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Automatic fallback to a backup digital repeater
John Barrett
Has anyone put together a program that will periodically test data connectivity to the current "access point" (dstar repeater), and if that repeater is non-responsive, automatically switch through a list of repeaters round robin until it finds an active connection ??
Would there be any interest in a program to do this, and perhaps a bit more ?? I'm setting up what amounts to a mobile network hot spot with backhaul transport agility that will be capable of backhaul over D-Star, 2.4ghz Mesh, and 4G wireless, with the routing selected automatically based on the current availability and reliability of each potential backhaul link. End users (other hams, personel associated with a served agency) will connect via hardwire ethernet or Part 15 802.11B/G, and gain access to services through a web portal installed on the routing computer. Security will be implemented by blocking all traffic from the Part 15 network until such time as the end user logs into the web portal, thus allowing the the portal to validate their identity and load the account profile which will contain information about the "roles" which the account may access. The majority of roles will grant access to services provided directly by the portal computer (webmail, weather radar, etc) where the portal is acting as a concentrator/cache such that many users viewing the same information produce no more traffic than a single user viewing the same information. However, each role in the system will optionally have an associated profile of protocols/ports/addresses which will allow the portal to open a very specific set of holes in the firewall for the end user, allowing direct access to the backhaul network to support applications that cannot be handled by the web portal directly (streaming video, file transfers, etc) Comments appreciated :) John AE5ET Barrett |
erwestgard
--- In D-STAR_23cm@..., John Barrett <john.ae5et@...> wrote:
I'd need to see a diagram here. BTW we have never seen one of these units fail. How I might set this up is to have the mini web site on the Linux computer behind the repeater. The Linux box would have connectivity to various services and each would be a hyperlink. If your goal is to reach the Internet, you could try several ways= try each link in turn, which might each be a proxy server. Mini Portal Web Site - Internet via 3G - Internet via WiFi - Internet via DSL I have convinced our group to not put Internet on our primary access points. This way they cannot be hacked, and routine Internet access via this system is not part 97 friendly by my reading of it. If you *have* to have Internet, you can bounce via the repeater to an ID-1 someplace that is on someones cable modem, etc- and set up a remote gateway. Mixing Internet traffic into our limited half duplex links risks overloading them, but if you control it you can be OK. If you have Linux at both ends you could develop some scripts, etc that would test this. |
Haven't you heard of a firewall? They are fairly new but I think they'll catch on
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I use m0n0Wall on a WRAP board for NJ2MC's Internet access. We get the usual script kiddies and DOS attacks but it fights them all of with ease. Mark On 10/17/2009 07:14 AM, erwestgard wrote:
I have convinced our group to not put Internet on our primary access points. This way they cannot be hacked |
John Barrett
The question is not if the unit has failed, but if the unit is in range of an "access point" (DStar repeater, Mesh node, or 4G wireless tower) at any moment in time.
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I've uploaded a diagram of the proposed system. This entire setup is going to be installed on my pickup truck along with hard mounted antennas, and a 30ft pneumatic mast for the rare occasions where I can't establish a link with the antennas mounted to the overhead rack. Hehehe (let the flame wars begin) The portal computer is going to be a windows box running IIS with all the portal software written in C#.. I'll do my best to keep it clean enough to port over to a Linux/Mono server if anyone is interested. The portal database will be MySQL so that will not be an issue. I've been programming C# and ASP.NET for the last 5 years and I am quite sick and tired of having to do all the low level grunt work in PHP that gets done for me automatically when I'm working in C#.... especially when it comes to accessing databases. Hyperlinks are DEAD -- give me AJAX :) RAD to the HILT :) When I talk about services on the portal, I mean things like a webmail system tied into Winlink, a Weather Radar web app that downloads and caches the imagery so that instead of 20 people downloading an image every 5 minutes, the server downloads it once, and then serves it out as needed to the 20 users (thus reducing the on air traffic to a minimum). A full blown DotNetNuke content managment server with forums, news/RSS feed capability. The "mini" server will be the one built into the public access router in case the portal server fails, and it will not be capable of granting access to the backhaul networks unless I decide to add an SD card to store the login and service databases. 99% of the time, end users will have access to everything they need on the portal. Only on rare occasions will an end user be allowed any sort of direct access to the backhaul links. When backhaul access is granted, it will be handled by opening holes in the firewall specifically for the services that the specific end user is allowed to access, as defined in the portal servers database. erwestgard wrote:
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erwestgard
Weather maps (we had a big storm here a while ago - SkyWarn was all over it) are interesting - the old ones are not useful and you really almost want to stream/multicast new ones. We have not tested multicast on our systems. One idea is to stream the weather feed to a local server and then let folks share it locally. It would seem another weather application is to upload streams of remote observer weather- the actual wall cloud etc.
The one thing we see- people are used to "live" updates on breaking news events and live video streams. On the firewall question, modern expolits seem to utilize outbound sessions. Conflicker attemps to contact several hundred out of several thousand possible domains? On a thin network, Windows Update is also a problem as 80 meg of updates @90kbs is a big issue. And what does a firewall do when one of your partners brings an infected laptop and plugs it in behind the firewall as happens to us annually. The philosophy we have is to find out what the actual public service job is, and do it with different tools than the agencies already have. |
开云体育To test connectivity…. ? Ping –t ?10.0.0.1 ? From: D-STAR_23cm@... [mailto:D-STAR_23cm@...] On Behalf Of John Barrett
Sent: Saturday, October 17, 2009 6:04 PM To: D-STAR_23cm@... Subject: Re: [D-STAR_23cm] Re: Automatic fallback to a backup digital repeater ? ? The question is not if the unit has failed, but if the unit is in range |
John Barrett
Dont get me started -- I'm installing a video system with night vision capability on the truck :) It stores to VHS but there are plenty of places to tap into the system and run the feed over to the computer for video capture and streaming. It seems that video is more suited to an HSMM network to me in any case. I look at dstar as better suited as a faster replacement for AX.25 packet -- mail, web, and file transfer. For video I'd much rather look at a Mesh network or ATV. I've got a 1.2ghz transmitter and reciever I'm playing with, and a 440 transmitter that both my cable ready TV and a little cheapie USB tv reciever I snagged on ebay picks up on like a champ :) Might have to make a 1.2 up/426 down ATV repeater out of it :)
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On the data side of DStar -- is there a way to broadcast data to all listeners ?? there is your multicast equivalent -- or are we stuck in the IP-centric model ?? (I guess I'll learn more about what the 1.2g data capabilities are when I get my ID-1 hooked up later this week) erwestgard wrote:
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开云体育With the ID-1, the connection is just like a port on a hub. No more, no less. So the answer would basically be yes, it should support multicast. BUT, unlike wired connections, it is real easy for packets to be dropped with an RF signal, so your mileage may vary. The ID-1 implementation depends on TCP/IP for error detection and correction, not the RF. ? Now, as far as what happens with the controller and broadcast in a D-STAR stack, I have no idea what it will do. That’s the most prevalent use at this point. ? Ed WA4YIH ? From: D-STAR_23cm@... [mailto:D-STAR_23cm@...] On Behalf Of John Barrett
Sent: Sunday, October 18, 2009 12:23 PM To: D-STAR_23cm@... Subject: Re: [D-STAR_23cm] Re: Automatic fallback to a backup digital repeater ? ? |