YES NOPE9 wrote:
> As more and more things are controlled over the internet ; What schemes a=
re best for connecting embedded devices to [ laptops and smart phones and t=
ablets ] ?  =20
>
> I have some presumptions =3D=3D>  Most connections do not require high sp=
eed data transfer. Simple messages are sufficient.  Simple while extensive =
ID schemes are best.....
>
> What do PIClisters suggest ?
I would suggest using a client-server architecture. The embedded devices=20
connect to the server which feeds them instructions on what to do and=20
gathers data from them. Users interact with the server not directly with=20
the devices.

1: there are many situations (involving NAT and/or stateful firewalls)=20
where it is easy to connect outbound to a server on the internet but=20
difficult or impossible to receive connections from the internet. These=20
are likely to become ever more common as IPv4 exhaustion bites.
2: centralised data is easier to secure, back-up etc
3: you are likely to want to aggregate data from multiple nodes
4: serving web pages is quite a complex task it's just about possible to=20
do it on a pic18 but only with horrible compromises on things like=20
concurrent users and/or buffer sizes.
5: it centralises any authentication requirements (important as your=20
user count increases.

Depending on the workload and reliability requirements the server may be=20
something like a beagleboard, a repurposed desktop PC or a proper server=20
and it may be located in a datacenter or under your desk. The important=20
thing is it can receive connections from the internet on a reasonablly=20
stable public IP address and has enough cpu and ram to do TCP properly.
--=20
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