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Author Topic: Making "MiFi" work  (Read 20899 times)
WO7R
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« on: March 03, 2014, 04:17:17 PM »

I am blessed with a remote location and want to operate from my "real" home remotely.

One big problem is internet access.  I have a Flex 5000a and want to "remote" it, including the bandscope, one way or another.

To do that, I need internet.  I need more than a phone line.

There are NO internet providers out where my shack is.  The only solution that has a chance of working is basically a stripped down cell phone.  It's called a "MiFi" and I have good connectivity with it.  Works great when I'm just "at the shack" using it.

The problem is, I don't know how to "find it".  So, if I want to have things like the A/C power controller on the internet and controlled by a browser, I need to be able to interactively discover its web address.

AT&T says you can't have a server but what I hope they really mean is you can't have a fixed IP address.

I do own a modest web site, with statistics, so I can capture the web address of anything that accesses that.  I could also have at least something NATed behind the WIFI that accessed the page (a simple CHRON with WGET for your Linux freaks; for the rest, just assume I can "call" for a web page of my choice every so and so minutes). 

That's almost enough though not quite, to make the A/C power controller, and the other PCs, available from the outside going in.

I'd like to use Ultra VNC to at least start up the Flex 5000a before using CAT remotely for most of the control function.  The audio, being virtual to start with, should be the easy part.

But, the main problem is simply having a reliable way to find the darn thing on the internet.

Anyone know how this is done?
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AA4PB
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« Reply #1 on: March 03, 2014, 05:33:28 PM »

When they say "no server" they mean no server, not just no fixed IP address. What you need is a commercial EVDO wireless service. It can be implemented in a number of ways including a "wireless modem" that has a fixed IP address and a built-in router and firewall. All you have to do is plug a computer or other device into the Ethernet port. You need to talk with your provider, explain what you want to do, and see what they have available.

If you have a wireless modem that can be configured to use a dynamic DNS service, the modem will send its IP address to the DNS server and you can access it by using a domain name (like www.myremote.com). The problem is that you have to pay a monthly fee for the DNS service and your provider will likely not provide you with a compatible modem if they don't want you running a server on your consumer account in the first place.

Most ISPs do not permit you to operate a server on a non-commercial account because they assume that having a server means a heavy traffic load. If they catch you they can cancel your account. A friend of mine was told to take down his test server that only had a couple of beta testers connecting to it - and that was ASDL service.

Take a look at http://www.sierrawireless.com/productsandservices/AirLink_Gateways_Modems.aspx
« Last Edit: March 03, 2014, 05:37:32 PM by AA4PB » Logged
WO7R
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« Reply #2 on: March 03, 2014, 05:47:57 PM »

But "sever" here is going to be a power controller and my remote station control.

Nothing that anyone else isn't already doing on a standard residential account to run remote on this message board.

I think the bigger issue is the technology.  Can I make it work?

If I get caught, I get caught as far as being a "server" goes.  Somehow, I don't think the overall load from this is going to strain my account limits or get them very excited.  What they don't want is someone trying to run a big time web service.  This is little more, in terms of the load and the technology, than a glorified Skype.

I talked to them before I bought this and they raised no objections.  They specifically said it was very little different from a regular WiFi controller and that I could set up my own firewall and so on.  But then again, they were salesman, so maybe they didn't understand all the distinctions.
« Last Edit: March 03, 2014, 06:00:11 PM by WO7R » Logged
AA4PB
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« Reply #3 on: March 03, 2014, 07:04:30 PM »

Have you asked if they can give you a fixed IP address (you may have to pay extra for it)? Look into whether the modem can be configured to use a DDNS (Dynamic DNS). If so, you can sign up and get a domain name from one of the DDNS providers and then enter the info into your modem. Every time the modem gets a new IP address it notifies the DDNS server. When you try to connect to that domain name the DNS server hands you the current IP address of your modem.

Other than that I don't know of any way that you can make it work. Essentially what you have is a small dedicated server and there is no way that you can connect to it without knowing its IP address.
 
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WO7R
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« Reply #4 on: March 04, 2014, 06:45:25 AM »

The way that might work with the set-up as is is to have the remote shack access a known web page on my site.

It would be a "three ring circus" where I would have 1) my home system, 2) my shack, 3) my website.  All three would exist.  If 1) and 2) access specific pages on the web site, my web site's statistics would show the current IP address.

So, I would know what the most recent address was.  I think I can make that work.  The larger question is that there will be actually more than one address behind a NAT and I'd have to be able to reach the power strip or else have a low power Arduino or Raspberry Pi that I could access through a known port.

That's the part (I think) that could be a little sticky.

The other option would be to leave the "Pi" up all the time and try to keep everything going that way.  It would be the "NAT" box and I'd access everything through it, including the power strip.  Since it would be the first box, then there'd be no problem with the initial port (probably 22, using SSH) through which I could then reach everything else.  The Pi could be operated via a battery with an AC "behind" it, but run off the battery if the power is out.  If the battery ran out, I'd have to do the 20 minute drive to the shack, but otherwise presumably wouldn't have to go out much.
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AA4PB
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« Reply #5 on: March 04, 2014, 07:00:17 AM »

Yes, you could get the IP address that way as long as it doesn't change too often. The other thing you'll have to watch out for is if your "wireless modem" device has a firewall that blocks incoming connect requests. With a regular router you can configure it to accept incoming requests and forward different ports to different addresses on the LAN. Success depends on how tightly they've got the wireless modem locked down.
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WO7R
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« Reply #6 on: March 04, 2014, 12:31:04 PM »

They claimed the MiFi device was pretty dumb.  They told me explicitly that I needed to provide my own firewall.

We'll see if that's true Smiley .
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K0JEG
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« Reply #7 on: March 11, 2014, 03:44:56 PM »

A club member set up a remote station using a cellular modem. We did a presentation about it at a recent meeting:

https://www.youtube.com/watch?v=8ahuPi8xk_U

Verizon will sell you a static IP address, but it's not cheap. Expect a hassle when asking them to provision your cell modem unless you go with a business account.
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N3HEE
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« Reply #8 on: March 27, 2014, 05:33:56 AM »

Perhaps you could use a satellite internet provider?  DishNet, Huges, Excede all offer Internet service.
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N9RO
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« Reply #9 on: March 27, 2014, 03:58:35 PM »

Larry,

Just noticed your post so you may have already solved this issue?  If not, here is an easy way to obtain the unknown remote IP provided there is a PC at the remote location.

Using the ARP command which displays the entries in the Address Resolution Protocol (ARP) cache you can obtain the IP and MAC for devices seen on your network.  Below is a little PowerShell script that could be scheduled to run at the DHCP lease time interval and it will do the needed ARP command select the line with the MAC address you provide (the device you need the IP from) and then it will Email you the new IP.   

=======================BEGIN===================================
# This script will find the IP for the specified MAC address
# and send the Internet Address, Physical Address and Type
# to specified Email address.
$newip = arp -a | Select-String -pattern PUT-MAC-ADDRESS-HERE
$SendDate = Get-Date
Write-Host $SendDate "  Sending New IP Info"
#SMTP server name
$smtpServer = "SMTP-SERVER-HERE"
#Creating a Mail object
$msg = new-object Net.Mail.MailMessage
#Creating SMTP server object
$smtp = new-object Net.Mail.SmtpClient($smtpServer)
#Email structure
$msg.From = "fromid@xxxxx.com"
$msg.ReplyTo = "replyto@xxxxx.com"
$msg.To.Add("toid@xxxxx.com")
$msg.subject = "New IP Address"
$msg.body = $newip
#Sending email
$smtp.Send($msg)
=====================END=============================

You will need to fill in the needed info and it will need to be run on a Windows PC that has PowerShell (Win 7/8).  You could get very fancy with this and do far more but this very simple script is a quick and dirty solution for getting an unknown IP at a remote location provide you know the MAC address of the device of interest.  I just used it to discover the IP on my Flex 6500 but I give no guarantees and use at your own risk.

Good Luck.

73,
Tim N9RO
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AA4PB
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« Reply #10 on: March 27, 2014, 04:08:41 PM »

He needs to find the dynamically assigned IP address for his remote from the control site so that he can initiate a connection to the remote site.
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N9RO
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« Reply #11 on: March 27, 2014, 06:07:52 PM »

If you schedule the script to run after the lease period it will give you the new dynamically assigned IP.  The script should be set to run after every lease period so you always have the latest IP.  You could add a test so it would only Email a change.  This will Email the IP info from the remote site to the control site provided he has a Windows PC at the remote site that can run the script, you should have to do nothing but make sure the script is in the scheduler.

73,
Tim N9RO
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WG8Z
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Posts: 200




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« Reply #12 on: April 02, 2014, 03:48:59 PM »

Put  echolink software at your remote site.  Then when you want to find the WAN address just open echolink software from anywhere and click info on your remote site... This will give you the current IP. I used this when traveling to find the Wan IP of my Router for the HRD station at home in the shack. Saves on DDNS fees.
Also this gives you another VOIP channel.
YMMV
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