swift: predictive fast reroute - sigcomm · 2017-10-27 · 3 1.0.2.0/24 600k 200.0.0.0/24 ... 2....
TRANSCRIPT
![Page 1: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/1.jpg)
SWIFT: Predictive Fast Reroute
Thomas HolterbachETH Zürich / CAIDA
Stefano VissicchioAlberto DainottiLaurent Vanbever
UCLondonCAIDA, UC San DiegoETH Zürich
Joint work with
SIGCOMM24th August 2017
swift.ethz.ch
1
![Page 2: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/2.jpg)
2.5 min
2
![Page 3: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/3.jpg)
2.5 min
worst-case convergence timeof a router upon an Internet failure
3
![Page 4: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/4.jpg)
Let’s consider first a simple example
R2R1Focus
R3
backupnext-hop
primarynext-hop
4
![Page 5: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/5.jpg)
R2R1Focus
R3
backupnext-hop
primarynext-hop
5
![Page 6: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/6.jpg)
R2R1Focus
R3
backupnext-hop
primarynext-hop
Phase #1
Learningabout the failure
Updatingforwarding entries
Phase #2
BGP convergenceis a two-phase process
6
![Page 7: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/7.jpg)
pos. prefix NH
1 1.0.0.0/24 22 1.0.1.0/24 23 1.0.2.0/24
600K 200.0.0.0/24
… … …
300K 2
… … …
100.0.0.0/24
R1’s forwarding table
Phase #1
Learningabout the failure
Updatingforwarding entries
Phase #2
2
2
R2R1Focus
R3
backupnext-hop
primarynext-hop
BGP convergenceis a two-phase process
7
![Page 8: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/8.jpg)
pos. prefix NH
1 1.0.0.0/24 32 1.0.1.0/24 23 1.0.2.0/24
600K 200.0.0.0/24
… … …
300K 2
… … …
100.0.0.0/24
R1’s forwarding table
Phase #1
Learningabout the failure
Updatingforwarding entries
Phase #2
2
2
R2R1Focus
R3
backupnext-hop
primarynext-hop
BGP convergenceis a two-phase process
8
![Page 9: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/9.jpg)
pos. prefix NH
1 1.0.0.0/24 32 1.0.1.0/24 33 1.0.2.0/24
600K 200.0.0.0/24
… … …
300K 2
… … …
100.0.0.0/24
R1’s forwarding table
Phase #1
Learningabout the failure
Updatingforwarding entries
Phase #2
2
2
R2R1Focus
R3
backupnext-hop
primarynext-hop
BGP convergenceis a two-phase process
9
![Page 10: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/10.jpg)
pos. prefix NH
1 1.0.0.0/24 32 1.0.1.0/24 33 1.0.2.0/24
600K 200.0.0.0/24
… … …
300K 2
… … …
100.0.0.0/24
R1’s forwarding table
Phase #1
Learningabout the failure
Updatingforwarding entries
Phase #2
3
2
R2R1Focus
R3
backupnext-hop
primarynext-hop
BGP convergenceis a two-phase process
10
![Page 11: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/11.jpg)
pos. prefix NH
1 1.0.0.0/24 32 1.0.1.0/24 33 1.0.2.0/24
600K 200.0.0.0/24
… … …
300K 3
… … …
100.0.0.0/24
R1’s forwarding table
Phase #1
Learningabout the failure
Updatingforwarding entries
Phase #2
3
2
R2R1Focus
R3
backupnext-hop
primarynext-hop
BGP convergenceis a two-phase process
11
![Page 12: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/12.jpg)
pos. prefix NH
1 1.0.0.0/24 32 1.0.1.0/24 33 1.0.2.0/24
600K 200.0.0.0/24
… … …
300K 3
… … …
100.0.0.0/24
R1’s forwarding table
Phase #1
Learningabout the failure
Updatingforwarding entries
Phase #2
3
3R2R1
Focus
R3
backupnext-hop
primarynext-hop
BGP convergenceis a two-phase process
12
![Page 13: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/13.jpg)
13
![Page 14: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/14.jpg)
Phase #1
Learningabout the failure
Updatingforwarding entries
Phase #2
BGP timersBFD, …
PICMPLS, …
In practice, multiple techniques are often usedto speed up the convergence time
14
![Page 15: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/15.jpg)
none of them workupon remote outages
15
![Page 16: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/16.jpg)
remotefailure
R2R1Focus
R3
backupnext-hop
primarynext-hop
Current fast reroute techniquesdo not work upon remote outages
R4
BGPwithdrawals
16
![Page 17: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/17.jpg)
Remote outages are numerous
17
![Page 18: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/18.jpg)
Remote outages are numerous
We analyzed BGP sessions from RouteViews and RIPE RIS collectors, and looked for bursts of BGP withdrawals
18
![Page 19: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/19.jpg)
10 seconds sliding window
Remote outages are numerous
Time
# withdrawals
We analyzed BGP sessions from RouteViews and RIPE RIS collectors, and looked for bursts of BGP withdrawals
19
![Page 20: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/20.jpg)
10 seconds sliding window
Remote outages are numerous
Time
# withdrawals
We analyzed BGP sessions from RouteViews and RIPE RIS collectors, and looked for bursts of BGP withdrawals
20
![Page 21: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/21.jpg)
10 seconds sliding window
burst
Remote outages are numerous
Time
# withdrawals
We analyzed BGP sessions from RouteViews and RIPE RIS collectors, and looked for bursts of BGP withdrawals
21
![Page 22: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/22.jpg)
We found ~3,000 bursts of withdrawals in November 2016 and on 213 BGP sessions
Remote outages are numerous
We analyzed BGP sessions from RouteViews and RIPE RIS collectors, and looked for bursts of BGP withdrawals
22
![Page 23: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/23.jpg)
20 40 60 80
Burst durDtion (s)
0.0
0.2
0.4
0.6
0.8
1.0C
D)
Bursts lower thDn 10k
Bursts greDter thDn 10k
CDF
Burst duration (s)
Remote outages propagate slowly
23
![Page 24: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/24.jpg)
20 40 60 80
Burst durDtion (s)
0.0
0.2
0.4
0.6
0.8
1.0C
D)
Bursts lower thDn 10k
Bursts greDter thDn 10k
CDF
Burst duration (s)
Remote outages propagate slowly
24
![Page 25: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/25.jpg)
20 40 60 80
Burst durDtion (s)
0.0
0.2
0.4
0.6
0.8
1.0C
D)
Bursts lower thDn 10k
Bursts greDter thDn 10k
CDF
Burst duration (s)
37% last more than 10s
Remote outages propagate slowly
25
![Page 26: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/26.jpg)
Remote outages result in downtime
26
![Page 27: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/27.jpg)
Remote outages result in downtime
Time (s)
0 20 40 60 80 100 120 140Time (s)
0
20
40
60
80
100
Pack
et lo
ss (%
)
Failu
rePacket loss (%)
27
![Page 28: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/28.jpg)
Remote outages result in downtime
0 20 40 60 80 100 120 140Time (s)
0
20
40
60
80
100
Pack
et lo
ss (%
)
Failu
rePacket loss (%)
Time (s)
28
![Page 29: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/29.jpg)
Remote outages result in downtime
0 20 40 60 80 100 120 140Time (s)
0
20
40
60
80
100
Pack
et lo
ss (%
)
Failu
rePacket loss (%)
Time (s)
110s
29
![Page 30: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/30.jpg)
SWIFT: Predictive Fast Reroute Framework
30
![Page 31: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/31.jpg)
SWIFT: Predictive Fast Reroute Framework
works upon remote (and local) outages
31
![Page 32: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/32.jpg)
1. SWIFT reduces the learning time of a withdrawal from 13s to 2s using a control-plane prediction algorithm
SWIFT: Predictive Fast Reroute
32
![Page 33: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/33.jpg)
1. SWIFT reduces the learning time of a withdrawal from 13s to 2s using a control-plane prediction algorithm
2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a hierarchical forwarding table
SWIFT: Predictive Fast Reroute
33
![Page 34: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/34.jpg)
1. SWIFT reduces the learning time of a withdrawal from 13s to 2s using a control-plane prediction algorithm
2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a hierarchical forwarding table
3. SWIFT is deployable on existing routers
SWIFT: Predictive Fast Reroute
34
![Page 35: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/35.jpg)
1. SWIFT reduces the learning time of a withdrawal from 13s to 2s using a control-plane prediction algorithm
2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a hierarchical forwarding table
3. SWIFT is deployable on existing routers
SWIFT: Predictive Fast Reroute
35
![Page 36: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/36.jpg)
SWIFT predicts the extent of an outageusing fast, yet precise Root Cause Analysis
36
![Page 37: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/37.jpg)
37
Existing RCA techniques *
accuracy
# vantage points
detection speed
Lifeguard, SIGCOMM’14 Poiroot, SIGCOMM’13Feldmann et al., SIGCOMM’04
*
![Page 38: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/38.jpg)
38
Existing RCA techniques *
link/AS
multiple
O(minute)
Lifeguard, SIGCOMM’14 Poiroot, SIGCOMM’13Feldmann et al., SIGCOMM’04
*
accuracy
# vantage points
detection speed
![Page 39: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/39.jpg)
39
region
1
O(second)
SWIFTExisting RCA techniques *
link/AS
multiple
O(minute)
Lifeguard, SIGCOMM’14 Poiroot, SIGCOMM’13Feldmann et al., SIGCOMM’04
*
accuracy
# vantage points
detection speed
![Page 40: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/40.jpg)
21 5 6
7
8
3
40
![Page 41: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/41.jpg)
21 5 6
7
8
3
SWIFT
41
![Page 42: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/42.jpg)
21 5 6
7
8
3
SWIFT
10k prefixes
10k prefixes
1k prefixes
42
![Page 43: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/43.jpg)
21 5 6
7
8
3
SWIFT
10k prefixes
10k prefixes
1k prefixes
43
![Page 44: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/44.jpg)
21 5 6
7
8
3
SWIFT
1k prefixesUPDATES orWITHDRAWALS
10k prefixes
10k prefixes
44
![Page 45: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/45.jpg)
monitor the stream of BGP messages
Time
# withdrawals
#1
45
![Page 46: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/46.jpg)
detect and locate the outage
(A,B) 0.3
(A,D) 0.9
… …
monitor the stream of BGP messages
Time
# withdrawals
Links failure probability
#1
#2
Link (A,D) is dead
46
![Page 47: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/47.jpg)
detect and locate the outage
(A,B) 0.3
(A,D) 0.9
… … Link (A,D) is dead
predict future withdrawals
monitor the stream of BGP messages
Time
# withdrawals
predicted
Links failure probability
#1
#2
#3
47
![Page 48: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/48.jpg)
21 5 6
7
8
3
SWIFT
UPDATES orWITHDRAWALS
10k prefixes
10k prefixes
SWIFT link failure inference algorithmleverages the affected and unaffected prefixes
1k prefixes
48
![Page 49: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/49.jpg)
21 5 6
7
8
3
SWIFT
10k prefixes
10k prefixes
candidates set
(2,5) (5,6) (6,7) (6,8)AS links
1k prefixes
49
![Page 50: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/50.jpg)
21 5 6
7
8
3
SWIFT
10k prefixes
10k prefixes
candidates set
(2,5) (5,6) (6,7) (6,8)
(2,5) (5,6) (6,7) (6,8)
affected prefixes
candidates set
(2,5) (5,6) (6,7) (6,8)AS links
1k prefixes
from AS7
50
![Page 51: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/51.jpg)
21 5 6
7
8
3
SWIFT
10k prefixes
10k prefixes
from AS7 (2,5) (5,6) (6,7) (6,8)
from AS8 (2,5) (5,6) (6,7) (6,8)
affected prefixes
candidates set
(2,5) (5,6) (6,7) (6,8)
candidates set
(2,5) (5,6) (6,7) (6,8)AS links
1k prefixes
51
![Page 52: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/52.jpg)
(2,5) (5,6) (6,7) (6,8)
21 5 6
7
8
3
SWIFT
10k prefixes
10k prefixes
from AS7 (2,5) (5,6) (6,7) (6,8)
from AS8 (2,5) (5,6) (6,7) (6,8)
affected prefixes
from AS5
unaffected prefixes
candidates set
(2,5) (5,6) (6,7) (6,8)
candidates set
(2,5) (5,6) (6,7) (6,8)AS links
1k prefixes
52
![Page 53: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/53.jpg)
21 5 6
7
8
3
SWIFT
10k prefixes
10k prefixes
(2,5) (5,6) (6,7) (6,8)
(2,5) (5,6) (6,7) (6,8)
affected prefixes
unaffected prefixes(2,5) (5,6) (6,7) (6,8)
is the failed link
candidates set
(2,5) (5,6) (6,7) (6,8)
candidates set
(2,5) (5,6) (6,7) (6,8)AS links
1k prefixes
from AS7
from AS8
from AS5
53
![Page 54: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/54.jpg)
In practice, SWIFT uses two metricsComputed on a per AS-link basis
Withdrawals share
WS (l, t)Path sharing
PS (l, t)
Fraction of withdrawals crossing link l
Proportion of prefixeswithdrawn on link l
54
![Page 55: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/55.jpg)
Withdrawals share
WS (l, t)Path sharing
PS (l, t)
Fraction of withdrawals crossing link l
Proportion of prefixeswithdrawn on link l
FS (l, t) = X
Fit Scorefor link l
In practice, SWIFT uses two metricsComputed on a per AS-link basis
55
![Page 56: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/56.jpg)
Theorem Under perfect conditions, SWIFT alwaysreturns a set of links including the failed link
56
![Page 57: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/57.jpg)
To be fast, we can’t wait for all the withdrawalsChallenge #1
Theorem Under perfect conditions, SWIFT alwaysreturns a set of links including the failed link
SWIFT runs the link inference early during the burst in order to predict future withdrawals
57
![Page 58: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/58.jpg)
To be fast, we can’t wait for all the withdrawalsChallenge #1
Theorem Under perfect conditions, SWIFT alwaysreturns a set of links including the failed link
SWIFT runs the link inference early during the burst in order to predict future withdrawals
An outage can affect multiple AS linksChallenge #2SWIFT link inference algorithm returns a set of links, all with a high fit score
58
![Page 59: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/59.jpg)
SWIFT link failure inference is accurate
False Positives Rate (%)
True Positives Rate (%)
59
![Page 60: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/60.jpg)
SWIFT link failure inference is accurate
False Positives Rate (%)
True Positives Rate (%)
60
![Page 61: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/61.jpg)
SWIFT link failure inference is accurate
False Positives Rate (%)
True Positives Rate (%)
to be avoided
61
![Page 62: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/62.jpg)
SWIFT link failure inference is accurate
False Positives Rate (%)
True Positives Rate (%)
unnecessary traffic shifts
62
![Page 63: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/63.jpg)
SWIFT link failure inference is accurate
False Positives Rate (%)
True Positives Rate (%)
BGP speed
63
![Page 64: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/64.jpg)
SWIFT link failure inference is accurate
False Positives Rate (%)
True Positives Rate (%)
fastconvergence
64
![Page 65: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/65.jpg)
SWIFT is much faster than BGP
learning time (median)
BGP SWIFT
13 sec
65
![Page 66: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/66.jpg)
SWIFT is much faster than BGP
learning time (median)
BGP SWIFT
2 sec13 sec
66
![Page 67: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/67.jpg)
1. SWIFT reduces the learning time of a withdrawal from 13s to 2s using a control-plane prediction algorithm
2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a hierarchical forwarding table
3. SWIFT is deployable on existing routers
SWIFT: Predictive Fast Reroute
67
![Page 68: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/68.jpg)
1. SWIFT reduces the learning time of a withdrawal from 13s to 2s using a control-plane prediction algorithm
2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a hierarchical forwarding table
3. SWIFT is deployable on existing routers
SWIFT: Predictive Fast Reroute
68
![Page 69: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/69.jpg)
Fast rerouting the traffic upon remote outageshas several challenges
69
![Page 70: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/70.jpg)
Fast rerouting the traffic upon remote outageshas several challenges
A remote outage can affect any set of prefixes
70
![Page 71: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/71.jpg)
Fast rerouting the traffic upon remote outageshas several challenges
A remote outage can affect any set of prefixes
A remote outage can affect backup paths
71
![Page 72: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/72.jpg)
Fast rerouting the traffic upon remote outageshas several challenges
A remote outage can affect any set of prefixes
and we want to be fast
A remote outage can affect backup paths
72
![Page 73: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/73.jpg)
pos. prefix Pointer
1 1.0.0.0/24 0x1112 1.0.1.0/24 0x111
600K 0x111
… … …
Mapping table
Pointer table
Pointer NH
0x1113 1.0.2.0/24 0x211
Hierarchical Forwarding
port 1
port 2
0x211 3
…
port 3
200.0.0.0/24
To solve these challenges,SWIFT relies on a hierarchical forwarding table
2
73
![Page 74: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/74.jpg)
pos. prefix Pointer
1 1.0.0.0/24 0x1112 1.0.1.0/24 0x111
600K 0x111
… … …
Mapping table
Pointer table
Pointer NH
0x1113 1.0.2.0/24 0x211
2
Hierarchical Forwarding
port 1
port 2
0x211 3
…
port 3
200.0.0.0/24
To solve these challenges,SWIFT relies on a hierarchical forwarding table
74
![Page 75: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/75.jpg)
pos. prefix Pointer
1 1.0.0.0/24 0x1112 1.0.1.0/24 0x111
600K 0x111
… … …
Mapping table
Pointer table
Pointer NH
0x1113 1.0.2.0/24 0x211
2
Hierarchical Forwarding
port 1
port 2
0x211 3
…
port 3
200.0.0.0/24
To solve these challenges,SWIFT relies on a hierarchical forwarding table
75
![Page 76: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/76.jpg)
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 3
SWIFT uses custom pointers
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
200.0.0.0/24
76
![Page 77: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/77.jpg)
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 3
A indicates aprimary next-hop
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
200.0.0.0/24
SWIFT uses custom pointers
77
![Page 78: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/78.jpg)
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 312
A indicates aprimary next-hop
0xA25BD0xEF12D
0xAFBC3
0xAFBC3 0xA****0xE****
200.0.0.0/24
SWIFT uses custom pointers
78
![Page 79: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/79.jpg)
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 3
indicates theAS path used
12
0xA25BD0xEF12D
0xAFBC3
0xAFBC3 0xA****0xE****
200.0.0.0/24
SWIFT uses custom pointers
79
![Page 80: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/80.jpg)
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 30xA*** 10xE*** 2
indicates this prefixis traversing link (5,6)
200.0.0.0/24
SWIFT uses custom pointers
80
![Page 81: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/81.jpg)
0xAFBC3
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 30xA*** 10xE*** 2
indicates this prefixis traversing link (6,7)
0xA25BD0xEF12D
0xAFBC3200.0.0.0/24
SWIFT uses custom pointers
81
![Page 82: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/82.jpg)
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 3
indicates theAS path used
12
0xA25BD0xEF12D
0xAFBC3
0xAFBC3 0xA****0xE****
200.0.0.0/24
SWIFT uses custom pointers
82
![Page 83: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/83.jpg)
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 3
fast reroutes the traffictraversing the link (5,6)
12
30xA25BD0xEF12D
0xAFBC3
0xAFBC3 0xA****0xE****
0x*F***
200.0.0.0/24
SWIFT uses custom pointers
83
![Page 84: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/84.jpg)
SWIFT reroutes the affected trafficto unaffected backup paths
21SWIFT
5 6
7
8
3
4
10k prefixes
10k prefixes
84
![Page 85: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/85.jpg)
21SWIFT
5 6
7
8
3
4
SWIFT reroutes the affected trafficto unaffected backup paths
BGP may use a disrupted backup path
10k prefixes
10k prefixes
85
![Page 86: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/86.jpg)
21SWIFT
5 6
7
8
3
4
SWIFT can bypassthe failure
BGP may use a disrupted backup path
SWIFT reroutes the affected trafficto unaffected backup paths
10k prefixes
10k prefixes
86
![Page 87: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/87.jpg)
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K 200.0.0.0/24
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 3
indicates thebackup next-hops
0xA**** 10xE**** 2
SWIFT encodes the next-hops in the pointers too
87
![Page 88: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/88.jpg)
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K 200.0.0.0/24
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 30xA**** 10xE**** 2
indicates the backup next-hopto use if (5,6) fails
SWIFT encodes the next-hops in the pointers too
88
![Page 89: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/89.jpg)
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K 200.0.0.0/24
… … …
Mapping table
Pointer table
Pointer NH
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 30xA**** 10xE**** 2
indicates the backup next-hopto use if (6,7) fails
SWIFT encodes the next-hops in the pointers too
89
![Page 90: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/90.jpg)
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K 200.0.0.0/24
… … …
Mapping table
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 3
Pointer table
Pointer NH
0xA**** 10xE**** 2
0x*F*3* 3
fast reroutes the traffictowards a valid backup path
SWIFT encodes the next-hops in the pointers too
90
![Page 91: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/91.jpg)
Pointers are data-plane tags with limited size
pointer
48 bits
91
![Page 92: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/92.jpg)
pointer
as-path encoding primary and backup next-hops
48 bits
Pointers are data-plane tags with limited size
92
![Page 93: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/93.jpg)
pointer
as-path encoding primary and backup next-hops
SWIFT only encodes themost important AS links
48 bits
Pointers are data-plane tags with limited size
93
![Page 94: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/94.jpg)
SWIFT as path encoding algorithm enables to reroutemost of the affected prefixes, with few bits only
94
![Page 95: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/95.jpg)
SWIFT as path encoding algorithm enables to reroutemost of the affected prefixes, with few bits only
95
![Page 96: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/96.jpg)
18
median is 99%
SWIFT as path encoding algorithm enables to reroutemost of the affected prefixes, with few bits only
96
![Page 97: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/97.jpg)
pointer
48 bits
as-path encoding primary and backup next-hops
18 bits 30 bits
Pointers are data-plane tags with limited size
97
![Page 98: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/98.jpg)
SWIFT requires less than 100 forwarding updatesto reroute (with 16 backups)
98
![Page 99: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/99.jpg)
SWIFT requires less than 100 forwarding updatesto reroute (with 16 backups)
40 ms
99
![Page 100: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/100.jpg)
1. SWIFT reduces the learning time of a withdrawal from 13s to 2s using a control-plane prediction algorithm
2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a hierarchical forwarding table
3. SWIFT is deployable on existing routers
100
SWIFT: Predictive Fast Reroute
![Page 101: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/101.jpg)
1. SWIFT reduces the learning time of a withdrawal from 13s to 2s using a control-plane prediction algorithm
2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a hierarchical forwarding table
3. SWIFT is deployable on existing routers
101
SWIFT: Predictive Fast Reroute
![Page 102: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/102.jpg)
SWIFT is deployable on existing routersequipped with a hierarchical forwarding table
102
![Page 103: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/103.jpg)
SWIFT is deployable on existing routersequipped with a hierarchical forwarding table
103
what if we don’t have one though?
![Page 104: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/104.jpg)
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K 200.0.0.0/24
… … …
Mapping table
3 1.0.2.0/24
Hierarchical Forwarding
port 1
port 2
port 3
Pointer table
Pointer NH
0xA*** 10xE*** 2
0x*F*3 3
104
![Page 105: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/105.jpg)
port 1
port 2
port 3
IP Router
SDN switch
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
pos. prefix Pointer
1 1.0.0.0/242 1.0.1.0/24
600K 200.0.0.0/24
… … …
3 1.0.2.0/24
Mapping table
NH
0xA*** 10xE*** 2
0x*F*3 3
Pointer table
Pointer
105
![Page 106: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/106.jpg)
Pointer tableport 1
port 2
port 3
IP Router
SDN switch
0xA25BD0xEF12D
0xAFBC3
0xAFBC3
pos. prefix
1 1.0.0.0/242 1.0.1.0/24
600K 200.0.0.0/24
… … …
3 1.0.2.0/24
Mapping table
NH
0xA*** 10xE*** 2
0x*F*3 3
Dest. MAC
Dest. MAC
106
![Page 107: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/107.jpg)
SWIFT controller
CiscoRouter
SDNswitch
107
![Page 108: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/108.jpg)
0 20 40 60 80 100 120 140Time (s)
0
20
40
60
80
100
Pack
et lo
ss (%
)
Failu
re
Time (s)
Packet loss (%)
108
![Page 109: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/109.jpg)
SWIFT reduces the convergence time from ~110s to 2s
0 20 40 60 80 100 120 140Time (s)
0
20
40
60
80
100
Pack
et lo
ss (%
)
Failu
re BGPSWIFT
Time (s)
Packet loss (%)
109
![Page 110: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/110.jpg)
0 20 40 60 80 100 120 140Time (s)
0
20
40
60
80
100
Pack
et lo
ss (%
)
Failu
re BGPSWIFT
Time (s)
Packet loss (%)
98% speed upimprovement
SWIFT reduces the convergence time from ~110s to 2s
110
![Page 111: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/111.jpg)
Speeds up the learning phase by predicting the control-plane85% accuracy early in the burst
Quickly fast reroutes the affected traffic to unaffected pathsfor 99% of the prefixes
Is deployable on existing routers98% speed up improvement
swift.ethz.ch (source code, VM + demo!)
SWIFT: Predictive Fast Reroute
111
![Page 112: SWIFT: Predictive Fast Reroute - SIGCOMM · 2017-10-27 · 3 1.0.2.0/24 600K 200.0.0.0/24 ... 2. SWIFT fast reroutes the affected traffic towards unaffected paths in 40ms using a](https://reader034.vdocuments.site/reader034/viewer/2022050604/5fab548d8a245b3f203cbc8c/html5/thumbnails/112.jpg)
SWIFT: Predictive Fast Reroute
Thomas HolterbachETH Zürich / CAIDA
Stefano VissicchioAlberto DainottiLaurent Vanbever
UCLondonCAIDA, UC San DiegoETH Zürich
Joint work with
SIGCOMM24th August 2017
swift.ethz.ch
112