A Study Of Cyclone Technology

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12 Νοε 2013 (πριν από 3 χρόνια και 5 μήνες)

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University Of Maryland

1

A Study Of Cyclone Technology

University Of Maryland

2

Table of Content


Overview


Contributions


The need for time
-
based resource management


Cyclone technology
-

basic idea


Description of a Cyclone network


Clock synchronization


Data movements


Connection management


Scheduling


Adaptation layer


Fault handling


Performance


Advantages and limitations


Open issues

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3


Current networking


event
-
based, on
-
demand resource allocation


best effort performance


New classes of traffic placing stringent requirements on the communications


Time
-
based resource management in a synchronous manner


End
-
to
-
end coordination among network components


no congestion, loss, jitter


better utilization of bandwidth


one byte header


reduced control messages


reduced routing information


well
-
suited network environment for traffic with stringent timing requirements



Overview

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4

Contributions


Time
-
based networking technology


components


protocols


operations


host interface


Time
-
based resource management


Alternate way of managing resources in networking


without requiring very accurate and highly synchronized clocks


without consuming significant amount of bandwidth for handling timing variability

University Of Maryland

5

Time
-
based Resource Management In Networking

link 1
link 2
node X
node
Y
node Z
A
B
C
D
t1

t2

t3

t4

t5

t6

t7

t8

t9

t10

A

B

Data Loss

t1

t2

t3

t4

t5

t6

t7

t8

t9

t10

A

B

Data Loss Prevention

Delay and Jitter

A

B

t1

t2

t3

t4

t9

t10

t5

t6

t7

t8

t11

t12

Delay and Jitter Control

A

B

t1

t2

t3

t4

t9

t10

t5

t6

t7

t8

t11

t12

University Of Maryland

6

Cyclone Technology
-

Basic Idea

t
A

t
A
+s
A

t
A
+2s
A

t
A
+3s
A

t
A
+
i
s
A

t
A
+(
i
-
1
)s
A

t
A
+(
i+1
)s
A

t
B

t
B
+s
B

t
B
+2s
B

t
B
+(
j
-
1
)s
B

t
B
+(
j+1
)s
B

t
B
+
j
s
B

. . .

. . .

t
A

t
A
+s
A

t
A
+d

t
A
+s
A
+d

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7

Data Movements
-

Basic

Incoming link

Outgoing link

Slot buffer

Pointer buffer

Free slot list

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8

Data Movements

controller

switch

host

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9

Types Of Traffic Supported


Connection
-
oriented


Scheduled traffic


data available at known time instant (temporal profile)


resources reserved when establishing a connection


On
-
demand traffic


source routing


dynamic resource allocation


possible loss of a chunk

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10

Description Of Cyclone Network


Chunk


Slot and slot time


Time tag


Period


Fixed design parameters


the size of a chunk


the duration of a period


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11

Chunk Types


Three types
-

Control/Scheduled/On
-
demand


Control chunk


multiple sub
-
chunks in a chunk


connection request chunk


confirm/reject/abort/terminate chunk


pathfinder chunk


Scheduled chunk


scheduled traffic data chunk


scheduled traffic data acknowledgement/retransmission request chunk


On
-
demand chunk


on
-
demand traffic data chunk


on
-
demand traffic data acknowledgement/retransmission request chunk

marker

checksum

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12

Multiple Sub
-
chunks In A Chunk

marker
n
subchunk
padding
subchunk
checksum
. . .
512 bytes
8 bit marker
8 bit n is the number of subchunks contained;
maximum is (512-1-1-2)/b
where b is the number of bytes in a subchunk (127)
b*n bit subchunks where b is the number of bits in a subchunk
v bit padding where (v=(512-1-1-b*n-2)*8>=0)
16 bit checksum
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13

Connection Request Chunk

8 bit marker
160 bit source address (128 bit address + 32 bit port)
160 bit destination address (128 bit address + 32 bit port)
8 bit type of services
64 bit start time
64 bit end time
16 bit s is the number of temporal descriptors in this chunk
24*sbit temporal behavior
v bit padding where (v=(512-1-20-20-1-8-8-2-3*s-2)*8>=0)
16 bit checksum
512 bytes
marker
ToS
source
destination
padding
temporal
behavior
checksum
start
end
s
8 bit marker
160 bit source address (128 bit address + 32 bit port)
160 bit destination address (128 bit address + 32 bit port)
16 bit s is the number of temporal descriptors in this chunk
24*sbit temporal behavior
v bit padding where (v=(512-1-20-20-2-3*s-2)*8>=0)
16 bit checksum
512 bytes
marker
source
destination
padding
temporal
behavior
checksum
s
University Of Maryland

14

Confirm/Reject/Abort/Terminate Chunk

8 bit marker
160 bit source address (128 bit address + 32 bit port)
160 bit destination address (128 bit address + 32 bit port)
672 bit padding (127-1-20-20-2)*2
16 bit checksum
marker
source
destination
padding
checksum
127 bytes
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15

Pathfinder Chunk

8 bit marker
160 bit source address (128 bit address + 32 bit port)
160 bit destination address (128 bit address + 32 bit port)
8 bit number of hops(h)*
8 bit pointer into current hop position**
8*h*2 bit list of outgoing and incoming link identifier pair at each hop*
v bit padding where (v=(127-1-20-20-1-1-1*h*2-2)*8>=0)*
16 bit checksum*
* recomputed at each hop on forward path
**recomputed at each hop on forward and reverse paths
marker
source
destination
list*
checksum*
hops*
padding*
127 bytes
pointer**
University Of Maryland

16

Scheduled Traffic Data and
Acknowledgement/Retransmission Request Chunk

8 bit chunk marker
8*d bit data (d bytes of data)
v bit padding where (v=(512-1-1*d-2)*8>=0)
16 bit checksum
data
marker
checksum
padding
512 bytes
8 bit marker
160 bit source address (128 bit address + 32 bit port)
160 bit destination address (128 bit address + 32 bit port)
16 bit slot sequence number for this connection
656 bit padding (127-1-20-20-2-2)*8
16 bit checksum
marker
source
destination
sequence
padding
checksum
127 bytes
University Of Maryland

17

On
-
Demand Traffic Data And
Acknowledgement/Retransmission Request Chunk

8 bit check marker
8 bit number of hops
8 bit index into current hop information
8*h*2 bit list of outgoing and incoming link identifier pair at each hop
160 bit source address
160 bit destination address
8*d bit data (d byte data)
v bit padding where (v=(512-1-1-1-1*h*2-20-20-1*d-2)*8>=0)
16 bit checksum*
* recomputed at each hop
marker
list
data
padding
checksum*
512 bytes
hop
pointer*
source
destination
8 bit marker
8 bit number of hops(h)
8 bit index into current hop information*
8*h*2 bit list of outgoing and incoming link identifier pair at each hop
160 bit source address (128 bit address + 32 bit port)
160 bit destination address (128 bit address + 32 bit port)
8*d bit data containing acknowledgement/retransmit request
v bit padding where (v=(127-1-1-1-1*h*2-20-20-1*d-2)*8>=0)
16 bit checksum*
* recomputed at each hop
marker
source
destination
list
checksum*
hops
padding
127 bytes
pointer*
data
University Of Maryland

18

Cyclone Network Model

Non-Cyclone
Network
Non-Cyclone Network
Temporal Regulator
Cyclonode
controller

switch

Incoming
link
1

Incoming
link
m

outgoing
link
1

outgoing
link
m

Backup
Incoming
link
1’

Backup
Incoming
link
m’

Backup
outgoing
link
1’

Backup
outgoing
link
m’

1’

m’

host

University Of Maryland

19

Clock Synchronization


Markers are sent to indicate the beginning and
ending of a period


A node obtains the clock information of
upstream nodes


A local clock rate is set to the average of
incoming clock rates and its own rate


A local clock phase is set considering clock
phase information

Clock Adjustment At A Node
With Four Incoming Links

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20

Connection Establishment/Termination

A

B

C

D

E

6

1

2

5

7

4

3

University Of Maryland

21

Time Relationship Of Scheduling

Timeline of incoming link

Timeline of outgoing link
(same speed)

d

Timeline of outgoing link
(slower)

Timeline of outgoing link
(faster)

t1

t2

t3

t4

t3

t3

t4

t4

4
2
3
1
t
t
t
t






d
University Of Maryland

22

Single
-
Pass Scheduling Approach

0

1

2

3

4

5

6

7

22

23

24

25

0

1

2

3

4

5

6

7

22

23

24

25

26

0

1

2

3

4

5

6

7

22

23

24

25

26

21

27

28

Available
slot list

(2, 3, 5, 6, 7)

(3, 6, 7)

(3)

(1, 3, 4, 5)


First available slot column assignment


Assignment before reusing the buffer space

University Of Maryland

23

Double
-
Pass Scheduling Approach

0

1

2

3

4

5

6

7

21

22

23

24

25

26

27

0

1

2

3

4

5

6

7

28

21

22

23

24

25

26

27

Available
slot list

(1, 2, 3, 4, 6)

(2, 3, 4)

0

1

2

3

4

5

6

7

28

21

22

23

24

25

26

27

Available
slot list

(1, 2, 3, 4, 6)

(2, 3, 4)

University Of Maryland

24

Double
-
Pass Scheduling Approach

0

1

2

3

4

5

6

7

21

22

23

24

25

26

27

0

1

2

3

4

5

6

7

28

21

22

23

24

25

26

27

Available
slot list

(1, 2, 3, 4, 6)

(2, 3, 4)

University Of Maryland

25

Adaptation Layer


Receive information from an application
and provide the appropriate information
to a temporal regulator in the form
acceptable to a Cyclone network


Specify temporal profile for a scheduled
traffic


Provide scheduled data chunks according
to the temporal profile specified


Detect bit
-
errors


Initiate appropriate recovery mechanisms


Initiate command control chunks


Detect data loss for on
-
demand traffic


Supports existing applications and
communications with non
-
Cyclone
networks


Application Layer
Cyclone Adaptation Layer Application Interface (CAL-A)
Cyclone Adaptation Layer Cyclone Interface (CAL-C)
Switch
Controller
Host
Temporal Regulator
Application Layer
CAL-A
CAL-C
Switch
Controller
Host
Temporal Regulator
TCP
IP
Network
Interface
University Of Maryland

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Fault Handling


Backup link approach


line condition monitor


backup link pointer


automatic switching to backup


Application
-
dependent recovery
mechanism


primary and secondary connections


altering partial or entirety of a path


Reader
-
writer flag for handling
timing variability

slot buffer
pointer buffer
free slot list
marker checker
incoming
link
1
backup
incoming
link 4
backup
outgoing
link 3
outgoing
link
1
controller
next free slot
pointer
switch
line condition monitor
3
incoming
link 2
outgoing
link 2
backup
incoming
link 3
backup
outgoing
link 4
4
backup link
pointer
backup link
pointer
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Summary Of Scheduling Techniques

Cyclone
Stop-and-Go
Jitter-EDD
WFQ
Bounded Delay
Y
Y
Y
Y
Bounded Jitter
Y
Y
Y
N
Bandwidth
Protection
Y
Y
Y
Y
Advantages
Provides bounded delay and jitter
No additional operations during
data transmission.
No header.
Easy hardware implementation
Provides bounded
delay and jitter
Bounded buffer
requirement
Provides bounded
delay and jitter
Bounded buffer
requirement
Smoothes bursts without
policing
Disadvantages
Clock synchronization
Explicit resource reservations
Coupled delay bound
and bandwidth
allocation
To reduce delay jitter,
all packets received a
large delay
Complicate
implementation due to
separate regulator
Costly local delay
bound computation
Coupled delay bound
and bandwidth
allocation
Expensive round
number computation
E-to-E Delay
Bound
PH
N
m
N







HT
2
D (or
H
H
D
)




max
1
S
H


Jitter Bound
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Performance Studies


Data transfer


Connection admission


long term connections


single node and multiple nodes

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Type Of Traffic Studied


Regularly spaced traffic


Random pattern traffic

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30

Regularly Spaced Traffic (S5
-
S7)

0
20
40
60
80
100
120
1
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
93
97
number of trials
number of slots
(S5: 5-10%) 97.33% Loading
(S6: 10-20%) 94.32% Loading
(S7: 5-33%) 95.24% Loading
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31

0
20
40
60
80
100
120
1
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
93
97
number of trials
number of slots
number of additionally used slots after 15 requests
number of used slots before the first rejection
(S7) 98.1% Loading

trials 26-30 of (S7)
75
80
85
90
95
100
105
1
2
3
4
5
number of trials
number of slots
number of additionally used
slots after 15 requests
number of used slots before the
first rejection
University Of Maryland

32

Random Pattern (S8)

0
20
40
60
80
100
120
0
20
40
60
80
100
120
% of available slots requested
p(a)
d-avg
University Of Maryland

33

Random Pattern (S9)

0
10
20
30
40
50
60
70
80
90
100
0
20
40
60
80
100
120
% of available slots requested
p(a)
d-avg
University Of Maryland

34

Random Pattern (S10)

0
20
40
60
80
100
120
0
20
40
60
80
100
120
% of available slots requested
p(a)
d-avg
University Of Maryland

35

Random Pattern (S11)

0
20
40
60
80
100
120
0
20
40
60
80
100
120
% of available slots requested
p(a)
d-avg
University Of Maryland

36

Multiple Nodes


Multiplied probability


End
-
to
-
end delay is added

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37

Summary Of Performance Issues


A couple of millisecond per node connection establishment overhead


Close to 100% loading for identical, regularly spaced traffic


Above 90% loading for regularly spaced traffic


Above 80% loading for arbitrary pattern traffic, requesting 10% of bandwidth



More than 50% of acceptance when links are 80% loaded, requesting 10% of
bandwidth

University Of Maryland

38

Summary


Time
-
based resource management approach in networking


All aspects of a computer network required to support time
-
based resource
management


both scheduled and on
-
demand traffic


end
-
to
-
end resource usage scheduling in time


calendar
-
based data movements


existing applications and communications with non
-
Cyclone network


fault condition handling


The feasibility of Cyclone technology


end
-
to
-
end delay


connection establishment overhead


the probability of connection acceptance

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39

Advantages


Temporal determinacy


Loss free and jitter free end
-
to
-
end data delivery with minimal latency, without
sustaining significant delays in connection establishment


Nearly all of the bandwidth available for the actual transmission of data


High loading without having any adverse impact on performance


Well
-
suited for hardware implementation


Highly scalable

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40

Limitations


Temporal determinacy


temporal profile of a connection be known ahead


not current practice in networking


Handling applications with significant variability


Synchronous system

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41

Open Issues


Alternative designs and policies


Optimization of many system parameters


Design tradeoff and optimization for specific applications


Dynamic monitoring of performance


Support existing internetworking protocols other than TCP/IP


Extensions to point
-
to
-
point links and point
-
to
-
point connections


Hardware design

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42

Value Added


Time
-
based resource management


Alternate way of managing resources in networking


without requiring very accurate and highly synchronized clocks


without consuming significant amount of bandwidth for handling timing variability


Current applications with stringent timing requirement will perform better


Lead to development of new classes of applications that are possible only
when tight timing guarantee can be given


University Of Maryland

43

Pathfinder

D

1

S

3

checksum

padding

marker

S

D

0

0

4

2

2

7

1

1

12

15

2

2

3

3

4

15

6

4

4

4

4

2

2

7

7

12

12

15

15

6

6

4

4

15

15

University Of Maryland

44

Connection Establishment/Termination

A

B

C

D

E

6

1

2

5

7

4

3