The MPLS WG Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] ATM-LSR do they use OSPF/IS-IS or PNNI??
Actually Option 1 does, and will continue to happen in the real world. Apart from ATM's use as a Traffic Engineering plane in "conventional" IP networks, it is used in a number of other service architectures. The common factor for these services is that they provide high revenue to the Service Provider. Currently MPLS does not do this (actually this is unfair...MPLS may well provide high REVENUE, but it does not provide high EARNINGS). Note, that MPLS is beginning to offer "value-added IP services" such as VPNs, but it's not clear yet whether these services actually operate at a profit, or just at a lower loss than best effort (ie. Internet) IP services. For the near to mid-term future, the DSL market will ensure that bother the pure ATM and the SIN model will continue at the edge of the network. The DSL market is very dependent on local regulatory and market conditions, so I don't want to make specific comments, but in general the view is that ADSL specifically can generally demonstrate an ROI within 2 years, assuming the ADSL has an ATM network behind it in order to support high revenue voice services. Cheers, Geoff At 17:38 18/04/01 +0800, shen jing wrote: >> 1. Pure ATM. In this case the switch will operate UNI and NNI interfaces, >> and will run PNNI as its routing protocol (PNNI is both an IGP and EGP). >> UNI and PNNI signalling will happen on VCI 5. > >I don't think this will happen in real world , because MPLS integrate >IP routing and switching mechanism. As it uses ATM switch as transit stage >solution, it has to use SIN style equipments. While, it will go to pure MPLS in >future. If PNNI is used as routing procedure, it should be the situation where >ATM switch path is used as tunnel for MPLS. > > >> >> 2. Pure MPLS. In this mode, there is no ATM signalling, and no PNNI. >> MPLS routing and signalling (OSPF, ISIS, CR-LDP, RSVP-TE, etc.) will pass >> over VCI 32 (note, please check the latest draft for the actual VCI number, >> it's a while since I read this info). >> >> 3. Ships in the Night (SIN). In this case, both ATM and MPLS Control >> Planes operate simultaneously. ATM signalling happens on VCI 5, and MPLS >> signalling on VCI 32. VCs that are set up as a result of signalling are >> "owned" by one or other of these control planes. SIN would allow an >> operator to continue to run high revenue voice services (and maybe existing >> Frame Relay or native ATM services...they make money too) over the ATM >> "character" of the switch. They can then run the loss-making Internet >> services over the MPLS character. >> >> I think there are ideas floating around about a more integrated control >> plane for ATM/MPLS switches based on PNNI, but I don't think these have >> made it to draft as yet. >> >> Cheers, >> Geoff >> >> At 10:02 18/04/01 +0200, MP LS wrote: >> >Hello all, >> > >> >I have some questions becasue something is verry strange to me. >> >I just assumed that ATM-LSRS used an IP routing protocol (IGP) just for >> >finding the topology of the network. >> > >> >But last i read an doccument and there they described that When you change >> >an ATM switch to an ATM-LSR it will use PNNI instead of a IGP for IP. Can >> >anyone make this clear for me?? >> > >> >Thanks a lot. >> > >> >Greetings, >> > >> >Niels Sitters. >> > >> > >> >_________________________________________________________________________ >> >Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. >> > >> >------- >> >The MPLS-OPS Mailing List >> >Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml >> >Archive: http://www.mplsrc.com/mpls-ops_archive.shtml >> > >> ================================================================ >> Geoff Bennett Tel: (33) 497 21 43 62 >> Director of Technology, OCTO Fax: (33) 497 21 43 50 >> Marconi >> Gaia - Bat. E email: geoff.bennett@marconi.com >> BP 123 >> 06903 SOPHIA ANTIPOLIS >> FRANCE >> ================================================================ > ================================================================ Geoff Bennett Tel: (33) 497 21 43 62 Director of Technology, OCTO Fax: (33) 497 21 43 50 Marconi Gaia - Bat. E email: geoff.bennett@marconi.com BP 123 06903 SOPHIA ANTIPOLIS FRANCE ================================================================
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