H3C Technologies H3C SR8800 - Manual (Page 12)

3
Protection switchover technologies
Protection switchover technologies aim at recovering network faults. They back up hardware, link, routing,
and service information for switchover in case of network failures to ensure continuity of network services.
Table 3 Protection switchover technologies
Technology Introduction Reference
Active and
Standby
Switchover
Devices supporting active and standby switchover are normally
equipped with two main processing units (MPUs), with one being
the active MPU, and the other being the standby MPU. The
configurations on the standby MPU are the same as those on the
active MPU. When the active MPU fails or is plugged out, the
standby MPU automatically becomes the active MPU to ensure
non-stop operation of the devices.
Chapter “Configuring
active and standby
switchover”
Link
Aggregation
Link aggregation aggregates multiple physical Ethernet links into
one logical link to increase link bandwidth beyond the limits of any
one single link. This logical link is called an aggregate link. It
allows for link redundancy because the member physical links can
dynamically back up one another.
Layer 2—LAN
Switching
Configuration Guide
Smart Link
Smart Link is a feature developed to address the slow convergence
issue with STP. It provides link redundancy as well as fast
convergence in a dual uplink network, allowing the backup link to
take over quickly when the primary link fails.
Chapter “Configuring
Smart Link”
MSTP
As a Layer 2 management protocol, the Multiple Spanning Tree
Protocol (MSTP) eliminates Layer 2 loops by selectively blocking
redundant links in a network, and in the mean time, allows for link
redundancy.
Layer 2—LAN
Switching
Configuration Guide
RPR
Resilient Packet Ring (RPR) is a new MAC layer protocol designed
for transferring mass data services over MANs. It can operate on
synchronous optical network/synchronous digital hierarchy
(SONET/SDH), Dense Wavelength Division Multiplexing (DWDM)
and Ethernet to provide flexible and efficient networking schemes
for broadband IP MANs carriers.
Chapter “Configuring
RPR”
FRR
Fast Reroute (FRR) provides a quick per-link or per-node protection
on an LSP. In this approach, once a link or node fails on a path, FRR
comes up to reroute the path to a new link or node to bypass the
failed link or node. This can happen as fast as 50 milliseconds thus
minimizing data loss. Protocols such as RIP, OSPF, IS-IS, static
routing, and RSVP-TE support this technology.
Layer 3—IP Routing
Configuration Guide,
MPLS Configuration
Guide/Configuration
guide of the
corresponding
protocols
GR
Graceful Restart (GR) ensures the continuity of packet forwarding
when a protocol, such as BFP, IS-IS, OSPF, LDP, or RSVP-TE, restarts
or during an active/standby switchover process. It needs other
devices to implement routing information backup and recovery.
Layer 3—IP Routing
Configuration Guide,
MPLS Configuration
Guide/Configuration
guide of the
corresponding
protocols
VRRP
Virtual Router Redundancy Protocol (VRRP) is an error-tolerant
protocol, which provides highly reliable default links on multicast
and broadcast LANs such as Ethernet, avoiding network
interruption due to failure of a single link.
Chapter “Configuring
VRRP”