Verizon released the "MiFi 200", or their Mobile Hotspot that incorporates a cellular device and cellular router in one. The downside is that the cellular device can only be used with that cellular modem (couldn't take it and put it on an PC or MAC). And, the Mi-Fi does not have the option to use an external antenna.
Of course the biggest problem in managing a network remotely is getting a quality connection at the remote network to make the remote management possible. And, you want the bandwidth and latency to be at tolerable levels that make the remote management usable as well as enjoyable.
Once you have that connection you have a few different management toptions:
- RDP - as I mentioned above, you could RDP either outbound of your laptop to the work server OR you would allow inbound RDP on the cellular router to the virtual IP.
- VPN - make sure that you enable VPN passthrough on the cellular router
- SSH or telnet - for those command line junkies out there
In this article we learned how you can use cellular Internet routers to manage your network remotely. We covered selecting your cellular device, choosing your cellular router, and putting it all together to allow you to manage your Windows network. I hope that you too will get excited about using cellular to access your Windows infrastructure.