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From YouTube: Why and how to use CDNs
Description
Season 1, episode 2 provides details on what Content Delivery Networks (CDN) are and why they should be used.
A
Good
day
and
welcome
to
season
1
episode,
2
of
the
ODSP
performance
miniseries.
Today's
episode
is
on
sealians
the.
Why
and
what
my
name
is
Scott
genomics
senior
program
manager
in
the
one
Robin
shape
on
engineering
team
and
what
you'll
see
as
part
of
these
webcasts
that
we're
doing
is
they'll
be
little
10
minute
segments,
and
this
is
the
second
one
in
the
unit
first
part
of
the
series.
A
Please
continue
to
watch
other
ones
if
you
wanted
to
go
into
deeper
as
you'll
see
as
we
progressed
into
each
one.
They'll
go
deeper
and
deep
into
different
elements
that
we
want
to
help
you
with
or
advise
on
what
to
do
in
your
work,
your
shape
on
online
space
right.
So
today's
agenda,
why
will
you
see
the
internship
on
a
line
other
work
identifying
which
shape
on
CD
is
used,
and
then
the
CDN
command
set
the
deeper
into
the
implementation
and
how
to
do
that?
It
will
be
in
the
next
episode.
A
So,
first
of
all,
why
you
see
the
ends?
If
you
look
on
the
picture
on
the
graph,
what
you'll
see
is
that
on
the
map
should
I
say
you'll,
see
that
we
have
a
United
Kingdom
location
with
a
United
Kingdom
user.
You
have
the
United
States
user.
You
can
look
on
the
opposite
side
and
you
have
that
your
SharePoint
farm
is
located
with
the
United
States
within
North
America
from
their
location
looks
around
about
probably
the
Chicago
data
center.
In
this
particular
scenario.
A
Now,
if
you
have
a
look,
we've
got
these
long
green
lines
and
those
green
lines
illustrate
the
traffic
or
the
long
haulers
would
like
to
put
it
that
a
user
would
make
when
they
make
requests
to
ship
on
online.
Now,
while
what
is
important
there
is.
The
first
part
is
that
we
reuse
pre-existing
connections.
You
don't
have
this
additional
handshakes
and
additional
slow
sort
of
traffic.
That
would
happen
otherwise,
whatever
this
I
mean
using
the
UK
and
I'm
now
gonna
request
an
image
or
a
JavaScript
file
from
or
a
job
or
CSS
file
from
SharePoint.
A
If
I
pull
it
from
a
normal
library,
what'll
happen
is
you'll,
see
it'll
access
the
database
database.
Well
then,
streaming
across
and
bring
it
back
to
the
user
and
go
all
the
way
along
and
all
the
way
back
across
the
line.
That's
alliteration
you
get
to
the
use
of
the
UK
and
you'll
see
the
same
effect
will
happen
for
the
u.s.
user.
You
can
imagine
the
experiences
yes,
so
what
it's
a
Meg
file?
What's
the
big
deal,
all
that
meg
is
gonna
traverse
the
line
for
each
and
every
single
user
in
that
space.
A
Now
what
happens
if
we
implement
CD
ends
those
changes
now
and
instead
of
the
file
not
coming
all
the
way
back
because
of
the
CDN
is
multiple
locations
around
the
world
and
in
fact
we
have
them
in
most
cities
around
the
world,
you
will
see
that
the
CDN
would
automate
the
top
right.
You
can
see
it
there
that
it
would
feed
directly
from
this
Union
to
the
user.
What
that
means
is
there's
less
traffic
flow
along
that
line,
it's
less
than
lay
getting
back
to
the
user,
and
we
see
quite
a
significant
improvement
in
speed.
A
The
same
effect
would
happen
for
the
u.s.
user,
even
though
the
distances
might
be
slightly
shorter.
It
is
a
case
of
being
able
to
serve
the
CDN
close
to
the
location
from
the
user.
We
all
know
that
traffic
close
to
you
is
a
lot
faster,
so
jumping
straight
in
now
that
you've
seen
how
what
TD
ins
do
for
us,
let's
jump
straight
into
what
public
Citians
are
and
how
they
work.
A
Now
we
haven't
quite
defined
all
the
types
we'll
get
into
the
types
shortly,
but
I
wanted
to
cover
the
brief
on
how
they
work
and
then
we'll
go
into
the
different
options
and
which
one
you
use.
That's
the
ultimate
question
right.
So,
if
you
look
at
this
diagram
and
it
is
available
online
as
well,
it's
it
looks
a
little
bit
more
complicated
than
it
is.
First
of
all,
the
user
makes
a
cause.
You
can
see
it's
step
one
and
make
a
call
to
ship
on
a
line.
A
That
call
then
goes
and
says:
hey
going
to
be
the
CSS,
the
PNG,
the
JavaScript,
the
JPEG,
whichever
files
it
is,
go
and
get
those
files
for
me
now.
Those
are
things
could
be
a
logo
on
the
page.
It
could
be
the
stylesheet
at
using,
as
you
can
see,
the
CSS
and
then
the
jas,
which
is
a
JavaScript
file,
and
it
could
be
either
of
those.
It
will
then
go
and
request
it
from
the
content
delivery
network,
the
content,
delivery
network.
A
If
it's
the
first
time
it
is
it's
being
asked
for
that
file
will
request
that
file
from
ship
on
ship
on
moment,
synchronize
it
and
within
15
minutes.
It
will
have
the
file
and
will
upload
that
file
into
the
CDN.
Now
in
a
public
CDN
that
location
doesn't
change
and
that
will
then
replicator
on
the
world,
so
our
CDN
locations
around
the
world
will
they
be
replicated
too
so,
no
matter
where
users
lives,
they
will
then
get
it
from
the
closest
location
to
them.
A
I
might
ask
what
happens
if
it's
not
in
the
city
and
yet
well.
They
will
serve
it
from
the
ship
on
library'
and
once
it
has
synchronizing
to
the
CDN
equal
then
served
from
the
CDN.
From
that
point
onwards,
the
only
restriction
on
this
is
that
it
must.
You
must
be
coming
from
a
ship
on
referral.
Now
there
was
a
ship
on
page
and
bear
in
mind.
This
is
public
CDN.
It
doesn't
mean
that
everyone
can
access
it.
Yes,
if
they
had
the
URL
directly,
they
could
provide
it.
They
were
coming
from
SharePoint.
A
So,
yes,
it
is
public.
Keep
that
in
mind
that
if
it's
personal
IP
you
don't
want
to
put
on
there
totally
understand
that
this
is
design
facade
assets
and
you'll.
See
that
as
we
go
on
right,
what
does
it
look
at
private
CDN?
A
private
tini
is
a
little
different
as
all
see
in
point
number
one
over
there
does
make
the
request
to
shape
on.
It
then
goes
and
says:
yes
give
me
the
CSS,
the
PNG,
the
javascript
file
JPEG,
whichever
one
you
want
to
do,
and
then
it
actually
goes
to
the
content
delivery
network.
A
A
So
if
you
try
and
HOD
kodos
every
60
minutes,
the
URL
becomes
invalid,
don't
think
that
you
can
do
it
an
old
or
keep
it
after
60
minutes.
The
URL
is
no
longer
available
and
you
cannot
access
from
that
location,
and
this
is
why
this
is
the
private
CDN.
This
is
typically
for
assets
that
you
want
more
higher
level
of
security
on.
You
want
permissions,
for
example,
that
hey
we
don't
all
us
or
everything
going
or
being
available,
and
if
someone
gets
the
URL,
we
don't
have
to
access
it.
A
Well,
if
they
happen
to
get
the
URL
and
their
permissions,
they
will
be
able
to
get
there
without
having
gone
from
the
location.
You
specify,
you
might
say:
well,
that's
not
private.
In
is
it
well
that
is
think
about
it.
If
I
really
wanted,
if
I
was
someone
within
your
company
and
I
really
wanted
to
share
that
picture,
or
that
image
or
whatever
that
might
be,
I
could
simply
take
a
picture
of
my
phone
and
share
it
in
CD
ends.
A
You
would
have
to
physically
go
and
copy
this
full
long
URL
with
the
encryption
or
the
cookie
details
in
it
completely
in
order
to
try
near
to
the
c2
to
the
actual
file.
So
it
is
a
secure
option.
That's
offered
now
CD
ends,
and
perhaps
something
to
mention
is
those
files
physically
live
in
the
different
locations
where
we
replicate
you.
So
if
you've
got
data
the
residency
concerns
today,
those
files
that
you
put
in
there
should
not
be
things
that
are
obviously
restricted
by
data
residency,
because
I
have
a
user
sitting
with
the
United
Kingdom.
A
But
my
day
the
residency
is
North
America
when
they
access
that
the
first
time
they
access
it,
it
will
be
synchronized
in
the
CDN
within
the
United
Kingdom.
So
you
need
to
obviously
take
that
into
consideration
and
verify
that
with
your
privacy
Department
right
so
which
CDN
should
we
use?
First
of
all,
we
there
are
more
than
public
and
private
public
and
private
on
the
Microsoft,
SharePoint
ones
offered
an
office.
A
365
you'll
see
there's
a
third
one
which
I
refer
to
as
public
common,
and
then
this
particular
example
as
you'll
see
in
the
bottom
right
is
an
AJAX
javascript
file.
Why
access
the
javascript
file
from
your
own,
your
own
library?
Why
couldn't
your
own
CD
and
there's
no
purpose
behind
that
use
the
public
common
CDN?
As
you
can
see
the
example,
there
is
Ajax
dot,
asp
net
cbn.com
falls
Ajax
and
then
the
version
of
the
file
that
you
needed
to
use
you'll
see
later
on
as
we
get
into
it.
A
You'll
see
that
it
actually
shows
an
example
of
why
right
couple
of
quick
points,
it's
a
tenant
level,
you
control
it
with
folders,
otherwise
known
as
origins
when
you
turn
it
on
by
default.
We
have
a
couple
of
automatic
ones,
as
you
can
see,
auto
origins
and
then,
of
course,
the
HTTP
protocol.
This
is
a
very
important
one.
It
allows
it
has
more
threads
and
six
HTTP
1.1
user.
Six
threads
and
you'll
see
that
it
actually
slows
down
the
page
with
assets
waiting
in
line
to
queue
up
the
responses.
You
have
automatic
you
rewrite.
A
A
Public
is
site
assets,
particular
things
like
logos,
CSS
files,
JavaScript
files,
private
and
physical
content.
In
other
words,
I
got
mine.
We
launched
my
new
uniform
and
it's
very
problem
within
the
company,
and
we
want
pictures
of
it
and
therefore
that
should
go
into
a
private
and
I've
already
been
through
the
points
on
that
right.
So
if
we
look
at
the
URLs
really
quickly,
you'll
see
that
the
public
CD
in
one
run
in
the
beginning,
you'll
see
in
the
top.
It
says
public
CD
and
not
sharing
online,
a
common
intersection.
A
That's
in
a
name
for
private
you'll
notice
of
sorts
of
private
CD
and
open
online.com
and
again
the
tenant
name,
but
you'll
also
notice
to
the
end
of
it
that
is
God
and
eats
and
oats
on
here,
and
that's
really
just
how
it
bulbs
up
and
encrypts,
and
this
changes
every
60
minutes
as
I
mentioned
you'll,
also
see
that
we
have
additional
ones.
For
example,
internal
HBO
CD
ends
those
are
internal,
meaning
those
aesthetic
ones
that
we
as
Microsoft
use
for
some
of
the
assets.
A
We
obviously
want
to
put
in
sealians
as
well,
and
then
the
public
comment
CD
an
example:
I
showed
you
I
spoke
to
you
about
for
the
jQuery
you'll
notice.
It
takes
one
and
a
half
seconds
to
load
from
your
SharePoint
library,
but
if
we
pull
it
from
the
default
or
from
the
location
from
jQuery,
it
takes
469
milliseconds.
In
this
example,
that's
a
saving
of
over
a
second
imagine
five
of
those
files-
that's
five
seconds
that
even
will
cost
your
page
by
simply
not
optimizing.
A
What's
there
and
then
share
puts
he
ends
and
the
shape
one
framework
not
going
to
touch
too
much
on
this.
But
basically,
when
you
use
the
ship
on
framework-
and
you
have
CN
is
enabled
by
default,
we
have
the
client-side
assets,
library
or
folder,
put
into
the
CDN
and
you'll
see
that
the
JavaScript
files
that
you
upload
will
automatically
go
there
for
you
and
then
just
closing
on
I'm
not
going
to
touch
too
much
on
this
as
well
as
we
cover
it
later.
This
is
just
the
CDN
come
on
sit
and
in
the
coming
videos.