RE: Moving right along ... Switching Type

[neil.2.harrison@bt.com]

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.
>