High Availability Technologies; Fault Detection Technologies - HPE FlexNetwork HSR6800 series Configuration Manual

High availability technologies

Increasing MTBF or decreasing MTTR can enhance the availability of a network. The high
availability technologies described in this section meet the level 2 and level 3 high availability
requirements in the aspect of decreasing MTTR.
High availability technologies can be classified as fault detection technologies or protection
switchover technologies.

Fault detection technologies

Fault detection technologies enable detection and diagnosis of network faults:
•
CFD, DLDP, and Ethernet OAM are data link layer fault detection technologies.
•
BFD is a generic fault detection technology that can be used at any layer.
•
NQA is used for diagnosis and evaluation of network quality.
•
Track works along with other high availability technologies to detect faults through a
collaboration mechanism.
Table 2 Fault detection technologies
Technology
CFD
DLDP
Ethernet OAM
BFD
NQA
Track
Introduction
CFD, which conforms to IEEE 802.1ag CFM and ITU-T Y.1731, is
an end-to-end per-VLAN link layer OAM mechanism used for link
connectivity detection, fault verification, and fault location.
DLDP deals with unidirectional links that might occur in a network.
When detecting a unidirectional link, DLDP, as configured, can shut
down the related port automatically or prompt users to take actions
to avoid network problems.
As a tool monitoring Layer 2 link status, Ethernet OAM is mainly
used to address common link-related issues on the last mile. You
can monitor the status of the point-to-point link between two directly
connected devices by enabling Ethernet OAM on the two devices.
BFD provides a single mechanism to quickly detect and monitor the
connectivity of links or IP forwarding in networks. To improve
network performance, devices must quickly detect communication
failures to restore communication through backup paths as soon as
possible.
NQA analyzes network performance, services and service quality
through sending test packets, and provides you with network
performance and service quality parameters such as jitter, TCP
connection delay, FTP connection delay and file transfer rate.
The Track module implements collaboration between different
modules. The collaboration involves three sets of modules:
application, Track, and detection. These modules collaborate with
one another through collaboration entries. The detection modules
trigger the application modules to perform certain operations
through the Track module. The detection modules probe such items
as link status and network performance, and inform the application
modules of the detection result through the Track module. Once
notified of network status changes, the application modules use the
changes to avoid communication interruption and network
performance degradation.
2
Reference
"Configuring CFD"
"Configuring
DLDP"
"Configuring
Ethernet OAM"
"Configuring BFD"
Network
Management and
Monitoring
Configuration
Guide
"Configuring
Track"