[PPP] MPLS, Multi-Protocol Label Switching
Protocol suite: | PPP, TCP/IP. |
Type: | Network layer protocol. |
Ethertypes: | 0x8847 unicast; 0x8848 multicast. |
PPP protocol: | 0x281, 0x283. |
MIME subtype: | iso.org.dod.internet.mgmt.mib-2.transmission.mplsStdMIB (1.3.6.1.2.1.10.166). |
Working groups: | mpls, Multiprotocol Label Switching. tewg, Internet Traffic Engineering. |
RFC 3469:
MPLS integrates the label swapping forwarding paradigm with network layer routing. To deliver reliable service, MPLS requires a set of procedures to provide protection of the traffic carried on different paths. This requires that the LSRs support fault detection, fault notification, and fault recovery mechanisms, and that MPLS signaling support the configuration of recovery.
Label entry. 32 bits.
(RFC 3031). A short fixed length physically contiguous identifier which is used to identify a FEC, usually of local significance.
00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Label | Exp | S | TTL |
Label. 20 bits.
Exp, experimental. 3 bits.
S, bottom of stack. 1 bit.
Set to one for the last entry in the label stack (i.e., for the bottom of the stack) and cleared to zero for all other label stack entries.
TTL, Time to Live. 8 bits.
FEC, Forwarding Equivalence Class.
(RFC 3031) Aa group of IP packets which are forwarded in the same manner (e.g., over the same path, with the same forwarding treatment).
frame merge.
(RFC 3031) Label merging, when it is applied to operation over frame based media, so that the potential problem of cell interleave is not an issue.
GMPLS, Generalized Multi-Protocol Label Switching.
Generalized MPLS extends the MPLS control plane to encompass time-division (e.g., Synchronous Optical Network and Synchronous Digital Hierarchy, SONET/SDH), wavelength (optical lambdas) and spatial switching (e.g., incoming port or fiber to outgoing port or fiber).
label merging.
(RFC 3031) The replacement of multiple incoming labels for a particular FEC with a single outgoing label.
label stack.
(RFC 3031) An ordered set of labels.
label swap.
(RFC 3031) The basic forwarding operation consisting of looking up an incoming label to determine the outgoing label, encapsulation, port, and other data handling information.
label swapping.
(RFC 3031) A forwarding paradigm allowing streamlined forwarding of data by using labels to identify classes of data packets which are treated indistinguishably when forwarding.
label switched hop.
(RFC 3031) The hop between two MPLS nodes, on which forwarding is done using labels.
loop detection.
(RFC 3031) A method of dealing with loops in which loops are allowed to be set up, and data may be transmitted over the loop, but the loop is later detected.
loop prevention.
(RFC 3031) A method of dealing with loops in which data is never transmitted over a loop.
LSP, label switched path.
(RFC 3031) The path through one or more LSRs at one level of the hierarchy followed by a packets in a particular FEC.
LSR, label switching router.
(RFC 3031) An MPLS node which is capable of forwarding native L3 packets.
merge point.
(RFC 3031) A node at which label merging is done.
MPLS domain.
(RFC 3031) A contiguous set of nodes which operate MPLS routing and forwarding and which are also in one Routing or Administrative Domain.
MPLS edge node.
(RFC 3031) An MPLS node that connects an MPLS domain with a node which is outside of the domain, either because it does not run MPLS, and/or because it is in a different domain. Note that if an LSR has a neighboring host which is not running MPLS, that that LSR is an MPLS edge node.
MPLS egress node.
(RFC 3031) An MPLS edge node in its role in handling traffic as it leaves an MPLS domain.
MPLS ingress node.
(RFC 3031) An MPLS edge node in its role in handling traffic as it enters an MPLS domain.
MPLS label.
(RFC 3031) A label which is carried in a packet header, and which represents the packet's FEC.
MPLS node.
(RFC 3031) A node which is running MPLS. An MPLS node will be aware of MPLS control protocols, will operate one or more layer 3 routing protocols, and will be capable of forwarding packets based on labels. An MPLS node may optionally be also capable of forwarding native layer 3 packets.
VC merge.
(RFC 3031) Label merging where the MPLS label is carried in the ATM VCI field (or combined VPI/VCI field), so as to allow multiple VCs to merge into one single VC.
VP merge.
(RFC 3031) Label merging where the MPLS label is carried din the ATM VPI field, so as to allow multiple VPs to be merged into one single VP. In this case two cells would have the same VCI value only if they originated from the same node. This allows cells from different sources to be distinguished via the VCI.
VPI/VCI.
(RFC 3031) A label used in ATM networks to identify circuits.
RFCs:
[RFC 2547] BGP/MPLS VPNs.
[RFC 2702] Requirements for Traffic Engineering Over MPLS.
[RFC 2917] A Core MPLS IP VPN Architecture.
[RFC 3031] Multiprotocol Label Switching Architecture.
[RFC 3032] MPLS Label Stack Encoding.
[RFC 3034] Use of Label Switching on Frame Relay Networks Specification.
[RFC 3035] MPLS using LDP and ATM VC Switching.
[RFC 3036] LDP Specification.
[RFC 3063] MPLS Loop Prevention Mechanism.
[RFC 3107] Carrying Label Information in BGP-4.
[RFC 3270] Multi-Protocol Label Switching (MPLS) Support of Differentiated Services.
[RFC 3353] Overview of IP Multicast in a Multi-Protocol Label Switching (MPLS) Environment.
[RFC 3429] Assignment of the 'OAM Alert Label' for Multiprotocol Label Switching Architecture (MPLS) Operation and Maintenance (OAM) Functions.
[RFC 3443] Time To Live (TTL) Processing in Multi-Protocol Label Switching (MPLS) Networks.
- Updates: RFC 3032.
[RFC 3468] The Multiprotocol Label Switching (MPLS) Working Group decision on MPLS signaling protocols.
[RFC 3469] Framework for Multi-Protocol Label Switching (MPLS)-based Recovery.
[RFC 3471] Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description.
[RFC 3472] Generalized Multi-Protocol Label Switching (GMPLS) Signaling Constraint-based Routed Label Distribution Protocol (CR-LDP) Extensions.
[RFC 3473] Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions.
- Updated by: RFC 4003.
[RFC 3477] Signalling Unnumbered Links in Resource ReSerVation Protocol - Traffic Engineering (RSVP-TE).
[RFC 3564] Requirements for Support of Differentiated Services-aware MPLS Traffic Engineering.
[RFC 3811] Definitions of Textual Conventions (TCs) for Multiprotocol Label Switching (MPLS) Management.
- iso.org.dod.internet.mgmt.mib-2.transmission.mplsStdMIB (1.3.6.1.2.1.10.166).
[RFC 3812] Multiprotocol Label Switching (MPLS) Traffic Engineering (TE) Management Information Base (MIB).
- iso.org.dod.internet.mgmt.mib-2.transmission.mplsStdMIB.MPLS-TE-STD-MIB (1.3.6.1.2.1.10.166.3).
[RFC 3813] Multiprotocol Label Switching (MPLS) Label Switching Router (LSR) Management Information Base (MIB).
- iso.org.dod.internet.mgmt.mib-2.transmission.mplsStdMIB.MPLS-LSR-STD-MIB (1.3.6.1.2.1.10.166.2).
[RFC 3814] Multiprotocol Label Switching (MPLS) Forwarding Equivalence Class To Next Hop Label Forwarding Entry (FEC-To-NHLFE) Management Information Base (MIB).
- iso.org.dod.internet.mgmt.mib-2.transmission.mplsStdMIB.MPLS-FTN-STD-MIB (1.3.6.1.2.1.10.166.8).
[RFC 3815] Definitions of Managed Objects for the Multiprotocol Label Switching (MPLS), Label Distribution Protocol (LDP).
- iso.org.dod.internet.mgmt.mib-2.transmission.mplsStdMIB.MPLS-LDP-STD-MIB (1.3.6.1.2.1.10.166.4).
- iso.org.dod.internet.mgmt.mib-2.transmission.mplsStdMIB.MPLS-LDP-ATM-STD-MIB (1.3.6.1.2.1.10.166.5).
- iso.org.dod.internet.mgmt.mib-2.transmission.mplsStdMIB.MPLS-LDP-FRAME-RELAY-STD-MIB (1.3.6.1.2.1.10.166.6).
- iso.org.dod.internet.mgmt.mib-2.transmission.mplsStdMIB.MPLS-LDP-GENERIC-STD-MIB (1.3.6.1.2.1.10.166.7).
[RFC 3919] Remote Network Monitoring (RMON) Protocol Identifiers for IPv6 and Multi Protocol Label Switching (MPLS).
[RFC 3945] Generalized Multi-Protocol Label Switching (GMPLS) Architecture.
[RFC 3946] Generalized Multi-Protocol Label Switching (GMPLS) Extensions for Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) Control.
- Defines CR-LDP TLV 0x0838 (SONET/SDH Traffic Parameters).
- Defines RSVP 0x0904 (SONET/SDH FLOWSPEC) and 0x0C04 (SONET/SDH SENDER_TSPEC).
[RFC 4003] GMPLS Signaling Procedure for Egress Control.
- Updates: RFC 3473.
[RFC 4023] Encapsulating MPLS in IP or Generic Routing Encapsulation (GRE).
- Defines IP protocol 137 (MPLS in IP).
[RFC 4105] Requirements for Inter-Area MPLS Traffic Engineering.
[RFC 4126] Max Allocation with Reservation Bandwidth Constraints Model for Diffserv-aware MPLS Traffic Engineering & Performance Comparisons.
[RFC 4127] Russian Dolls Bandwidth Constraints Model for Diffserv-aware MPLS Traffic Engineering.