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 Subject :Question on connectivity.. 2015-02-18- 06:22:13 
WB6TAE
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Joined: 2014-05-01- 23:48:12
Posts: 70
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When working with nodes with low quality links, I have frequently seen a case where I can connect to a (distant) node in a browser using a URL of the form http://nodename:8080/ (Eg. a link from the mesh status page)

I then receive the default re-direction response from /www/index.html - - so, I know I have an TCP (http) connection to the distant node. But, after that, the redirection target url (the status page) never opens and the connection times out.

Any ideas as to why the connection to the default static landing page succeeds and the connection to /cgi-bin/status does not?


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 Subject :Re:Question on connectivity.. 2015-02-18- 10:59:29 
KG6JEI
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Joined: 2013-12-02- 19:52:05
Posts: 516
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My first out on a limb guess would be page size on a lossy link would have something to do with it (I've see  it once or twice myself)

The first page is a mere 549 bytes.  That's ~1/3 of a max frame size so you don't need as long of a clear opening in RF to get it out (549bytes over 1mlillion bits = very rough time it takes to send the packet in seconds) while the main page is larger (I don't have generated size off hand but I know for sure it is larger) this creates two issues 1) a larger packet is more likely to get interrupted than a short packet 2) There may be more packets to get lost.


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Last Edited On: 2015-02-18- 11:05:38 By KG6JEI for the Reason Max frame is 1500 bytes not kb
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 Subject :Re:Re:Question on connectivity.. 2015-02-18- 11:40:05 
WB6TAE
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Joined: 2014-05-01- 23:48:12
Posts: 70
Location

Thanks Conrad, I suspect you are right. The html on my status page is ~2700 bytes.  That, plus TCP/IP overhead, would, as you note, require two packets. Plus, since it's TCP, each packet must be ACKed.  So, I can see that over a weak radio link one small packet would be more likely to succeed than 1 full and one mostly full packet.




[KG6JEI 2015-02-18- 10:59:29]:

My first out on a limb guess would be page size on a lossy link would have something to do with it 

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