8-1 - Connecting Devices

Passive Hub

These devices operate below the physical layer. [Five Cats of Connecting Devices]

Active Hub and Repeaters

Operate at the physical layer.

Bridge (Two Layer Switches)

Operates at the Physical and Data Link Layer.

Router (3-Layer Switch)

Operates at the Physical, Data Link, and Network Layers.

Gateway

Operates at all 5 layers. Category of Connecting Device.

Passive Hub

The simplest type of network connecting device. It acts as a physical connection point and uses the star topology. It has no electronic components for signal processing. Does not require electrical power.

Active Hub

Essentially a multiport repeater. Uses a physical star topology. It regenerates and retransmits the signal to all connected devices. Requires an external power source. Does not filter or direct traffic.

Repeaters

A network device that operates at the physical layer of the internet model. It extends the distance a signal can travel within a network.

Amplifier

A device that can strengthen both signal and noise.

Bridge

Operates in both the physical and data link layer. It has a filtering capability and it does not change the physical MAC addresses in the frame.

Frame Format

Each LAN type has its own ___ ____.

Maximum Data Size

If the data size is too large, it must be fragmented into several frames.

Data Rate

Since each LAN has different ___ rate, it must buffer the frame to compensate for the difference.

Bit Order

It can either be sending the MSB or LSB first. Each LAN is different.

Security

LANs that implement _____ measures. Involves encryption and decryption.

Multimedia Support

LAN that support _____. Quality of services needed for this type of communication (?)

Transparent Bridge

A bridge that is invisible to other devices on the network. It doesn’t reconfigure the network, it blocks or forwards data according the MAC Address.

Source Routing Bridge

A bridge that was developed and designed by IBM for token ring networks. The frame’s route in in a data frame by the source station, allowing routing operations.

Translational Bridge

A bridge that converts the received data from one network system to another. Used to communicate between two different types of networking system.

Frame Forwarding

A criterion of a transparent bridge. It states that the bridge must forward frames to their intended destination.

Address Learning

Modern Transparent Bridges use a learning process to build their forwarding table. Old bridges uses static types. While we now use dynamic learning.

Dynamic Learning

A type of learning where they observe the source MAC of incoming frames and update their table to remember which device is connected to which port.

Loop Resolution

A criterion of transparent bridges. It is said that transparent bridges work well when there are no ____ in the network. Usage of Spanning trees to prevent them.

Source Routing Bridges (SRB) Algorithm

Developed by IBM and was proposed to the IEEE 802.5 Committee as the means to bridge between all LANs.

Routers

A layer 3 device in the OSI model that forwards packets based on logical addresses. It connects networks, does routing decisions, and dynamically updates the routing tables.