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Re: [lwip-users] PPP gives the IP, Gateway and netmask as follows, I can
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From: |
Sergio R. Caprile |
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Subject: |
Re: [lwip-users] PPP gives the IP, Gateway and netmask as follows, I cannot ping... |
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Date: |
Wed, 23 May 2018 09:35:38 -0300 |
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User-agent: |
Mozilla/5.0 (Windows NT 6.1; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 |
Looks like you've got yourself a lot to read before you can actually do
some networking with your hardware. Good luck.
I suggest you start here:
https://en.wikipedia.org/wiki/Point-to-Point_Protocol
Then, small pieces of advice:
- your device is a host in a network that does not belong to you. You
don't assign static addresses, you take what the network assigns to you.
Try not to interfere or you will have issues.
- you have way too many unknowns in your equation, try to remove some of
them until you can manage the scenario. I would learn some basic PPP,
install a pppd server on a computer on my lab so I could see the
traffic, first try to connect a computer so I'm sure it works, then try
to connect my device to that server over a serial cable. Once I know for
sure that my device is working fine, I can go fight the cellphone
network. The other advantage is that I can even test all my apps inside
my device routing through my server, and move to the cellphone network
whith the app working at least on a well behaved network. Cellphone
networks are usually not well behaved and you'll have some other issues
to cover for.
- if you decide to skip your local tests, then at least learn some PPP
and check what is going on in the wire.
PS: perhaps when you read about PPP you'll discover that '~y' is not
'~y' but '~ΓΏ' which is 0x7E 0xFF which is really FLAG ADDRESS, which is
just the start of the HDLC frame carrying all the other protocols in the
TCP/IP protocol stack over the PPP protocol stack. Enjoy your journey.