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Spatio-Temporal Available

Bandwidth Estimation

Vinay RibeiroRolf Riedi, Richard Baraniuk

Rice University

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Network Path Model

Packet delay = constant term

  (propagation,

service time !

variable term

  ("ueuing delay

# $nd%to%end paths

& Multi%hop

& No packet reordering# Router "ueues

& '')

& *onstant service rate

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+ey efinitions

ii

 B A min=

# Goal-  use end%to%end pro.ing to locatetight link in space and over time

Path availa.le .andwidth

/u.%path availa.le .andwidth

0ight link- link with least availa.le .andwidth

imi

 Bm A≤≤

=1

min],1[

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1pplications

# Network monitoring  % locating hot spots

# Network aware applications% server selection

# /cience- where do nternet tight links occurand why 2

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Methodology

# $stimate A[1,m]

# 'or m3tight link, A[1,m] remains constant

imi Bm A

≤≤

=1min],1[

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Principle of /elf%nduced *ongestion

# Pro.ing rate = R, path availa.le .andwidth = A

# 1dvantages

& No topology information re"uired

& Ro.ust to multiple .ottlenecks

  R < A  no delay increase

  R > A  delay increases

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Packet 0ailgating

# 4arge packets of si5e P  (004=msmall packets of si5e p

# 4arge packets e6it at hop m

# /mall packets reach receiver with timing information

# Previously employed in capacity estimation

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$stimating A[1,m]

# +ey- Pro.ing rate decreases .y p/(p+P) at link m

# 1ssumption- r<A[m+1,N], no delay change after link

m 

R < A[1,m] no delay increase

  R > A[1,m]  delay increases

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0ight 4ink 4ocali5ation

# Tight in! - link after which A[1,m] remains constant

# 1pplica.le to any self%induced congestion tool-pathload, path*hirp, 7, netest etc8

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path*hirp

# *hirps- e6ponentially spaced packets

# 9ide range of pro.ing rates

# $fficient- few packets 

100Mbps-1  packets,134.1   ⇒=γ  

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ns%: /imulation

# ;eterogeneous sources

# 0ight link location changes over time

# path*hirp tracks tight link location change accurately

  t   i  g   h  t   l   i  n   k

  e  s  t   i  m  a  t  e

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nternet $6periment

#0wo paths-UU* Rice and /41*Rice

# Paths share < common links

# /ame tight link estimate

  for .oth paths

/41*Rice tight link

UU*Rice tight link

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*omparison with MR07 ata

#  A[1,m] decreases as e6pected

# 0ight link location differs from MR07 data .y hop

/41*Rice UU*Rice

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;igh /peed Pro.ing

# "y#tem $/% imit# probing rate# )n high speed networks-   cannot estimate A using

self%induced congestion

),min(d  s

  B B A >

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Receiver /ystem >) 4imitation

# 0reat receiver >) .us as an e6tra link

# Use packet tailgating

# f then we can estimate A[1,N&1]d  Br  <

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/ender /ystem >) 4imitations

# *om.ine sources to increase net pro.ing rate

# ssue- machine synchroni5ation

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*onclusions

# 0owards spatio%temporal availa.le .andwidthestimation

# *om.ine self%induced congestion and

packet tailgating

# 0ight link locali5ation in space and over time

# ns%: and nternet e6periments encouraging

# /olutions to system >) .andwidth limitations

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