Platform Redundancy - Avaya 8800 Planning And Engineering, Network Design

time). This implies that unless VLACP is enabled on the IST peer, the ports stay in a disabled
state. When VLACP is enabled at the IST peer, the VLACPDU is received and the ports are
reenabled. This behavior can be replicated despite the IST connectivity between the end-to-
end peers. When you enable VLACP on the IST ports at one end of the IST, the ports are
taken down along with the IST. However, the IST at the other end stays active until the expiry
timeout occurs on the other end. As soon you enable VLACP at the other end, the VLACPDU
is received by the peer and the ports are brought up at the software level.

Platform redundancy

Provide platform layer redundancy to ensure that faulty hardware does not cause a service
interruption.
Avaya recommends that you use the following mechanisms to achieve device-level redundancy:
• Redundant power supplies
Employ N + 1 power supply redundancy, where N is the number of required power supplies to
power the chassis and its modules. Connect the power supplies to an additional power supply
line to protect against supply problems.
To provide additional redundancy, you can use the 8005DI AC power supply, which is a dual
AC input, 1170/1492 watts (W) AC-DC power supply. On the 8005DI AC power supply, the two
AC input sources can be out of synchronization with each other, having a different voltage,
frequency, phase rotation, and phase angle as long as the power characteristics for each
separate input AC source remain within the range of the manufacturer's specifications.
The 8000 Series switch has two slots for fan trays or cooling modules, each with eight
individual fans. Sensors are used to monitor board health.
• Input/output (I/O) port redundancy
You can protect I/O ports using a link aggregation mechanism. MLT, which is compatible with
802.3ad static (Link Access Control Protocol [LACP] disabled), provides you with a load
sharing and failover mechanism to protect against module, port, fiber or complete link failures.
• Switch fabric redundancy
Avaya recommends that you use two SF/CPUs to protect against switch fabric failures. The
two SF/CPUs load share and provide backup for each other. Using the 8006 or 8010 chassis,
full switching capacity is available with both SF/CPU modules. With two SF/CPUs, you can use
High Availability mode. For more information about High Availability (HA) mode, see
Availability mode
• SF/CPU redundancy
The CPU is the control plane of the switch. It controls all learning, calculates routes, and
maintains port states. If the last SF/CPU in a system fails, the switch resets the I/O cards after
a heartbeat timeout period of 3 seconds.
To protect against CPU failures, Avaya has developed two different types of control plane
(CPU) protection:
- Warm Standby mode
June 2016
on page 62.
Planning and Engineering — Network Design
Comments on this document? infodev@avaya.com
Platform redundancy
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