Re: The "Presentation" Layer

["Aaron Bartell" <aaronbartell@xxxxxxxxx>]

Oh man, that explanation (which I haven't heard described before) really has
the wheels turning in my head.  Kinda makes a guy rethink some ideas I had
formalized.

Have you done any JXTA implementations? And if so what was the scenario?

Aaron Bartell
http://mowyourlawn.com


On Fri, Jul 18, 2008 at 8:37 AM, john e <jacobus1968@xxxxxxxxxxx> wrote:

> P2P is when the two sides on a connection can be either a client, a server,
> or both. Specifically, client/server is an architectural approach which is
> simple, robust, and scalable (i never said client/server is a bad thing).
>
> By designating a specific role (client or server) to each side it makes
> implementing a scalable and robust distributed app simple. A client always
> initiates a request to the server, and a server simply processes requests. A
> client also typically knows the address of the server wher to send the
> requests to.
>
> If you have simply TCP/IP, you actually have a peer-to-peer network. Each
> program can connect to any other program and take on whichever role. But
> distributing code over different processes which are "peers" (i.e. they are
> equal) is more difficult to implement.
>
> You can say that APPN is peer-to-peer and TCP/IP is not, because APPN
> implements additional functionality that is specifically for peer-to-peer
> networking such as discovery of neighbor peers. In TCP/IP you have to
> implement this yourself with e.g. UDP. In APPN, the LU6.2 logical unit is
> the "peer" on the network. LU6.2 supports different protocols for dealing
> with peer-to-peer networking.
>
> A green-screen terminal is also a peer in the network, but in practice it
> acts more as a server, and the program running on the host is the client.
> E.g. the program requests the terminal to display a format. So most of the
> time a terminal takes on the server role. However, at first, when logging
> into the system, a terminal initiates a session and has the client role.