Re: Moving right along ... Switching Type

[Ben Mack-Crane <Ben.Mack-Crane@tellabs.com>]

I agree that the G.805 model is extremely useful in analyzing networks,
and thus in designing control protocols for networks.  I think that some
of the confusion regarding the semantics of fields (like Switching Type)
may be due to the lack of a coherent model of the network under control.

If we have a coherent network model it should be easy to clearly define 
what the control parameters mean.

G.805 is the best model I've seen so far...

Regards,
Ben

neil.2.harrison@bt.com wrote:
> 
> Watching this discussion unfold it seems that many would benefit from a read
> of G.805 on functional arch and what layering/partitioning mean.  I saw
> someone (Zhi I think) refer to 'adaptation' (ie the required functionality
> at client<=>server boundaries) but I wonder if most people understand what
> he meant by this?....which is also at the root of what Maarten is talking
> about below, ie it all depends on where trails start and terminate....or put
> another way 'clinet layer link connections = server layer trails', where
> each clinet layer link connection can be served by a different technology
> trail.  You can't start a trail using technology X and terminate it using
> technology Y, this makes no sense as Maarten states below.....in transport
> networks trail termination points must come in matching (technology) pairs.
> 
> regards, Neil
> 
> > -----Original Message-----
> > From: Maarten Vissers [mailto:mvissers@lucent.com]
> > Sent: 01 November 2001 11:03
> > To: Yakov Rekhter
> > Cc: Zhi-Wei Lin; ccamp@ops.ietf.org
> > Subject: Re: Moving right along ... Switching Type
> >
> >
> > Yakov,
> >
> > It depends on what your definition of "OXC" is...
> >
> > - if it is a box with fibers connected to it it can be a
> > SDH/SONET ADM or cross
> > connect, in which case it makes a lot of sense... the 1GE
> > physical interfaces
> > are terminated and the packets are mapped via GFP (Rec. G.7041) into
> > STS-3c-Xv/VC-4-Xv or STS-1-Xv signals for further transport.
> > It is becoming
> > popular already to do this...
> > I.e. the transport network is very capable to mix and match
> > different interface
> > types at its edges. Some other examples: DS3 - network -
> > OC48, 100ME - network -
> > 1GE, E1 - network - STM1, 1000BaseX - network - 1000BaseT
> >
> > - if it is a box with just an optical fabric, it doesn't make
> > sense of course...
> > 1GE port on R1 and OC-48 port on R2 "don't speak the same language".
> >
> > Regards,
> >
> > Maarten
> >
> > Yakov Rekhter wrote:
> > >
> > > Zhi-Wei,
> > >
> > > > <z>Maybe this is one where we need to ask individuals
> > with operational
> > > > experience and have some experience with service
> > provisioning whether
> > > > having one end with Ethernet and another end with OC-48
> > sounds like a
> > > > configuration that makes sense?
> > >
> > > Let me see if I understand your proposal. Consider the following
> > > example:
> > >
> > >    R1---OXC1---OXC2----R2
> > >
> > > where the TE interface on R1 is a collection of GigE ports,
> > and the TE
> > > interface on R2 is a collection of OC-48 ports. Are you saying that
> > > establishing an LSP between R1 to R2 makes sense ?
> > >
> > > Yakov.
> >