TCP/IP Monitor

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Mike6158
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TCP/IP Monitor

Post by Mike6158 » Fri Nov 12, 2004 10:45 am

Hello,<p>I'm new here and I have a question. A friend of mine is connected to the internet via a wireless network. The system is comprised of at least 4 "hops" (radios). He's on the end of the one leg of the system. Every now and then a radio along the leg will "lock up" and his node will go down. The connection is restored by driving to the site and rebooting the radio. We've been trying to figure out a cheap way to monitor the radio connection and reboot the radio (power it down and then back on) if the connection times out. As I understand it each radio has an ethernet port. If we could somehow monitor the port for "keep alive" activity or something like that we could use a simple timing circuit to cycle power to the radio if the connection "died" for more than XX seconds/minutes/whatever.<p>Any ideas?
"If the nucleus of a sodium atom were the size of a golf ball, the outermost electrons would lie 2 miles away. Atoms, like galaxies, are cathedrals of cavernous space. Matter is energy."

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dacflyer
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Re: TCP/IP Monitor

Post by dacflyer » Fri Nov 12, 2004 12:05 pm

my idea is for you to come up with some kind of a watchdog circuit...this circuit monitors the info coming in/out of a unit...if the unit stops sending any info , after a certain time the unit will be forced into a re-start / reboot...
i do not know your units..i can only tell you that a watchdog is what should help you...
perhaps someone here can tell you more..i think there was a artical in N&V not too long ago about watchdogs..
good luck

Mike6158
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Re: TCP/IP Monitor

Post by Mike6158 » Fri Nov 12, 2004 12:09 pm

Thanks... I'm familiar with watchdog circuits as they pertain to PLC programming. I'm not sure how to go about "watching" the data of an ethernet connection without corrupting the data.<p>Thanks
"If the nucleus of a sodium atom were the size of a golf ball, the outermost electrons would lie 2 miles away. Atoms, like galaxies, are cathedrals of cavernous space. Matter is energy."

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dacflyer
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Re: TCP/IP Monitor

Post by dacflyer » Sat Nov 13, 2004 6:13 pm

ahhh. i see... well that was my opnion..but perhaps someone here will know more.. ;)

mojorizing
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Re: TCP/IP Monitor

Post by mojorizing » Sat Nov 13, 2004 7:55 pm

This thread might help:wifi forum
A poster recommends a possible hardware solution on the second page of the thread.<p>[ November 13, 2004: Message edited by: mojorizing ]</p>

hp
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Re: TCP/IP Monitor

Post by hp » Sat Nov 13, 2004 9:47 pm

Well, usually when an access point fails the network act lights will stay off. You could use this to your advantage. <p>Just put a phototransistor in front of an LED that will stay off / on durring a failure write a program for a microcontroller to monitor that phototransistor and reboot the ap if there is no network activity for x minutes / seconds.<p>Then to make sure the thing doesnt keep rebooting just send a nonstop ping from one side of the network to the other. That should keep some activity going..<p>[ November 13, 2004: Message edited by: hp ]</p>

Mike6158
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Re: TCP/IP Monitor

Post by Mike6158 » Sun Nov 14, 2004 4:47 am

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by hp:
[QB]Well, usually when an access point fails the network act lights will stay off. You could use this to your advantage. <p>Just put a phototransistor in front of an LED that will stay off / on durring a failure write a program for a microcontroller to monitor that phototransistor and reboot the ap if there is no network activity for x minutes / seconds.<p>Then to make sure the thing doesnt keep rebooting just send a nonstop ping from one side of the network to the other. That should keep some activity going..
<hr></blockquote><p>
:p I like all of it but the non-stop ping part. I was thinking that there is a "keep-alive" "bit" or whatver that gets passed between the master and slave radios. Kind of a "Hey Fred you still there? Yeah Boss I'm still here" kind of thing. If that's the case then the activity light would pulse on a specific time cycle and that would replace the ping command.<p>Great idea... Thanks a ton...<p>PS- I was reading about the Watchdog Timer that Gary Peek designed (10/04 issue of N&V). That seemed like a good solution for this problem. I would rather do this with a PIC if I could though...<p>There might be a flaw in my keep-alive theory... If the radio locks up that doesn't necessarily mean that it will drop the keep-alive activity... I need to talk to my buddy and get a radio model number...<p>[ November 14, 2004: Message edited by: NE5U ]<p>[ November 14, 2004: Message edited by: NE5U ]</p>
"If the nucleus of a sodium atom were the size of a golf ball, the outermost electrons would lie 2 miles away. Atoms, like galaxies, are cathedrals of cavernous space. Matter is energy."

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Re: TCP/IP Monitor

Post by dyarker » Sun Nov 14, 2004 9:24 pm

The manufacturer and model number of the radio units would help.<p>Where would a "keep-alive bit" come from without traffic? Unless the radio units where already smart enough and talking to each other.<p>You don't need continuous pings. Set the watchdog closest to the user to reboot it's radio after one minute of no traffic. The next radio's watchdog to one minute ten seconds, etc. etc. (Assuming a radio unit can reboot in less than ten seconds. This should prevent un-needed reboots when a radio further down the line hangs.)<p>Only send a ping when there has been no traffic for 20 seconds. This gives at least three chances to avoid a reboot in case of short temporary link outages (like near by lighting stike, flock of birds flying through line-of-sight of antennas, etc.). If there is no regular Internet traffic, a ping every 20 seconds isn't getting in the way of anything.<p>Cheers,
Dale Y

Mike6158
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Re: TCP/IP Monitor

Post by Mike6158 » Mon Nov 15, 2004 3:20 pm

Well... My buddy threw a kink into the works. The radio sits at the top of a tower. Some of the towers are a couple of hundred feet high. He wants to monitor the Cat5 line (somehow) for activity. Apparently someone makes a widget that the Cat 5 "passes thru" and when it detects that the radio has locked up it cycles power... with a time delay so that it won't constantly cycle power...<p>He's going to get the model number for me when he gets back in town...
"If the nucleus of a sodium atom were the size of a golf ball, the outermost electrons would lie 2 miles away. Atoms, like galaxies, are cathedrals of cavernous space. Matter is energy."

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