05-06-2010, 09:51 AM
A Geometric Approach to Improving Active Packet
Loss Measurement
Measurement and estimation of packet loss characteristics
are challenging due to the relatively rare occurrence
and typically short duration of packet loss episodes.packet loss on end-toend
paths are measured by active
probe tools. But accuracy of these
tools or their impact on the network has not been probed.
DEFINITIONS OF LOSS CHARACTERISTICS
packet loss
in the Internet is contributed by many factors. The environment that we consider is modeled as
a set of N flows that pass through a router R and compete
for a single output page link with bandwidth Bout. The two
definitions for packet loss rate are:
-Router-centric loss rate:=L/(S+L)
L=number of dropped
packets on a given output page link on router R
S=the number of all successfully in a given time period
transmitted packets through the same page link over the same
period of time.
-End-to-end loss rate:
Here we only count packets that belong to a
specific flow of interest.
LABORATORY TESTBED
It consisted of commodity end hosts connected
to a dumbbell-like topology comprised of Cisco GSR 12000
routers.the end hosts generated and
received the probe and background traffic.
Traffic flowed from the sending
hosts on separate paths via Gigabit Ethernet to separate Cisco
GSRs. Probe and background traffic was then multiplexed onto a single page link where loss took place(bottleneck)
The probe and traffic generator hosts consisted of identically
configured workstations running Linux. the true loss
episode state (ground truth) for the experiments was generated by this testbed.
EVALUATION OF SIMPLE POISSON PROBING FOR
PACKET LOSS
the
capabilities of simple Poisson-modulated loss probe measurements was evaluated using the ZING tool. UDP probe packets at Poisson-modulated
intervals with timestamps and unique sequence numbers is emitted by the ZING sender. separate experiments were conducted to evaluate simple simple Poisson probing.
PROBE PROCESS MODEL
General Setup:
a sequence of
probes were despatched- each consisting of one or more very closely spaced
packets. The aim of a probe is to obtain a snapshot of the
state of the network at the instant of probing.
For more details refer this report pdf:
http://citeseerx.ist.psu.edu/viewdoc/dow...1&type=pdf
Loss Measurement
Measurement and estimation of packet loss characteristics
are challenging due to the relatively rare occurrence
and typically short duration of packet loss episodes.packet loss on end-toend
paths are measured by active
probe tools. But accuracy of these
tools or their impact on the network has not been probed.
DEFINITIONS OF LOSS CHARACTERISTICS
packet loss
in the Internet is contributed by many factors. The environment that we consider is modeled as
a set of N flows that pass through a router R and compete
for a single output page link with bandwidth Bout. The two
definitions for packet loss rate are:
-Router-centric loss rate:=L/(S+L)
L=number of dropped
packets on a given output page link on router R
S=the number of all successfully in a given time period
transmitted packets through the same page link over the same
period of time.
-End-to-end loss rate:
Here we only count packets that belong to a
specific flow of interest.
LABORATORY TESTBED
It consisted of commodity end hosts connected
to a dumbbell-like topology comprised of Cisco GSR 12000
routers.the end hosts generated and
received the probe and background traffic.
Traffic flowed from the sending
hosts on separate paths via Gigabit Ethernet to separate Cisco
GSRs. Probe and background traffic was then multiplexed onto a single page link where loss took place(bottleneck)
The probe and traffic generator hosts consisted of identically
configured workstations running Linux. the true loss
episode state (ground truth) for the experiments was generated by this testbed.
EVALUATION OF SIMPLE POISSON PROBING FOR
PACKET LOSS
the
capabilities of simple Poisson-modulated loss probe measurements was evaluated using the ZING tool. UDP probe packets at Poisson-modulated
intervals with timestamps and unique sequence numbers is emitted by the ZING sender. separate experiments were conducted to evaluate simple simple Poisson probing.
PROBE PROCESS MODEL
General Setup:
a sequence of
probes were despatched- each consisting of one or more very closely spaced
packets. The aim of a probe is to obtain a snapshot of the
state of the network at the instant of probing.
For more details refer this report pdf:
http://citeseerx.ist.psu.edu/viewdoc/dow...1&type=pdf