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Re: realtime networking




Related work has been done in our lab at Stony Brook. Please check out

	http://www.ecsl.cs.sunysb.edu/rether.html

- Kartik

On Thu, 3 Sep 1998, Mack wrote:

> Hi.
> 
> I consider doing some work on realtime networking protocol over ethernet.
> (under linux of course)
> 
> 1. Has anyone already done something similar ?  I couldn't find anything,
>    but I want to be sure before I start working.
> 2. Any interesting ideas/suggestions for the implementation ?
>    Currently, I plan to implement something similar to token-ring over
>    ethernet, and have an RT_sendto() function that receives the usual
>    staff plus priority for the packet.  Needless to say, all hosts on the
>    ethernet are assumed to use this protocol, so under no circumstances
>    will there be a collision.   (no arps running around, etc...)
>    TCP/IP + arps and the rest of the usual networking staff will work on
>    this network although not being realtime, but will not affect the
>    realtime communication.  This will be achieved by having IP call
>    RT_sendto() whenever sending a packet, and use the lowest priority.
>    IP itself cannot be made realtime even if you increase its priority,
>    because if the target does not exist in the local arp table, you must
>    send arp, get arp reply, and only than transmit your packet.  Also, tcp
>    has a retransmit mechanism, which is not a good idea here.   If the
>    packet got lost, I dont want an auto retransmit, but an error, letting
>    the application know that the packet wasnt sent on time.
> 
> Any interesting thoughts about this ?
> Will such project be useful for more people, if I do it ?
> 
> 	Yoav
> 
> 
> RT Linux Home Page: http://rtlinux.cs.nmt.edu/~rtlinux
> 


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Kartik Gopalan

kartik@cs.sunysb.edu

http://www.ecsl.cs.sunysb.edu/~kartik

Ph(res) : (516)-216-2389

Ph(off) : (516)-632-8436

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RT Linux Home Page: http://rtlinux.cs.nmt.edu/~rtlinux