8.8 Speed Detection

Speed detection on the 8260 token-ring media modules is achieved in one of two ways depending on the module type.

8.8.1 Speed Detection on Active Modules

For the active modules, speed detection is accomplished by counting the number of transitions in the incoming data over a set period of time. If the rate of transition is less than 4.5 MHz the station would only be allowed to enter 4 Mbps token-rings and if the rate of transition is more than 4.5 MHz, the station would only be allowed to enter 16 Mbps token-rings. So, if the module detects that the station is trying to insert at the wrong speed, the speed mismatch will be detected and the station will be prevented from inserting into the ring and disrupting its operation.

When an incorrect speed is detected, the port is not allowed to unwrap (note that under normal circumstances, when the station enters the ring, the port is in wrapped state) and the status of the port is set to ″speed mismatch″. The port will then be checked again when a transition of phantom is detected or when the user disables and then enables the port.

Note

During the configuration of the 8260, you will set the ring speed for the networks (token-ring-1 thru token-ring-10 and isolated_1 thru isolated_11) using the following DMM command:

SET NETWORK TOKEN_RING token_ring_n RING_SPEED {4mbps16mbps}

SET NETWORK TOKEN_RING isolated_n {slot} RING_SPEED {4mbps16mbps}

Once, you set the ring speed, any port attached to that ring will assume the speed of the ring. You do not set the ring-speed for each port.

8.8.2 Speed Detection on Passive Modules

Passive modules implement a software-based method to detect incorrect ring speed on the attaching stations.

When a station inserts into the ring on a passive module, the module will first wrap all the other ports on the module and also the module off the backplane. Then, the Recovery ASIC in the module sends an All-Station MAC frame (at the speed of the ring to which this port is assigned) on the newly inserted port. The ASIC will wait for this MAC frame to be returned and it will inspect the ″ A″ (address-recognized) and ″C″ (frame-copied) bits on the received frame.

∙If the ″ A″ and ″C″ bits are set to B′1′ the station which just inserted into the ring is operating at the correct speed. The Recovery ASIC will then allow the station to insert into the ring and will also unwrap all the other ports on the module allowing the existing users to resume access to the ring. During this process, the existing stations on the module are unable to access the ring. However, since this is a very short time, no user sessions are expected to be terminated as a result of this temporary inability to access the ring.

Chapter 8. 8260 Token-Ring Support 149

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IBM 8260 manual Speed Detection on Active Modules, Speed Detection on Passive Modules
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8260 specifications

The IBM 8260 is a significant entry in the realm of enterprise servers, recognized for its performance, scalability, and robust features designed to cater to demanding business environments. It primarily serves as a high-capacity server for large organizations, capable of handling extensive workloads and complex applications without compromising speed or efficiency.

One of the standout features of the IBM 8260 is its powerful processing capabilities. It typically comes equipped with multiple processor units based on the IBM POWER architecture, which is renowned for its high-performance computing. This architecture allows the server to execute numerous simultaneous tasks, making it ideal for environments that require multitasking and high throughput.

Memory capacity is another key characteristic of the IBM 8260. Depending on the specific configuration, it can support substantial amounts of RAM, ensuring that applications can run effectively without the bottlenecks often associated with data-intensive tasks. This is crucial for enterprises that rely on real-time data analytics, large database management, and resource-heavy applications.

In terms of storage, the IBM 8260 offers flexible options. It supports a variety of storage solutions, including solid-state drives (SSDs) and traditional hard drives, catering to different performance and capacity needs. This scalability in storage helps organizations manage their data effectively while ensuring quick access and retrieval times.

Connectivity is also a prominent feature of the IBM 8260. The server includes advanced networking capabilities, supporting various protocols and technologies that facilitate fast data transfer and communication between devices. This enhances overall network performance, essential for businesses that depend on cloud computing and distributed computing environments.

Additionally, the IBM 8260 is designed with a focus on reliability and availability. It incorporates redundant components, such as power supplies and cooling systems, minimizing the risk of downtime. This is critically important for enterprises that require continuous availability of services.

The server’s management features are also noteworthy. IBM provides a suite of management tools that allow IT administrators to monitor performance, configure hardware settings, and troubleshoot issues seamlessly. This ease of management is bolstered by automation capabilities, enabling organizations to enhance operational efficiency.

In conclusion, the IBM 8260 stands out in the competitive server landscape due to its high processing power, extensive memory and storage options, advanced connectivity, reliability features, and robust management tools. Such attributes make it a viable choice for organizations seeking to enhance their IT infrastructure and streamline their operations effectively.
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