Administrative group and affinity attribute, Reoptimization, Rsvp-te – H3C Technologies H3C S7500E Series Switches User Manual
Page 87: Overview, Basic concepts of rsvp-te
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available. If this is undesirable, the network administrator can set up the CR-LSP using route
underpinning to make it a permanent path.
Administrative group and affinity attribute
The affinity attribute of an MPLS TE tunnel identifies the properties of the links that the tunnel can use.
Together with the link administrative group, it decides which links the MPLS TE tunnel can use.
Reoptimization
Traffic engineering is a process of allocating/reallocating network resources. You may configure it to
meet desired QoS.
Normally, service providers use some mechanism to optimize CR-LSPs for best use of network
resources. They can do this manually but CR-LSP measurement and tuning are required. Alternatively,
they can use MPLS TE where CR-LSPs are dynamically optimized.
Dynamic CR-LSP optimization involves periodic calculation of paths that traffic trunks should traverse.
If a better route is found for an existing CR-LSP, a new CR-LSP will be established to replace the old
one, and services will be switched to the new CR-LSP.
RSVP-TE
This section covers these topics:
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Overview
Currently, two QoS models are available: Integrated Service (IntServ) and Differentiated Service
(DiffServ).
Resource Reservation Protocol (RSVP) is designed for IntServ. It reserves resources on each node
along a path. RSVP operates at the transport layer but does not participate in data transmission. It is
an Internet control protocol similar to ICMP.
The following are features of RSVP:
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Unidirectional
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Receiver oriented. The receiver initiates resource reservation requests and is responsible for
maintaining the reservation information.
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Using soft state mechanism to maintain resource reservation information.
Extended RSVP can support MPLS label distribution and allow resource reservation information to be
transmitted with label bindings. This extended RSVP is called RSVP-TE, which is operating as a
signaling protocol for LSP tunnel setup in MPLS TE.
Basic concepts of RSVP-TE
1) Soft
state