3com S7906E 安装指导

下载
页码 2621
 
1-13 
z
 
Cooperation of RSVP-TE and BFD: BFD is a fast detection mechanism, which can detect faults of 
links or nodes timely. In this method, FRR can obtain the link status timely through BFD, so as to 
implement fast switchover of links. 
z
 
RSVP hello: In this method, RSVP hello is enabled on each protected node and its neighbor nodes 
along the primary LSP, so that a device periodically sends hello messages to its peer device on the 
LSP. If a link or node fails, hello messages will be lost. If a device cannot receive hello messages 
from its peer in three hello intervals, the hello mechanism concludes that a link failure occurs. 
Hence, the hello mechanism is slower in link failure detection, compared with the other two 
methods.  
DiffServ-Aware TE 
Diff-Serv is a model that provides differentiated QoS guarantees based on class of service. 
MPLS TE is a traffic engineering solution that focuses on optimizing network resources allocation. 
DiffServ-aware TE (DS-TE) combines them to optimize network resources allocation at a per-service 
class level. For traffic trunks which are distinguished by class of service, this means varied bandwidth 
constraints. 
Essentially, what DS-TE does is to map traffic trunks with LSPs, making each traffic trunk traverse the 
constraints-compliant path. 
DS-TE involves two concepts: 
z
 
Class type (CT): The set of traffic trunks crossing a link that is governed by a specific set of 
Bandwidth constraints. CT is used for purposes of link bandwidth allocation, constraint based 
routing, and admission control. A given traffic trunk belongs to the same CT on all links. 
z
 
Bandwidth constraints (BCs): Different BC models can be created to control CTs. A BC model is 
broken down into maximum number of BCs (MaxBC), and mappings between BCs and CTs. 
 
 
Currently, DiffServ-Aware TE is not supported. 
 
Protocols and Standards 
z
 
RFC 2702  Requirements for Traffic Engineering Over MPLS 
z
 
RFC 3212  Constraint-Based LSP Setup using LDP 
z
 
RFC 2205  Resource ReSerVation Protocol 
z
 
RFC 3209  RSVP-TE: Extensions to RSVP for LSP Tunnels 
z
 
RFC 2961  RSVP Refresh Overhead Reduction Extensions 
z
 
RFC 3564  Requirements for Support of Differentiated Service-aware MPLS Traffic Engineering 
MPLS TE Configuration Task List 
Complete the following tasks to configure MPLS TE: