The MPLS WG Archive

[Jie Zou <jzou@mars.iol.unh.edu>]

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
>