Subject: RE: DiffServ MPLS over Ethernet (L-LSP vs E-LSP)

From: "Gray, Eric" <[email-masked]>
Date: Mon, 21 Oct 2002 13:38:28 -0400

Curtis,

	See below...

Eric W. Gray
Systems Architect
Celox Networks, Inc.
[email-masked]
508 305 7214

> --- [snip] ---
> 
> 
> It works fine until you put an ethernet switch in place and try to put
> more than 1 Gb over a 1 GbE.  This is true for any situation where
> more than one ingress going through the switch to one egreess.

Realistically speaking, how often do you expect
to see Ethernet switches being used between LSRs
within an MPLS domain?  In the (possibly rare)
case where this occurs, how likely is it that
such a switch is MPLS unaware?

> 
> If there are no ethernet switches (that being layer2 devices, don't do
> MPLS) then you don't need Layer 2 priority.  That would be true for
> point to point ethernets between LSR.
> 
> Curtis
> 
> 
> > > --- [snip] ---

---

From: Curtis Villamizar <[email-masked]>
Date: Mon, 21 Oct 2002 13:51:16 -0400

In message <[email-masked]
> [email-masked]

An ISP would be better at answering that.  I know that ISPs have
considered using GbE and 10GbE within POPs that have more than one
router as a means to interconnect access routers that serve lots of
low speed links.  This keeps the interface count down on the core or
aggregation routers instead using less expensive L2 switch interfaces
and the access routers typically do not source/sink enough bandwidth
to exceed the ethernet.  I'm quite sure some have done this and are
using MPLS over some of these ethernets.

I don't work for a ethernet switch vendor and I also don't hear all of
the requirements that come to my employer, but so far I haven't heard
anything from ISPs that would indicate that they are using MPLS
capable ethernet switches.  I must admit that could also be because I
never asked about this and our equipment is more core oriented so it
was never mentioned.  AFAIK the ethernet switches are not MPLS
capable.

Curtis