Specifications

Niagara Release 2.3
Revised: May 22, 2002 Niagara Networking & Connectivity Guide
Chapter 1 Understanding Networking and IP Addressing
Introduction to Networking
1–6
Ring topologies consist of several nodes joined together to form a circle. Messages
move from one node to the next in one direction only: When a node receives a
message that is addressed to itself, the message is copied and placed back on the
network with a modification indicating that it was received.
Figure 1-3 Ring topology.
Hubs When LANs were first developed, all computers were connected to a single cable that
was strung from location to location. Not only was it difficult to add new computers
to the LAN, but if there was a break in the cable, the whole LAN was disrupted. A
hub is a hardware component that connects many cables in one device. They are used
to break up the LAN into smaller point-to-point segments that support multiple
networked resources. When using hubs, if any one segment has trouble, only
computers on that segment are affected. Hubs also allow the network structure to
change without restringing cable—simply add, move, or delete devices at the hub.
Hubs are mandatory in 10BASE-T twisted pair Ethernet as well as Token Ring
networks.
• Active hubs have the ability to amplify a signal and retransmit it.
• Passive hubs simply pass a signal through without conditioning it.
• Intelligent hubs have switching and management capabilities that allow them
to make choices as to which network path is used to transmit signals.
• Switching hubs (switches) can increase the number of PCs connected to a LAN
by breaking it down into more manageable virtual segments. Whereas a hub
requires all resources to share the bandwidth of the network, switching hubs
give any two nodes on the network the full bandwidth of the line.
The ring topology connects each PC to
two others. Each network adapter has
to take date from one machine and
pass it on to the next.