Multicast Packets, Total Errors | Cabletron Systems SEHI-22/24

Using the SEHI Hub View

Multicast Packets

The number of multicast packets received by this device, module, or port since the window was last opened or reset. Multicast packets are simultaneously addressed to more than one address, but fewer than all addresses.

Collisions

The number of collisions recorded by this device, module, or port since the window was last opened or reset. The SEHI counts both receive collisions — those detected while a port is receiving data — and transmit collisions — those detected while a port is transmitting data (i.e., the port has transmitted one of the colliding packets); however, these counts are combined and a single total value is displayed. Collisions of this type (called “legal” collisions, as opposed to the OOW collisions described below) are a natural by-product of a busy network; if you are experiencing high numbers of collisions, it may be time to redirect network trafﬁc by using bridges or routers. Extremely high collision rates can also indicate a data loop (redundant connections) or a hardware problem (some station transmitting without listening ﬁrst).

Total Errors

The number of errors of all types recorded by this device, module, or port since the window was last opened or reset.

Alignment Errors

The number of misaligned packets recorded since the window was last opened or reset. Misaligned packets are those which contain any unit of bits which is less than a byte — in other words, any group of bits fewer than 8. Misaligned packets can result from a packet formation problem, or from some cabling problem that is corrupting or losing data; they can also result from packets passing through more than two cascaded multi-port transceivers (a network design which does not meet accepted Ethernet spec).

CRC Errors

CRC, or Cyclic Redundancy Check, errors occur when packets are somehow damaged in transit. When each packet is transmitted, the transmitting device computes a frame check sequence (FCS) value based on the contents of the packet, and appends that value to the packet. The receiving station performs the same computation; if the FCS values differ, the packet is assumed to have been corrupted and is counted as a CRC error. CRC errors can result from a hardware problem causing an inaccurate computation of the FCS value, or from some other transmission problem that has garbled the original data. The CRC error counter shows the total number of CRC errors recorded since the window was last opened or reset.

OOW Collisions

The number of out-of-window collisions recorded since the window was last opened or reset. OOW collisions occur when a station receives a collision signal while still transmitting, but more than 51.2 ∝sec (the maximum Ethernet propagation delay) after the transmission began. There are two conditions which can cause this type of error: either the network’s physical length exceeds IEEE

Monitoring Hub Performance

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SEHI-22/24, SEHI-32/34 specifications

Cabletron Systems was a notable player in the networking hardware market during the rise of local area networks (LANs) in the late 20th century. Among its innovative products were the SEHI-22/24 and SEHI-32/34 modules, which were designed to enhance network capabilities in enterprise environments.

The SEHI-22/24 and SEHI-32/34 were versatile high-performance Ethernet switch modules that offered significant advantages in network management and connectivity. These modules were designed to work with Cabletron's modular switching and routing architecture, allowing for scalable solutions tailored to specific network demands. A key feature of the SEHI series was its support for a range of Ethernet standards, ensuring compatibility with diverse networking environments.

One notable characteristic of the SEHI-22/24 was its ability to support both 10Base-T and 100Base-TX Ethernet technologies. This dual support enabled organizations to leverage existing 10 Mbps infrastructure while facilitating upgrades to 100 Mbps speeds without needing a complete overhaul of the network. Similarly, the SEHI-32/34 offered even greater connectivity options, accommodating more users and devices while maintaining high throughput and low latency.

In terms of management features, the SEHI series was equipped with extensive traffic management capabilities, including Quality of Service (QoS) features that prioritized bandwidth for critical applications. This ensured that essential services such as voice over IP (VoIP) and video conferencing could function optimally, even during heavy network loads.

Furthermore, both modules featured advanced diagnostics and monitoring tools that provided network administrators with critical insights into traffic patterns and potential bottlenecks. This functionality was essential for maintaining network health and optimizing performance, especially in dynamic business environments.

Security also played a crucial role in the design of the SEHI-22/24 and SEHI-32/34. The modules incorporated support for various authentication methods and access controls, ensuring that sensitive data remained protected within the corporate network.

In summary, Cabletron Systems’ SEHI-22/24 and SEHI-32/34 offered significant advancements in Ethernet switching technology, allowing organizations to build robust, scalable, and secure networks. With their impressive features, compatibility, and capacity for management and security, these modules were instrumental in shaping reliable networking solutions for enterprises navigating the rapidly evolving digital landscape.

Cabletron Systems SEHI-22/24 manual Multicast Packets, Total Errors, Alignment Errors, CRC Errors

Models: SEHI-22/24 SEHI-32/34