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What is Flex LSP?

What is Flex LSP?

Flex LSP also known as Associated Bidirectional LSPs is the combination of static bidirectional MPLS-TP and dynamic MPLS-TE. Flex LSP provides bidirectional label switched paths (LSPs) set up dynamically through Resource Reservation Protocol–Traffic Engineering (RSVP-TE). It does not support non-co routed LSPs.

Is LSP a tunnel?

This network configuration example provides an overview of a Resource Reservation Protocol (RSVP) label-switched path (LSP) tunnel that enables you to send RSVP LSPs inside other RSVP LSPs. This enables a network administrator to provide traffic engineering from one end of the network to the other.

What is traffic engineering in MPLS?

MPLS traffic engineering allows network operators to assign a bandwidth value to each link. The assigned bandwidth usually equals to the physical bandwidth of the link. MPLS traffic engineering also allows the assignment of a bandwidth value to each MPLS tunnel.

Why do we need link state protocols in MPLS TE?

Link-state protocols (IS-IS and OSPF) provide the flooding capabilities that are required to distribute these attributes. LSRs use this information to build a TE topology database. This database is separate from the regular topology database that LSRs build for hop-by-hop destination based routing.

What is MPLS LSP?

LSP—A label switched path (LSP) is a path through an MPLS network, set up by a signaling protocol, such as LDP, RSVP TE, BGP or CR-LDP.

How much overhead does an MPLS LSP tunnel have?

How much overhead does an MPLS LSP tunnel have? A. An MPLS LSP tunnel has one label (four bytes) or two labels (for example, when using Link Protection Fast reroute) of overhead. Unlike GRE tunnel, MPLS doesn’t change the IP header.

What is LDP and RSVP?

LDP over RSVP Using OSPF as IGP. This section provides information about Label Distribution protocol (LDP) over Resource Reservation Protocol for Traffic Engineering (RSVP-TE), also called LDPoRSVP, that uses RSVP Label Switched Paths (LSPs) as a transport vehicle to carry the packets using LDP LSPs.

Why IGP is used in MPLS?

The MPLS LDP IGP Synchronization feature ensures that the Label Distribution Protocol (LDP) is fully established before the Interior Gateway Protocol (IGP) path is used for switching. Your software release may not support all the features documented in this module.

Can MPLS work without LDP?

It’s perfectly possible to have a full-mesh of MPLS TE tunnels in network core and run LDP over them; MPLS TE tunnels can fail.

How a LSP is formed in MPLS?

LSP is created in two ways in IP/MPLS over MPLS-TP. One way is to create MPLS-TP LSP, and notify the IP/MPLS network in FA (forwarding adjacent) mode. When IP/MPLS LSP is created, the created TP LSP can be considered as a direct link to participate in the routing.

What does LSP stand for in networking?

Short for link state packet, LSP is a packet of information generated by a network router in a link state routing protocol that lists the router’s neighbors.

What is the difference between MPLS and LDP?

2 commonly used terms in MPLS are LDP and RSVP-TE. While the former relates to easy provisioning in MPLS setup, the latter i.e. RSVP-TE is related to guarantee bandwidth for traffic communication. LDP setups LSPs based on routing data, whereas RSVP setups additional traffic engineered LSPs.

What is MPLS LDP?

Label Distribution Protocol (LDP) is a protocol in which routers capable of Multiprotocol Label Switching (MPLS) exchange label mapping information. Two routers with an established session are called LDP peers and the exchange of information is bi-directional.

Why an IGP is required?

The IGP is used to establish the BGP session (TCP session) and to resolve the BGP next hop. eBGP, on the other hand, is generally configured using the directly connected interface address.

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