[Sois-tcons] Telecon this Friday

[Abhijit Sengupta]

At 6/1/2005 09:55 AM, Jane K. Marquart wrote:
>Dear TCONS/OBL members,
>
>We'd like to have a telecon this Friday at 11:30 EST to discuss plans for 
>getting out the books.  I've included the following from Steve to get us 
>thinking about it before the telecon.
>
> >The key issues are how we define the QoS and where we split the stack for
> >the red books. There are currently two views on this, both of which I agree
> >with (something about training as a physicist and getting to grips with
> >particle/wave duality):

Please recall how the QoS specification comes from TCOAS - basically, 
defining bounds on different service parameters like delivery time or 
jitter, bandwidth etc. Your definition of QoS needs to be something that 
can readily be mapped from specification from TCOAS.

> >1. Split TCONS/OBL at the bottom of TCP/IP and above the sub-network level
> >where the QoS is done. This is the view that Rick put forward. In this case
> >OBL offers a set of services which provide different QoS to TCP/IP and
>TCOAS
> >(and possible TCONS protocols).
> >2. Split TCONS/OBL below the sub-network level so that the QoS services are
> >generic to all the underlying buses. This is the view that Dai put forward.
> >It preserves the role of TCONS looking at the QoS issues (in line with the
> >charters) but is disadvantageous if all the QoS if handled differently by
> >the various buses.

In either case then, transport or network layer functionalities do not care 
about QoS specification which might be a serious problem. Please recall 
that QoS specification from TCOAS is not concerned with whether the source 
and destination applications are on same subnetwork or not - in fact the 
applications do not have a clue (in general) where the recipient 
application is running.

Abhijit

________________________________________________
All personal and professional opinions in this email are my own
and do not represent, in any way, the opinion or policy of JPL
________________________________________________