Traffic Monitoring

Design Guide

Note: The IEEE 802.1w protocol is enabled by default when running spanning tree in RPVST+ or MST mode on the Cisco Catalyst Blade Switch 3020. The Cisco Catalyst Blade Switch 3020 enables PVST+ for VLAN 1 by default.

The Spanning Tree Protocol uses the path cost value to determine the shortest distance to the root bridge. The port path cost value represents the media speed of the link and is configurable on a per-interface basis, including Cisco EtherChannel interfaces. To allow for more granular Spanning Tree Protocol calculations, enable the use of a 32-bit value instead of the default 16-bit value. The longer path cost better reflects changes in the speed of channels and allows the Spanning Tree Protocol to optimize the network in the presence of loops.

Note: The Cisco Catalyst Blade Switch 3020 supports IEEE 802.1t, which allows for spanning- tree calculations based on a 32-bit path cost value instead of the default 16 bits. For more information about the standards supported by the Cisco Catalyst Blade Switch 3020, refer to the Cisco Catalyst Blade Switch 3020 Overview document: http://www.cisco.com/go/bladeswitch.

For more information regarding spanning tree and Layer 2 design in the data center, visit: http://www.cisco.com/en/US/solutions/ns340/ns517/ns224/ns304/net_design_guidance0900aecd80 0e4d2e.pdf.

Traffic Monitoring

The Cisco Catalyst Blade Switch 3020 supports the following traffic-monitoring features, which are useful for monitoring blade-enclosure traffic in data center environments:

●Switched Port Analyzer (SPAN)

●Remote SPAN (RSPAN)

SPAN mirrors traffic transmitted or received on source ports or source VLANs to another local switch port. This traffic can be analyzed by connecting a switch or Remote Monitoring (RMON) probe to the destination port of the mirrored traffic. Only traffic that enters or leaves source ports or source VLANs can be monitored using SPAN.

RSPAN facilitates remote monitoring of multiple switches across your network. The traffic for each RSPAN session is carried over a user-specified VLAN that is dedicated to that RSPAN session for all participating switches. The SPAN traffic from the source ports or source VLANs is copied to the RSPAN VLAN. This mirrored traffic is then forwarded over trunk ports to any destination session that is monitoring the RSPAN VLAN.

Figure 5 illustrates the use of RSPAN in a dual-blade switch environment. Here the internal cross- connects can allow the RSPAN traffic to traverse the backplane from one switch to the other. The second switch can either send the SPAN traffic out an uplink port to a local IDS device or pass it up the EtherChannel uplink to the aggregation switch above. Because RSPAN uses its own unique VLAN, it can use ports that may be blocked by other data VLANs.

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

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NAD 3020 manual Traffic Monitoring
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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.
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