Alteon OS Application Guide

Overview

Spanning Tree Group (STG) detects and eliminates logical loops in a bridged or switched net- work. When multiple paths exist, Spanning Tree configures the network so that a switch uses only the most efficient path. If that path fails, Spanning Tree automatically sets up another active path on the network to sustain network operations.

GbESM supports IEEE 802.1d Spanning Tree Protocol. It is compatible with PVST+ by con- figuring each STP Group in different STP instances.

NOTE – The GbESM also supports IEEE 802.1w Rapid Spanning Tree Protocol, and IEEE 802.1s Multiple Spanning Tree Protocol. For more information, see Chapter 6, “Rapid Spanning Tree Protocol/Multiple Spanning Tree Protocol.”

The relationship between port, trunk groups, VLANs, and Spanning Trees is shown in Table 5-1.

Table 5-1Ports, Trunk Groups, and VLANs

Switch Element

Belongs to

 

 

Port

Trunk group

 

or

 

One or more VLANs

 

 

Trunk group

One or more VLANs

 

 

VLAN (non-default)

One Spanning Tree group

 

 

NOTE – Due to Spanning Tree’s sequence of listening, learning, and forwarding or blocking, lengthy delays may occur.

You can use Port Fast Forwarding (/cfg/port x/fastfwd/ena) to permit a port that participates in Spanning Tree to bypass the Listening and Learning states and enter directly into the Forwarding state. While in the Forwarding state, the port listens to the BPDUs to learn if there is a loop and, if dictated by normal STG behavior (following priorities, and so on), the port transitions into the Blocking state. This feature permits the GbE Switch Module to inter- operate well within Rapid Spanning Tree networks.

106 „ Chapter 5: Spanning Tree Group

42C4911, January 2007

Page 105 Page 107
Page 106
Image 106
Nortel Networks 42C4911 manual 1Ports, Trunk Groups, and VLANs
Page 105 Page 107

42C4911 specifications

Nortel Networks 42C4911 is a key hardware component designed to meet the needs of modern telecommunications infrastructure. As part of Nortel's extensive portfolio, the 42C4911 has made a significant impact on network design and operation, particularly in enterprises requiring reliable and efficient communication solutions.

One of the standout features of the 42C4911 is its modularity. This allows for flexible configurations and upgrades, enabling organizations to adapt to changing technology requirements and business demands. The design philosophy behind the 42C4911 emphasizes scalability, allowing users to start with a basic setup and expand it as their networking needs grow. This feature is particularly appealing to medium and large enterprises that anticipate increased data and communication requirements over time.

In terms of technology, the 42C4911 supports various telecommunications standards, making it versatile for multiple applications. It typically integrates with other Nortel equipment and can work with third-party devices, ensuring seamless interoperability across different platforms. This is critical as organizations look to create unified communications systems that can handle voice, data, and video traffic efficiently.

The 42C4911 is known for its robust performance and reliability. It is designed to operate continuously under demanding conditions, which is essential for organizations that rely on constant connectivity for their operations. Its built-in redundancy features help safeguard against potential failures, thus enhancing the overall stability of the network. This reliability is further complemented by Nortel's commitment to high-quality manufacturing standards, ensuring that users receive a durable and efficient product.

Security is another major consideration for any networking device, and the 42C4911 provides advanced security features to protect sensitive data. With increasing cybersecurity threats, organizations prioritize devices that offer strong encryption and access control mechanisms. The 42C4911 addresses these needs while facilitating secure communication channels for users, which is essential in today's increasingly interconnected world.

Overall, the Nortel Networks 42C4911 stands out as a versatile and powerful component in the telecommunications landscape. Its modular design, compatibility with diverse technologies, reliability, and emphasis on security make it an appealing choice for organizations looking to enhance their networks. As companies continue to navigate the complexities of communication, devices like the 42C4911 play a crucial role in ensuring that they remain connected and efficient.
Top Page Image Contents