...
This
...
page
...
provides
...
different
...
sort
...
of
...
data
...
analysis
...
using
...
ping
...
and
...
traceroute
...
data.
...
Delays:
...
There
...
are
...
three
...
types
...
of
...
delays
...
a
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packet
...
can
...
have
...
during
...
its
...
transmission
...
from
...
source
...
to
...
destination.
...
- Propagation
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- delay(PD):
...
- A
...
- time
...
- required
...
- to
...
- send
...
- a
...
- single
...
- bit
...
- from
...
- one
...
- hop
...
- to
...
- another
...
- along
...
- the
...
- path.
...
- Transmission
...
- delay(TD):
...
- A
...
- time
...
- required
...
- to
...
- transmit
...
- whole
...
- packet
...
- from
...
- a
...
- hop
...
- along
...
- the
...
- outgoing
...
- link.
...
- Queing
...
- delay(QD):
...
- A
...
- time
...
- required
...
- by
...
- the
...
- packet
...
- to
...
- wait
...
- in
...
- the
...
- buffer
...
- before
...
- being
...
- ready
...
- for
...
- transmission
...
- into
...
- an
...
- outgoing
...
- link.
...
Total
...
delay
...
is
...
the
...
sum
...
of
...
all
...
PD,TD
...
and
...
QD
...
along
...
the
...
path.
...
Round
...
trip
...
time(RTT)
...
is
...
equal
...
to
...
2
...
*
...
total
...
delay,
...
considering
...
reverse
...
path
...
takes
...
the
...
same
...
route
...
and
...
delays.
...
Note:
...
PD
...
is
...
normally
...
taken
...
as
...
0,
...
compared
...
to
...
other
...
delays.
...
Lets
...
say,
...
we
...
have
...
to
...
find
...
minimum
...
buffer
...
sizes
...
along
...
the
...
path.
...
Practically,
...
it
...
is
...
very
...
difficult
...
to
...
measure
...
the
...
exact
...
buffer
...
size
...
of
...
each
...
hop
...
along
...
the
...
path.
...
We
...
can
...
somehow
...
easily
...
estimate
...
the
...
queing
...
delay
...
along
...
the
...
path
...
using
...
ping
...
and
...
traceroute
...
tools.
...
From
...
queing
...
delay,
...
we
...
can
...
estimate
...
congestion,
...
buffer
...
overflow,incoming
...
and
...
outgoing
...
data
...
rate.
...
If
...
we
...
take
...
the
...
difference
...
of
...
incoming
...
and
...
outgoing
...
datarate
...
that
...
will
...
give
...
us
...
the
...
queue
...
occupancy.
...
From
...
queue
...
occupancy,
...
we
...
can
...
roughly
...
estimate
...
the
...
buffer
...
size
...
of
...
that
...
specific
...
router.
...
In
...
the
...
following
...
sections,
...
I
...
am
...
going
...
to
...
explain
...
how
...
we
...
can
...
measure
...
the
...
average
...
queing
...
delay
...
using
...
ping,
...
and
...
queing
...
delay
...
at
...
each
...
and
...
every
...
hop
...
along
...
the
...
path
...
using
...
traceroute.
...
Ping and Delays:
In a network world, ping basically helps us to measure round trip time(RTT)
...
from
...
source
...
to
...
destination
...
using
...
ICMP
...
Echo
...
Messages.
...
It
...
doesn't
...
provide,
...
what
...
path
...
the
...
packet
...
takes
...
to
...
each
...
router
...
and
...
the
...
no.
...
of
...
routers
...
the
...
packet
...
have
...
traversed.
...
Normally
...
network
...
engineers
...
provides
...
the
...
no.
...
of
...
attempts
...
e.g.
...
10
...
in
...
PingER
...
for
...
each
...
probe.
...
From
...
these
...
10
...
attempts,
...
they
...
measure
...
four
...
different
...
metrics.
...
Min
...
Rtt,
...
Max
...
RTT,
...
Avr
...
RTT
...
and
...
Packet
...
loss.
...
Using
...
these
...
metrics,
...
we
...
can
...
measure
...
the
...
average
...
queing
...
delay
...
along
...
the
...
whole
...
path
...
by
...
subtracting
...
MaxRTT
...
from
...
MinRTT.
...
Lets
...
L
...
=
...
size
...
of
...
the
...
packet
...
and
...
R
...
=
...
data
...
rate
...
of
...
the
...
whole
...
path.
...
Average QD=
...
MaxRTT
...
-
...
MinRTT.
...
Average
...
TD
...
=
...
L/R
...
It
...
is
...
practically,
...
impossible
...
to
...
get
...
a
...
very
...
good
...
estimate
...
of
...
Queing
...
delay
...
at
...
each
...
hop
...
along
...
the
...
path
...
using
...
ping.
...
Traceroute
...
and
...
Delays:
...
Traceroute basically provides us with following metrics:
- No. of hops from source to destination
- IP and names of hops.
- Three times measured RTTs from source to each hop along the path.
In my own personal point of view, we can measure a good estimate of buffer size at each hop using traceroute measurement. The following sections describe the steps to figure out estimate of buffer size at each hop.
Lets say we have two hops(R1,R2)
...
between
...
source
...
A
...
and
...
destination
...
B.
...
Traceroute
...
measure
...
three
...
different
...
RTts
...
from
...
A
...
to
...
R1
...
and
...
R2
...
respectively.
...
and
...
lets
...
denote
...
those
...
rtts
...
by
...
(RTT1,
...
RTT2,
...
RTT3
...
) for
...
R1
...
and
...
(RTT1,
...
RTT2,RTT3
...
) for
...
R2
...
Now
...
get
...
the
...
Max
...
and
...
min
...
rtt
...
from
...
the
...
two
...
sets
...
separately.
...
and
...
denote
...
it
...
minRTT1,
...
maxRTT1
...
for
...
R1
...
and
...
minRTT2
...
and
...
maxRTT2
...
for
...
R2.
...
It
...
is
...
simple
...
to
...
find
...
queing
...
delay
...
at
...
R1
...
which
...
is:
...
Queing
...
Delay
...
at
...
R1
...
(QD1)
...
=
...
maxRTT1
...
-
...
minRTT1
...
As
...
the
...
packet
...
goes,
...
the
...
latency
...
from
...
A
...
to
...
R2
...
is
...
mainly
...
affected
...
by
...
the
...
queing
...
delay
...
of
...
R1.
...
Hence
...
we
...
need
...
to
...
subtract
...
the
...
queing
...
delay
...
at
...
R1
...
from
...
the
...
difference
...
of
...
maxRTT2
...
and
...
minRTT2.
...
Queing
...
Delay
...
at
...
R2
...
(Qd2)
...
=
...
maxRTT2
...
-
...
minRTT2
...
-
...
Qd1
...