The MPLS-OPS Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] Re: Hierarchical LSPs
Hi Sylvia, FA is basically a higher bandwidth LSP. On top of this LSP you can combine(nesting) one or more lesser banwidth LSP's. FA provides a kind of abstraction, that is a link between FA ingress and egress. Thus hiding the details of that particular portion of the network. There are many scenarios where we need this kind of nesting. One of the scenario is Inter-area or Inter-As LSP setup. Here an FA is setup in a single area and is used by a LSP from another area that need to traverse this FA LSP area. Thus the LSP will be setup without knowing the details of the FA LSP area. Secondly in GMPLS. Say the backbone is a TDM or a Optical network. And access network is a PSC network. Bandwidth allocation in TDM or Optical will be in higher chunk, than what it is in packet. So in this case a FA is setup in the Backbone, and multiple LSP's from access will start setting up over this FA. I hope it helps. Regards, Amit. ----- Original Message ----- From: Spice Sylvia <falsesylvia@yahoo.co.uk> Date: Tuesday, April 12, 2005 4:43 pm Subject: [MPLS-OPS]: Hierarchical LSPs > Hi, > > Can someone please help me understand why the > "capacity" of the wire itself cannot be treated as the > outer most constrain, rather than making a > hierarchical association. > > In other words: > > N1---N2----N3---N7--N4---N5--N6 > > I see that folks define a FA from N3 to N4, inside > which another FEC from N2 to N5 is created and another > N1 to N6 hierarchy is put inside it. > > Howevr in all cases the CAC/setup is done from N1 to > N6. > > Is there a reason why the FEC hierarchy is built? Why > does the "capacity of the wire" not act as the FEC > itself? > > Is "maintaining the state" of each inner LSP on > intermediate node a problem? > > -brgds > Sylvia > > > Send instant messages to your online friends > http://uk.messenger.yahoo.com > > ------- > The MPLS-OPS Mailing List > Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml > Archive: http://www.mplsrc.com/mpls-ops_archive.shtml > > MPLScon 2005 - May 16-19, NYC, NY > http://www.mplscon.com/ > ------- The MPLS-OPS Mailing List Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml Archive: http://www.mplsrc.com/mpls-ops_archive.shtml MPLScon 2005 - May 16-19, NYC, NY http://www.mplscon.com/ |
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