Cabletron Systems NB25 E, NB20E user manual Bridge Filtering Method

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INTRODUCTION

according to the specific needs of a network manager. The network manager's ability to set up parameters within Remote LANVIEW ensures optimal performance for each bridge, and hence, each network. For example, a network manager can manage and monitor: the flow of traffic through a bridge, the status of a database, the bridge protocol and port parameters, and the bridge setup.

Both bridges also incorporate Cabletron Systems' LANVIEW Status Monitoring and Diagnostics Systems. Should a problem arise, LANVIEW's LEDs will help you to diagnose problems, such as power failures or cable faults. Individual or separate LEDs advise you that: the bridge is on line and operational, the bridge is receiving or transmitting data packets, or the bridge is detecting a collision signal from an individual segment.

The NB20E or NB25E Bridge interconnects networks consisting of Ethernet Version 1, Version 2, and/or IEEE 802.3 equipment. The bridge has two AUI ports so it can be connected directly to any of Cabletron’s many Ethernet transceivers for data transmission over various media including twisted pair, fiber optic, and/or thick or thin Ethernet coaxial cable.

1.4THE BRIDGE FILTERING METHOD

The Cabletron Systems NB20E and NB25E prevent unnecessary network traffic from passing through the bridge, by implementing a filtering process. This process begins with the creation of a list of local node addresses in a table referred to as the Source Address Table.

When the NB20E or NB25E first goes on line, the bridge initially forwards all packets through the bridge. As the bridge receives a packet, it learns the address of the sending node from the packet and stores that address in its Source Address Table, indicating the segment on which the address resides. In this manner, the bridge learns the address of each node on each side of the bridge and is able to use the addresses stored in the table to compare the destination address of each subsequent packet that travels to the bridge. If the destination address of a packet is located on the same segment (local segment) as the sending node, the packet is not forwarded across the bridge.

Figure 1-1 provides an illustration of the filtering process.

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Contents TWO Port Ethernet Bridges USER’S Manual Page Page FCC Notice Contents Contents Chapter Introduction Using this ManualNB20E and NB25E TWO Port Ethernet Bridge Getting HelpProvides an illustration of the filtering process Bridge Filtering MethodBridging Method Root Bridge Multiple Bridge EnvironmentsMultiple Bridging Environments Primary and Redundant Data PathsRemote Lanview Related Manuals Chapter Installation Requirements Specifications Location RequirementsNetwork Requirements General Operating SpecificationsNB20E NB25E PerformanceFront Panel Switches Front Panel IndicatorsRS232 Port AUI Port NB20E/NB25EEnvironmental Requirements Power Supply RequirementsSafety ServicePhysical Properties Chapter Installing the NB20E or NB25E Bridge Installing the BridgeUnpacking the NB20E or NB25E Bridge Rack Mount Brackets Installation Installing the Rack Mount BracketsConnecting The Bridge To The Network Cable Support InstallationInstallation Setting The Mode SwitchesNB-25E Connecting The NB20E or NB25E To The Power SourceInstalling the NB20E or NB25E Bridge Installation CHECK-OUT Chapter Testing and LanviewCheck Out Configuration Using LanviewUsing the Forward Broadcast Switch Using the Root Switch

NB25 E, NB20E specifications

Cabletron Systems, renowned for its innovative networking solutions in the late 20th century, introduced the NB20E and NB25E series, which made a significant impact in the realm of network management and reliability. These devices were tailored for businesses seeking to enhance their network infrastructure with efficiency and reliability.

The NB20E is known for its robust performance in medium-sized network environments. It operates with an architecture that allows for seamless integration into existing networks, providing essential features that cater to both versatility and scalability. One of its standout functionalities is the support for multiple protocols, enabling organizations to harness various networking standards without the need for extensive alterations to their current setups.

On the other hand, the NB25E extends these capabilities further, offering enhanced throughput and a more comprehensive range of networking options. This makes it particularly suitable for larger businesses with growing networking demands. The utilization of advanced technologies, such as its embedded intelligence, ensures that the NB25E can efficiently manage and direct network traffic, thus minimizing latency and maintaining optimal performance even during peak usage times.

Both models provide essential characteristics such as a modular design, allowing for easy upgrades and maintenance. This modularity not only prolongs the lifespan of the devices but also provides flexibility for future expansions or modifications as business needs evolve. The systems support various interfaces, catering to diverse environments and ensuring easy connectivity to other networking equipment.

Security is a paramount concern in today’s interconnected world, and Cabletron Systems addressed this in the NB20E and NB25E series. The devices are equipped with advanced security features that protect against unauthorized access and ensure data integrity, providing peace of mind for organizations relying on critical data transmissions.

In addition to their technical advantages, both models offer user-friendly management software, making monitoring and control straightforward even for those with limited networking expertise. This ease of use ensures that companies can leverage their investment fully without requiring extensive training or resources.

In summary, the Cabletron Systems NB20E and NB25E series represent a significant leap in networking technology during their era. With advanced features, modular capabilities, and a commitment to security, these devices remain a noteworthy consideration for businesses looking to enhance their networks and prepare for future growth.
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