P2MP Extensions to LDP V01
Document Sample


MPLS signaling extensions
for Upstream Label Assignment
draft-raggarwa-mpls-ldp-upstream-00.txt
draft-raggarwa-mpls-rsvp-upstream-00.txt
Rahul Aggarwal (Juniper Netwroks)
Jean-Louis Le Roux (France Telecom)
IETF 64, Vancouver, MPLS WG, 11/08/2005
Background (1)
Architecture for upstream label assignment is defined in
draft-raggarwa-mpls-upstream
MPLS Multicast encapsulation defined in
draft-rosen-mpls-multicast-encaps
If for a given FEC F, Ru is the upstream LSR and Rd the downstream LSR
Downstream Assigned label = The label is distributed by Rd to Ru
Upstream Assigned label = The label is distributed by Ru to Rd
Upstream assigned label are looked up in a context specific ILM
The context can be, e.g., the Upstream Neighbor or the tunnel over which MPLS
packets may be received
Various applications such as: Multicast VPN, avoiding branch LSR replication on
multipoint interfaces (LAN, IP Multicast tunnel), and P2MP MPLS Hierarchy
Background (2)
Extensions to MPLS signaling protocols are required to support upstream label
assignment
Need for a mechanism allowing an LSR to advertise to its neigbours whether it
supports upstream label assignment
Need for a mechanism to request & distribute upstream assigned labels
A P2MP LSP may be encapsulated in an IP Multicast tunnel or another P2MP
LSP =>This requires to signal the id of the underlying IP or MPLS tunnel
draft-raggarwa-mpls-ldp-upstream &
draft-raggarwa-mpls-rsvp-upstream
define respectively LDP and RSVP extensions to support these functions
This is a result of a split of draft-raggarwa-mpls-rsvp-ldp-upstream
that was presented in Paris
These are companion documents to the Upstream label assignment
Architecture and Encapsulation drafts
draft-raggarwa-mpls-ldp-upstream
Advertisement of Upstream Label assignment capability
Definition of a capability TLV, and Upstream Label Assignment sub-TLV to be
carried in the Initialization message
Request & Distribution of Upstream Assigned Labels
Definition of an Upstream Assigned Label Request TLV to be carried within a Label
Request message
Definition of an Upstream Assigned Label TLV to be carried within a Label
Mapping/Release/Withdraw message
A LDP P2MP LSP maybe tunneled in a RSVP-TE P2MP LSP
A new RSVP-TE P2MP tunnel sub-TLV is defined for the Interface ID TLV
It carries the P2MP session and sender objects of the outer RSVP-TE P2MP
tunnel
draft-raggarwa-mpls-rsvp-upstream
Advertisement of Upstream Label assignment capability
A new capability bit is defined in the CAPABILIY object carried in an Hello
message
Distribution of Upstream Assigned Labels
Definition of an UPSTREAM_ASSIGNED_LABEL object, to be carried within a
Path
A RSVP-TE P2MP LSP maybe tunneled in another RSVP-TE P2MP LSP
A new RSVP-TE P2MP tunnel TLV is defined for the IF_ID RSVP-HOP object
It carries the P2MP session and senders objects of the outer RSVP-TE P2MP LSP
Allow binding the inner and outer RSVP-TE P2MP LSPs
This mechanism extends LSP hierarchy to P2MP LSPs
draft-raggarwa-mpls-rsvp-upstream
RSVP-TE P2MP LSPs on LAN interfaces
RSVP-TE P2MP LSP
From R1 to {L1, L2) Resv
Path
Lbl 40 L1
Path
Resv R2
Resv UAL 25
Path 25 40
Lbl 18B1 B1 ILM to NHLFE
R1 25-> if 2, lbl 40
18 25 Resv
ILM-to-NHLFE Resv
Path
Path 25
18-> if 2, lbl 25 R3 Lbl 33
UAL 25 33 L2
B1 ILM-to-NHLFE
25-> if 2, lbl 33
Upstream Label assignment allows a branch LSR to send a single copy
of a packet on a LAN interface of a P2MP LSP => bandwidth savings
Encapsulation follows procedure in draft-rosen-mpls-multicast-encaps
Next steps
Straightforward LDP and RSVP-TE extensions for
Upstream Label Assignment
Allows for efficient support of multipoint interfaces
and P2MP Hierarchy
Need for WG feedback
WG doc?
Thanks
Questions?
Get documents about "