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Re: MPLS - ATM interworking?

  • From: CATANZARITI Sergio FTR&D/TI <sergio.catanzariti@rd.francetelecom.com>
  • Date: Wed, 31 May 2000 13:01:23 -0700
  • Cc: mpls@UU.NET, "'Andrzej Czerczak'" <Andrzej_Czerczak/HeadQ@netia.pl>, rraszuk@cisco.com

Title: RE: Re: MPLS - ATM interworking?

Thanks, I knew that RFC. But, it does not solve the original question that was ECN application in an MPLS network and its usage.

Sergio

    --------------------------------------------------------------------
    Sergio Catanzariti
    Senior Project Manager, Technology Integration
    France Telecom R&D
    1000 Marina Boulevard Suite 300
    Brisbane CA 94005
    Tel. 650-875-1526
    Fax. 650-875-1505
    email:sergio.catanzariti@rd.francetelecom.com
    --------------------------------------------------------------------


    -----Original Message-----
    From:   Shahram Davari [SMTP:Shahram_Davari@pmc-sierra.com]
    Sent:   Wednesday, May 31, 2000 12:50 PM
    To:     'CATANZARITI Sergio FTR&D/TI'; Shahram Davari
    Cc:     mpls@UU.NET; 'Andrzej Czerczak'; rraszuk@cisco.com
    Subject:        RE: Re: MPLS - ATM interworking?

    Hi,
     
    1) Please check RFC 2481 for the definition and usage of ECN.
    2) As far as I know there is currently no proposal to use ECN bits in an
    Edge-to-Edge level. The intention of Sally Floyd's draft was that ECN to be
    used with TCP (end-to-end).
     
    Regards,
    Shahram

    -----Original Message-----
    From: CATANZARITI Sergio FTR&D/TI
    [mailto:sergio.catanzariti@rd.francetelecom.com]
    Sent: Wednesday, May 31, 2000 3:13 PM
    To: 'Shahram Davari'
    Cc: mpls@UU.NET; 'Andrzej Czerczak'; rraszuk@cisco.com
    Subject: RE: Re: MPLS - ATM interworking?



    Shahram,

            the draft-ietf-mpls-ecn-00.txt does not say anything about ECN usage
    and applications, but only about ECN support and definition in an MPLS
    network, the things are quite different. So, I have the same question: where
    I can find Ramakrishnan et al., "A Proposal to Incorporate ECN in MPLS",
    draft-ietf-mpls-ecn-00.txt?

            Also, I do believe that the ECN in an MPLS network works on resource
    types (LSPs) quite different than native IP flows. So, the source address is
    not that useful here, albeit in an ECN schema in pure IP networks.

            ECN in an MPLS network is supposed to signal congestion in an
    edge-to-edge fashion (different from end-to-end) where the LERs could
    cooperate on that.

            Absolutely, I want to associate LSPs with congestion dynamics to
    eventually slow them down. How can I do that? That's the question.

    Sergio

            --------------------------------------------------------------------

    Sergio Catanzariti
    Senior Project Manager, Technology Integration
    France Telecom R&D
    1000 Marina Boulevard Suite 300
    Brisbane CA 94005
    Tel. 650-875-1526
    Fax. 650-875-1505
    email:sergio.catanzariti@rd.francetelecom.com
    --------------------------------------------------------------------


            -----Original Message-----
    From:   Shahram Davari [SMTP:Shahram_Davari@pmc-sierra.com]
    Sent:   Wednesday, May 31, 2000 11:34 AM
    To:     'Andrzej Czerczak'; rraszuk@cisco.com
    Cc:     mpls@UU.NET
    Subject:        RE: Re: MPLS - ATM interworking?

            Andrzej,

            1)ECN usage is defined in draft-ietf-mpls-ecn-00.txt, which is
    attached to
    this email.

            2)Congestion Notification is and end-to-end signal which is meant to
    be used
    by TCP. You don't need to know the ingress LSR or even the LSP from which
    the congested packet is received. The receiver may send the congestion
    notification to the sender using source IP address, either through another
    LSP or even through normal IP hop-by-hop routing.

            Regards,
    -Shahram




            >-----Original Message-----
    >From: Andrzej Czerczak [ mailto:Andrzej_Czerczak/HeadQ@netia.pl
    <mailto:Andrzej_Czerczak/HeadQ@netia.pl> ]
    >Sent: Wednesday, May 31, 2000 1:46 PM
    >To: rraszuk@cisco.com
    >Cc: mpls@UU.NET
    >Subject: Re:Re: MPLS - ATM interworking?
    >
    >
    >
    >Robert,
    >First of all thanks for your comments.
    >
    >>Have you read draft MPLS Support of Differentiated Services
    >>draft-ietf-mpls-diff-ext-04.txt where we are proposing to use the ECN
    >>(explicit congestion notification) on a per LSP basis using
    >the EXP bits
    >>in the shim header ? Currently this is the most attractive
    >option, but I
    >> am not aware of any implementation support this today.
    >
    >
    >
    >a) Document draft-ietf-mpls-diff-ext-04.txt does not not
    >define the usage
    >of ECN.
    >
    >b) Taking into account label merging capabilites of LSRs, how
    >can determine
    >to which ingress LSP to to send Congestion Notification?
    >
    >c) Where can I find:
    >
    >Ramakrishnan et al., "A Proposal to Incorporate ECN in
    >   MPLS", draft-ietf-mpls-ecn-00.txt?

            >
    >
    >
    >What I'd like to say is, that at least during first phases of
    >implementations (before entire infrastructure will become IP)
    >interworking
    >of MPLS core and ATM edge will be important, but I could not find a
    >proposal of how to do interworking between them.
    >
    >
    >
    >Andrzej
    >
    >
    >
    >
    >
    >
     << File: draft-mpls-ecn-00.txt >>