The MPLS WG Archive

[Pramoda Nallur <Pramoda.Nallur@ind.alcatel.com>]

Hi Prosenjit,


> Hi Pramoda,
>
>    You can aggregate two RSVP microflows and share the
> same LSP for both dataflow by selecting appropriate
> reservation style. But for signaling, RSVP PATH message
> needs to be processed at each hop in the path and needs
> to go to RSVP module at each node. Same is the story with
> RSVP RESV message. So why do you want to use an LSP to
> send PATH and RESV message, in the given topology?
>

Agreed that you can aggregate the two dataflows onto the same LSP, based on
the reservation style.
The point was that if the RSVP PATH/RESV messages (for the microflow) are
processed at each hop along the path, you could be reserving resources
twice - once when you set up the LSP and again due to the microflow
RSVP messages.
(Note that the reservations for the LSP would anyway be periodically
refreshed by the ingress LER1.)

- Pramoda.

>
> Thanks,
> Prosenjit Pal
>
> -----Original Message-----
> From: Pramoda Nallur
> To: Jahaapanah Alampanah
> Cc: mpls@UU.NET
> Sent: 7/25/00 9:12 AM
> Subject: Re: Reg. MPLS-RSVP LSP Tunnels...
>
> Jah,
>
> Jahaapanah Alampanah wrote:
>
> > Hi Jie,
> >
> > If I understand Nallur's problem statement
> > correctly, its got to do with aggregation
> > of RSVP micro flows into LSP Tunnels
> > setup by MPLS-RSVP.
> >
> >
> > An RSVP-LSP-Tunnel has already been established
> > between LER1 and LER2. Now a micro-flow RSVP
> > PATH message from S arrives at LER1. We want
> > this micro-flow to take the LSP. So if we just
> > tunnel this PATH message into the LSP, and
> > make it reach end-host R, the problem is
> > how do we transport the RESV message from R
> > back to S through the same LSP since this
> > is uni-directional?
> >
>
> You are right in your understanding. But, the question is, should the
> micro-flow PATH message
> be tunelled into the LSP at all ?
>
> - Pramoda.
>
> >
> > I hope Nallur agrees with this re-statement!
> >
> > All comments are welcome.
> >
> > -Jah
> >
> > -----Original Message-----
> > From: Jie Zou <jzou@mars.iol.unh.edu>
> > To: Pramoda Nallur <Pramoda.Nallur@ind.alcatel.com>
> > Cc: mpls@UU.NET <mpls@UU.NET>; Dilip.Pandit@ind.alcatel.com
> > <Dilip.Pandit@ind.alcatel.com>; Kishore Rao <kishore>;
> > Manu.Prakash@ind.alcatel.com <Manu.Prakash@ind.alcatel.com>
> > Date: Tuesday, July 25, 2000 6:49 PM
> > Subject: Re: Reg. MPLS-RSVP LSP Tunnels...
> >
> > >
> > >I hope the following can answer a part of questions.
> > >
> > >According the darft, if A or B is a non-RSVP router, it can't convey
> > >labels via RSVP path. And it's neighber who knows it's non-RSVP
> > >router should send a PathErr back to the sender.
> > >
> > >If A or B is an RSVP router but doesn't recognize the LRO, it should
> > >send a PathErr toward the sender.
> > >
> > >If A or B is an RSVP router and recognize the LRO but not C_TYPE also
> > >sends a PathErr toward the sender.
> > >
> > >Else the Path msg should pass A and B toward the receiver and
> > >vice verse the Resv msg should pass the B and A toward the sender.
> > >
> > >
> > >Regards,
> > >
> > >-----------------------------------------------------
> > >Jie Zou (603)862-4212(Office)
> > >MPLS Consortium
> > >IOL, UNH (603)868-2983(Home)
> > >-----------------------------------------------------
> > >
> > >On Tue, 25 Jul 2000, Pramoda Nallur wrote:
> > >
> > >> Hi,
> > >>
> > >> I have a query on setting up RSVP MPLS LSPs in an ATM network.
> > >> [ Topology Driven LSP Setup Scenario ]
> > >>
> > >> Suppose the network configuration is as follows :
> > >>
> > >>     S--A--LER1---LSR---LER2--B--R
> > >>
> > >> where,
> > >>     S                   --> Sender(RSVP aware)
> > >>     R                   --> Receiver(RSVP aware)
> > >>     A, B                --> Legacy IP Routers
> > >>     LER1, LER2 and LSR  --> MPLS-RSVP ATM switches.
> > >>
> > >> An LSP setup is initiated from LER1 with FEC=(S,R).
> > >>
> > >> The RSVP-TE PATH msg (with Sender=S, Session = Sess_R) creates an
> > >> RSVP Session, Sess_R at LER1, LSR and LER2. The Egress LER2
> responds with
> > a
> > >>
> > >> RSVP-TE RESV msg reserving resources and sets up an LSP via LSR to
> LER1.
> > >>
> > >> After the LSP is setup, the RSVP-TE PATH msgs from LER1 and RSVP-TE
> RESV
> > >> msgs
> > >> from LER2 periodically refresh the RSVP reservation state on all
> nodes
> > >> along the LSP.
> > >>
> > >> Suppose, Sender S sends an RSVP PATH msg to R (with Session =
> Sess_R).
> > >>
> > >>  1. Will this PATH msg take the unlabelled path OR will it get
> switched
> > >> onto the LSP at LER1 ?
> > >>
> > >>  2. Also, how are the resulting RESV msgs from R propagated back to
> S ?
> > >>
> > >>  3. If these PATH and RESV msgs take the unlabelled path, will this
> result
> > >> in
> > >>     resource allocation again along all nodes traversed by the LSP
> ?
> > >>
> > >>
> > >> The "RSVP-TE: Extensions to RSVP for LSP Tunnels"
> > >> (draft-ietf-mpls-rsvp-lsp-tunnel-06.txt)
> > >> does not mention how the above should be handled.
> > >>
> > >> Any comments on this ?
> > >>
> > >> - Pramoda Nallur
> > >>