Re: [ECOS] Multiple PPP interfaces in single unit

[Nick Garnett <nickg at ecoscentric dot com>]

Ãyvind Harboe <oyvind.harboe@zylin.com> writes:

> Is it possible to use the PPP stack to chain multiple devices via
> the serial ports?
> 
> I.e.:
> 
> Unit 1
> 
> Serial 1 talks to PC via PPP
> Serial 2 talks to unit #2 via PPP
> 
> Unit 2:
> 
> Serial 1 talks to Unit #1 via PPP
> Serial 2 talks to Unit #3 via PPP

We cannot do this at present, it's an explicit limitation of the
current implementation. The expectation was that most eCos devices
would be solitary remote devices that were dialled into, or dialled
out. So a single PPP connection would be the ususal case.

The main problem is that the PPPD code was designed to instantiate a
separate Unix process for each PPP channel. So there are a lot of
global variables that would need to be duplicated in some way. The
code within the TCP/IP stack itself should not need changing, however.

This is not a trivial job unfortunately, and anything we do would
seriously inhibit any efforts to update the PPP code from the BSD
repository. 

-- 
Nick Garnett                    eCos Kernel Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts


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