Scalability

Design Guide

●Network Fault Tolerance (NFT)

●Transmit Load Balancing (TLB)

●Switch Assisted Load Balancing (server load balancing [SLB])

NFT teaming creates a virtual interface by grouping the blade-server network adapters into a team. One adapter is the primary active interface and all other adapters are in a standby state. The virtual adapter uses a single MAC address and a single Layer 3 address. NFT provides adapter fault tolerance by monitoring the state of each team member’s network connection. The standby NICs become active only if the primary NIC loses connectivity to the network.

TLB teaming supports adapter fault tolerance (NFT) and adds more functions in the server for load balancing egress (transmit) traffic across the team. Note that a TLB team uses only one NIC to receive traffic. The load-balancing algorithm is based on either the destination MAC or IP address. This teaming method provides better use of the bandwidth available for egress traffic in the network than NFT.

SLB teaming extends the functions of TLB by allowing the team to receive load-balanced traffic from the network. This reception requires that the switch can load balance the traffic across the ports connected to the server NIC team. The Cisco Catalyst Blade Switch 3020 supports the IEEE 802.3ad standard and Gigabit Ethernet port channels. SLB teaming can only be used on full-height servers, because it requires that both NICS go to the same upstream switch.

For more information about NIC teaming, please visit: http://h18000.www1.hp.com/products/servers/networking/whitepapers.html.

Scalability

The capability of the data center to adapt to increased demands without compromising its availability is a crucial design consideration. The aggregation layer infrastructure and the services it provides must accommodate future growth in the number of servers or subnets it supports.

When deploying blade servers in the data center, two primary factors need to be considered:

●Number of physical ports in the aggregation and access layers

●Number of slots in the aggregation layer switches

Physical Port Count

The introduction of blade systems into the data center requires greater port density at the aggregation layer. Blade systems, deployed with internal switches, provide their own access layer. The cabling and maximum number of servers per enclosure are predetermined. Scaling the aggregation layer ports to accommodate the blade-system uplinks is an area that requires attention.

It is important to remember that aggregation switches provide data center services such as load balancing, security, and network analysis that may require dedicated ports for appliances or slots for integrated services. This situation directly affects the number of ports available for access layer connectivity.

© 2008 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.

Page 14 of 28

Page 13 Page 15
Page 14
Image 14
NAD 3020 manual Scalability, Physical Port Count
Page 13 Page 15

3020 specifications

The NAD 3020 is a classic integrated amplifier that has gained a legendary status among audiophiles since its launch in 1978. Known for its incredible sound quality and value for money, the NAD 3020 has become a reference point in the realm of affordable audio equipment.

One of the main features of the NAD 3020 is its high current design, allowing it to drive a wide range of speaker impedances. This capability ensures that the amplifier can deliver a dynamic sound, characterized by a robust bass response and clear treble. With a power output of 20 watts per channel into 8 ohms, the NAD 3020 is often underestimated due to its modest specifications. However, it can produce remarkable sound pressure levels and handle transient peaks with ease.

The amplifier utilizes a simplified circuit design, which is one of its defining characteristics. This minimalist approach reduces potential signal distortion, enabling the amplifier to maintain sonic integrity. The use of discrete components rather than integrated circuits contributes to its rich, detailed audio reproduction, making it a favorite among purists.

Another key technology featured in the NAD 3020 is its unique power supply design. NAD engineers incorporated a toroidal transformer, which is known for its compact size and low electromagnetic interference. This results in cleaner power delivery, which is essential for maintaining audio clarity and depth.

The NAD 3020 is also equipped with multiple inputs, including phono, line-level, and tape inputs, making it versatile for various audio sources. The built-in phono stage supports moving magnet cartridges, allowing vinyl enthusiasts to connect their turntables directly to the amplifier without needing a separate phono preamplifier.

In terms of build quality, the NAD 3020 features a sturdy chassis that minimizes vibrations, ensuring that audio performance remains stable. The user-friendly design includes a straightforward control layout, allowing users to adjust volume and tone settings with ease.

Throughout its decades-long legacy, the NAD 3020 has influenced countless audio products and remains a benchmark for entry-level amplification. Its combination of power, clarity, and affordability makes it a beloved choice for both new listeners and seasoned audiophiles seeking a dependable amplifier that doesn't compromise on sound quality. The NAD 3020 exemplifies how great engineering can lead to remarkable audio experiences, solidifying its place in the history of hi-fi audio.
Top Page Image Contents