The MPLS WG Archive

["dave o'leary" <doleary@juniper.net>]

At 08:05 AM 6/8/00 -0500, David Allan wrote:

>IMHO only in a simple case "look thog, fiber go dark", which can only deal 
>with gross physical defects, and I have predefined recovery strategies 
>(such as the virtual ring proposals the group has entertained).
>
>Dave

The general consensus (as far as I could read it) at the Barcelona OIF
meeting in August is that the variations between different optical vendor
equipment in terms of ability to recognize and report "faults" is so wide
that at this point it only makes sense to start with a least common
denominator (like a binary "up/down", as Tony suggests), since there
is easy path toward richer signalling at this point.

I've certainly been known to misread the group, and I recognize that
this is an IETF rather than an OIF list, and there is enough common
membership and optical clues lying around here that if I have
mischaracterized the situation, it would be great if someone could
enlighten me / us.

thanks,

                                                 dave

>-----Original Message-----  From:   Juan Diego Otero 
>[SMTP:jote4102@alu-etsetb.upc.es]  Sent:   Thursday, June 08, 2000 6:20 
>AM  To:     mpls@UU.NET  Subject:        MPLS and fast reroute.
>
>Hi,
>
>In IEEE Communications Magazine (December 1999), there is an 
>article  written  by Tony Li called "MPLS and the Evolving Internet 
>Architecture". In page  41,  talking about fast reroute, Tony says: 
>"...MPLS can also be used in a  manner very similar to synchronous optical 
>network (SONET), where no  signaling is necessary to perform the 
>protection switching of the LSP.  This  results in restoration times 
>competitive with SONET." My question is:
>
>Can anybody explain me how MPLS can be used as SONET in  switching a LSP 
>after a faliure, with no signaling?
>
>Thanks a lot.
>
>Diego Otero  UPC (Universitat Politècnica de Catalunya)