Exam Essentials Flashcards
Differentiate between a switch and a route
Switches operate at level two of the OSI model and only read frame hardware addresses in a frame to make switching decisions.
Routers read at layer three and use rooted (logical) addresses to make forwarding decisions on a packet.
Understand the term SOHO
SOHO, stands for small office/home office, a small network connecting a user or small handful of users to the Internet and office resources such as servers and printers. ASOHO usually comprises just one router and a switch or two, plus a firewall.
Define three tier architecture
The Cisco hierarchical model can help you design, implement and manage a scalable, reliable and cost-effective hierarchical internetwork.
Cisco defines three layers of hierarchy, the core, distribution and access, each with specific functions.
It’s referred to as a 3 tier network architecture.
Define two tier architecture
Two tier architecture is also referred to as the collapsed core design because it’s only two layers. But in concept it’s like the three tier only less expensive and geared for smaller companies.
The design is meant to maximise performance and user availability to the network, while still allowing for designability overtime.
In a two tier, The distribution layer is merged with the core layer.
Define spine-leaf
Also referred to as leaf-and-spine topology.
There are switches found at the ‘top of rack’ (ToR) that connect to the ‘leafs’ (devices/nodes) in the rack.
Each switch connects to the every spine switch for redundancy.
Remember WAN terms and definitions for:
CPE
DTE
CSU/DSU
Demarcation point
Local loop
Central office
To network
Fibre optic converters
CPE - Customer Premises Equipment.
Typically owned by the subscriber and located on subscribers premises
DTE - data termination equipment.
A device is considered DTE if it’s either a source or destination for digital data.
CSU/DSU - channel service unit/data service unit.
This is a device that used to connect DTE to a digital circuit like a T1/T3 line. CSU/DSU provides clocking of the line for devices to use.
Demarcation point - This is the precise spot where the service providers responsibility ends and the CPE begins.
Local loop - The local loop connects the demarcation point to the closest switching office referred to as the central office
Central office - this point connects the customers network to these providers switching network. Central office (CO) sometimes also referred to as point of presence (POP).
Toll network - the tone network is a trunk line inside a WAN providers network. This network is a collection of switches and facilities owned by the Internet service provider (ISP).
Optical Fibre converters - optical fibre converters are used where a fibre-optic Link terminates to convert optical signals into electrical signals and vice versa. These can be implemented as part of a router or switch device.
