[c-nsp] gigabit ethernet ring for metro ethernet deployment

[Marian Durkovic]

On Sat, Jan 06, 2007 at 11:18:51AM +0200, Saku Ytti wrote:
> On (2007-01-05 21:21 -0500), Bill Wichers wrote:
> 
> > >> RPR is a technology I feel needs to be implemented in Cisco's switch
> > >> lineup. At this point RPR is not where it needs to be, I have queried
> > >> Ethernet". EAPS accomplishes this but is one vendor centric (Extreme
> > >> Networks)
> > 
> > I would love to see Cisco implement something like this. It would be great
> > for protected Metro Ethernet deployments, and would be a lot better (for
> 
> RPR is excellent technology, but it requires hardware support, so
> what ever cisco gear you have today, it's not going to be doing
> RPR when the code is there.
> It's crying shame that RPR standard bodies didn't spec RPR-lite 
> or whatnot that would be software equivalent of it (with of course
> poorer performance), replacing EAPS and all other proprietary hacks.
> Your best bet of having something similiar in cisco, is to hope
> cisco will implement their own EAPS like software hack, question
> you should address to your account team.

Well, what's really needed in (not-only) ring ethernet topologies is the
advanced layer-2 with the ability to forward L2 frames via the shortest
path without any of the links being in blocking state. 

There are currently two initiatives covering this, one is IEEE's 802.1aq
Shortest Path Bridging and the other is IETF's TRILL.

The 802.1aq presentations were mostly given by Norman Finn - see e.g.
http://www.ieee802.org/802_tutorials/july05/nfinn-shortest-path-bridging.pdf

So the ideas how to properly handle (not only) ring ethernet topologies 
definitely exist, but as said above, the customer demand will as usual 
decide if/when this will get implemented.   


	With kind regards,

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----   Marian Durkovic                       network  manager         ----
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----   Slovak Technical University           Tel: +421 2 524 51 301   ----
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----   812 43 Bratislava, Slovak Republic    E-mail/sip: md at bts.sk    ----
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