Highly Affordable
The BayStack 250 Series 10/100 Autosense Hubs offer excellent affordability to those who are building their networks with future growth in mind.

10/100 Autosensing on Every Port
Every port on a BayStack 250 Series Hub uses autosense technology to automatically detect and support the speed of a connected device. As network performance requirements increase, the BayStack 250 Series Hubs will automatically support any equipment upgrades - without requiring repeated trips to the wiring closet.

Web-Based Network Management
The BayStack 250 10/100 Hub/NMM and BayStack 253 10/100 Hub/NMM include Web-based network management software. This allows network administrators to easily access such key information as device summary, configuration, fault management, statistics, applications, and support. Network managers can access data about their network and individual hubs via the local corporate intranet, or from any World Wide Web-connected PC, anywhere in the world.

Built-In Two-Port Switch
A two-port switch built into the BayStack 250, 253, 254, and 255 Hubs provides high-speed connectivity between 10 Mbps users and 100 Mbps users. No external switch is required to provide data transfers between the 10BASE-T and 100BASE-T segments. It's like having two managed hub stacks with a switch to segment traffic into two smaller collision domains for faster performance.

Easy Stackability
Users can stack up to five BayStack 250 Series Hubs, thus linking up to 120 unmanaged or managed ports in a single hub stack. This ability makes BayStack 250 Series Hubs a simple, scalable and cost-effective solution for supporting growing network environments.

Built-In Network Management Module
A single BayStack 250 or BayStack 253 10/100 Autosense Hub/NMM can manage an entire stack of BayStack 250 Series 10/100 Hubs, providing complete management for up to 120 ports. Users get simple and affordable full-stack manageability for a growing network.

Fully Integrated into Optivity Network Management Software
The BayStack 250 Series 10/100 Autosense Hubs are fully integrated into Optivity network management software, enabling complete SNMP and support for four RMON groups. Network administrators can use Optivity to manage their entire network, including all hubs, switches, and routers, from a single management station. By using Optivity, network administrators can dramatically reduce the total cost of network ownership.

High-Speed Fiber Connectivity
The BayStack 253 and 255 Hubs have a slot for an optional 100BASE-FX media dependent adapter (MDA). The BayStack 250-1FX MDA allows full-duplex fiber connectivity to higher end solutions such as the BayStack 450 Switches and the Accelar* routing switches.

Advanced Analysis and Monitoring with RMON and StackProbe
Advanced Analyzer* management is available with Nortel Networks' StackProbe* RMON probe, which provides full RMON and RMON2 capabilities. Two PassThru* ports on the StackProbe provide in-line monitoring. Application support for StackProbes is incorporated within the Optivity network management system. Network administrators can easily gain advanced network management features without the need for additional wiring.

Fail-Safe Features
The automatic bypass feature automatically bypasses any hub in the stack that fails or loses power. SmartSwap* non-volatile configuration memory automatically saves and restores the configurations of all hubs in the stack through power cycles and hub replacements. This ensures that the network remains operational under demanding conditions. Automatic hub-settings restoration saves time-consuming manual network administration.

Real-Time Hub Status at a Glance
The BayStack 250 Series 10/100 Hubs feature an easy-to-read front-panel LED that shows hub and segment status at a glance, with real-time network monitoring of power, status, collision, and network usage. The displays also enable hub and network operational status to be determined immediately, right in the wiring closet, without the use of network management software. Table 1 shows port and management configurations.

BayStack 250 Series 10/100 Autosense Hub Applications
All BayStack 250 Series 10/100 Autosense Hubs support 10/100 autosensing on all ports. This enables seamless migration from 10 Mbps to 100 Mbps connections, without requiring time-consuming trips to the wiring closet whenever end stations are upgraded to Fast Ethernet.

The BayStack 250 Series 10/100 Hubs offer a high-performance desktop solution for network environments that quickly overwhelm legacy 10 Mbps solutions. The hubs also represent an important part of the Nortel Networks 100BASE-TX evolution strategy, extending the power and adaptability of the BayStack 350 Switches by filling a critical need in evolving networks.

Installed with the BayStack 350 or BayStack 450 10/100/1000 Switches, the BayStack 250 Series 10/100 Autosense Hubs play a key role in the evolution to Fast Ethernet, providing a cost-effective way to improve network response times. Linking a 10/100 hub or stack to a BayStack 350 or BayStack 450 Switch provides the power workgroup with a 100 Mbps connection to centralized resources such as high-utilization servers and routers. The BayStack 250 Series 10/100 Hubs can also be linked to 100BASE-TX router interfaces on Nortel Networks routers to create large-diameter Fast Ethernet networks. The BayStack 253 Hub and the BayStack 255 Hub with the 100BASE-FX MDA provides a full-duplex fiber connection to the network center up to two kilometers.