-: Network availability, in this section of the course, 2 2
we're going to talk about network availability. 3 3
Now, network availability is a measure 4 4
of how well a computer network can respond to connectivity 5 5
and performance demands that are being placed upon it. 6 6
This is usually going to be quantitatively measured 7 7
as uptime, where we count the amount of time 8 8
the network was up, 9 9
and divide that by the total amount of time 10 10
covered by the monitoring period. 11 11
For example, if I monitor the network for a full year 12 12
and I only had five minutes and 16 seconds of downtime 13 13
during that year, this would equate to an uptime of 99.999%. 14 14
Now this is known as the five nines of availability. 15 15
And it's considered the gold standard 16 16
in network availability. 17 17
This is considered to be an extremely available 18 18
and high quality network, 19 19
but there is going to be downtime in your networks. 20 20
It's a fact of life, devices fail, connections go down, 21 21
and incorrect configurations are sometimes going to be applied. 22 22
There are a lot of reasons that downtime occurs, 23 23
but our goal is to minimize that downtime 24 24
and increase our availability. 25 25
In order to reach the highest levels of availability, 26 26
we need to build in availability and redundancy 27 27
into our networks from the beginning. 28 28
We also are going to use quality of service 29 29
to ensure that our end-users are happy with the networks 30 30
and the services that we're providing them. 31 31
So in this section on network availability, 32 32
we're really going to focus on two domains. 33 33
We're going to see domain two, 34 34
which is network implementations, 35 35
and domain three, network operations. 36 36
In here, we're going to talk about two objectives. 37 37
Objective 2.2 and objective 3.3. 38 38
Now objective 2.2 states, that you must compare and contrast 39 39
routing technologies and bandwidth management concepts. 40 40
Objective 3.3 states, 41 41
that you must explain high availability 42 42
and disaster recovery concepts 43 43
and summarize which is the best solution. 44 44
So let's get started talking 45 45
all about the different ways for us 46 46
to increase the availability, reliability, 47 47
and quality of service within our networks 48 48
in this section of the course. 49 49
(ethereal music)