Operation

DC/DC Converter

The DC/DC converter converts the 48 VDC on the system power bus to the necessary operating voltages for its host network services module. The diagnostic controller monitors and controls the operation of the DC/DC converter.

INB Interface

The INB Backplane is designed to transport fixed length data blocks between modules in the SmartSwitch 9000 using an INB Time Division Multiplexing (ITDM) design. The SmartSwitch 9000 INB bus delivers 2.0 Gbps of true data bandwidth with all control and management communication being serviced on the 8 bit out-of-band bus. The time slices of the INB manager operates in all three modes at once, without user intervention.

Arbitration for the backplane is accomplished in the INB Time Division Multiplexing (ITDM) logic. The arbitration is a three-level scheme that ensures that no one can get the backplane for more than one time slice at a time.

The ITDM RAM contains 256 4-bit locations. This RAM is used to hold slot numbers of modules participating in INB backplane arbitration. The arbitration engine accesses this RAM once every time slice to get a slot number. That slot number will be granted access on the next time slice if it is requesting. The arbitration engine is always one time slice ahead, meaning that the value read from the RAM is for the next time slice, not the current time slice.

The RAM is programmed on system power-up or when ever a module is inserted/removed from the SmartSwitch 9000 chassis. There is a module discovery program running that will detect these events. The amount of RAM to be used and the position of the slot numbers in the RAM is determined by a higher level system management program.

ITDM Arbitration levels

The three levels of arbitration guarantee that a module will get its allocated bandwidth plus some more depending on what levels of arbitration it is participating in.

ITDM RAM Allocation (Level 1)

This level guarantees access to the backplane. When a module requests access to the backplane, it will get access to it when it's slot number is placed onto the bus. This will ensure predicted or predetermined access to the backplane.

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Cabletron Systems 12 manual DC/DC Converter, INB Interface, Itdm Arbitration levels
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12 specifications

Cabletron Systems 12, widely regarded for its impact on networking technology in the late '80s and early '90s, has become a pivotal part of the history of data communications. This product marked a significant leap forward in the area of local area networking (LAN), blending reliability with advanced capabilities tailored for varied business needs.

One of the standout features of Cabletron Systems 12 is its ability to facilitate scalable networking solutions. It was designed with modularity in mind, allowing businesses to expand their network infrastructure as their needs evolved. This characteristic made it particularly appealing to organizations experiencing rapid growth, as it provided a cost-effective way to upgrade and add components without a complete system overhaul.

The architecture of Cabletron Systems 12 was based on a multi-layer switching technology. This approach enhanced the speed and efficiency of data transmission across the network. By employing a combination of hardware and software solutions, it minimized bottlenecks and ensured superior performance during high-traffic periods. Enhanced throughput made it suitable for a range of applications, from small businesses to enterprise-level networks.

Another significant feature was its support for a diverse set of network protocols, including Ethernet and Token Ring. This flexibility allowed organizations to integrate various networking technologies into a single cohesive system, thereby protecting their investment in existing infrastructure while still enabling new technology adoption.

The design of Cabletron Systems 12 also prioritized management and monitoring capabilities. With user-friendly interfaces and tools, network administrators could easily configure and manage their networks, enhancing overall operational efficiency. Real-time diagnostics and reporting features helped in troubleshooting and maintaining optimum network performance.

In addition to its performance-oriented features, Cabletron Systems 12 was also noted for its robust security protocols, which were crucial in an era where cyber threats were beginning to rise. Comprehensive security measures ensured that data integrity and privacy were maintained, providing peace of mind for organizations relying on digital communications.

Overall, Cabletron Systems 12 encapsulated the technological innovations of its time, offering a blend of speed, scalability, and security. Its ability to adapt to the changing landscape of networking set a precedent for future developments in the field, making it a noteworthy milestone in the evolution of communication technology.
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