Subject: Re: Control and Forwarding functions

From: [email-masked]
Date: Tue, 04 Sep 2001 23:31:09 +0000

> /Loa
> -------------------
> > The main 
> > characteristic of a Connection Oriented service is the 
> > long term association required between two end points.
> 
> This makes IP a connection oriented technology! 

I don't know what you mean by "IP technology" - To be precise, TCP 
is a connection oriented (CO) transport over connection less (CL) network
layer. If you mean forwarding of IP packets - it is not clear
to me how did you infer that two routers need to establish
any associations before they can forward packet to one another.

> > The process of how such association is established is 
> > not important. It is also not important if the 
> > connection doesn't begin or end at some hosts (why we 
> > need to use ISDN or X.25 definitions of connections?).
> 
> If you say that anything that even remotely could be forced into a
> e-2-e signalling scheme is connection oriented technology, well 
> then the definition loses all content. It is the e-2-e compatibility
> negotioation and the dependency on the continous operation
> of the connectivity that constitutes the connection orientation. 
> y
 
If MPLS was truly a connectionless technology we won't need
to read number of drafts on LSP recovery mechanisms :-). Traffic
Engineering is often cited as the most useful application (perhaps 
the only useful application according to some as every thing else 
that MPLS does can also be done equally well with other IP only 
protocols). Traffic engineering using MPLS involves the setting up
of label switched paths (LSP) possibly with explicit routing and 
with bandwidth guarantees (for label switched paths). Is n't it 
similar to setting connections?

Cheers,

--brijesh
Corona Networks

---

From: Eric Osborne <[email-masked]>
Date: Wed, 5 Sep 2001 00:58:54 -0400

> any associations before they can forward packet to one another.

Well, they generally need to establish a routing protocol adjacency.
Does that make IP CO?  If not, then LDP's not either.

> to read number of drafts on LSP recovery mechanisms :-). 

We don't need LSP recovery mechanisms to make MPLS work.  We need LSP
recovery mechanisms to make MPLS work
faster/better/smarter/harder/whatever.  

> Traffic Engineering is often cited as the most useful application
> (perhaps the only useful application according to some as every
> thing else that MPLS does can also be done equally well with other
> IP only protocols).

Some people cite that, yeah.  But since when does perceived utility of
a particular technology define its underlying characteristics?

> Traffic engineering using MPLS involves the setting up

Yes.  Well, sort of.
I don't have to explicitly route TE LSPs.
And I don't have to request any bandwidth.
Does that mean that TE signalling is connection-oriented unless it
doesn't request any bandwidth and doesn't ask for a specific path?

eric