指導教授 : 吳和庭 博士 研究生: 簡睿毅 日期 : 2005 / 7 / 15
DESCRIPTION
乙太被動式光學網路上能支援多媒體 服務 之動態頻寬配置機制 Dy namic Bandwidth Allocation Mechanisms for Multimedia Services on EPON. 指導教授 : 吳和庭 博士 研究生: 簡睿毅 日期 : 2005 / 7 / 15. Outline. Background Passive Optical Network (PON) Ethernet Passive Optical Network (EPON) Multi-Point Control Protocol (MPCP) Motivation - PowerPoint PPT PresentationTRANSCRIPT
乙太被動式光學網路上能支援多媒體服務之動態頻寬配置機制Dynamic Bandwidth Allocation Mechanisms for Multimedia Services on EPON
指導教授 : 吳和庭 博士研究生:簡睿毅日期 : 2005 / 7 / 15
Outline
Background Passive Optical Network (PON) Ethernet Passive Optical Network (EPON) Multi-Point Control Protocol (MPCP)
Motivation Dynamic Bandwidth Allocation Scheme
IPACT & DBAM DBA with QoS
Simulation Result Conclusion & Future Work
Background
The first mile still remains the bottleneck between high-capacity Local Area Networks (LANs) and the backbone network
A new technology is required to an end-user over a single network Inexpensive , Simple , Scalable Delivering bundled voice , data , video services
Passive Optical Network ( PON )
A point-to-multipoint optical network Two primary types of PON technologies
ATM PONEPON
PON Topology
Ethernet Passive Optical Network
EPON started to be standardized by IEEE
802.3ah EFM since 2001(2004 July done) Ethernet is a ubiquitous technology
Deployed widely in LAN, MAN and WAN
Ethernet is more attractive to PON than ATM High speed - up to 10 Gigabit/s Lower cost Easier interoperability
EPON Architecture
Features of EPON
All data packets carried in EPON are encap
sulated in Ethernet frames Broadcasting in the downstream direction fr
om the OLT to ONUs Sharing the upstream channel capacity amo
ng ONUs
That is the problem !
Multi-Point Control Protocol
The Multi-Point Control Protocol (MPCP) specifies a control mechanism between a Master unit and Slaves units connected to a Point-to-Multi-Point (P2MP) segment to allow efficient transmission of data
MPCP is implemented in MAC Control layer MPCP uses five MAC Control messages
GATE, REPORT, REGISTER_REQ, REGISTER, and REGISTER_ACK
Motivation
A dynamic bandwidth allocation scheme with a credit mechanism which can support QoS service and reduce packet delay
Dynamic Bandwidth Allocation Scheme
IPACT Interleaved Polling with Adaptive Cycle Time
DBAM Dynamic Bandwidth Allocation with Multiple Services
DBA with QoS Dynamic Bandwidth Allocation with QoS
IPACT Operation Step (1/4)
IPACT Operation Step (2/4)
IPACT Operation Step (3/4)
IPACT Operation Step (4/4)
Definition (1)
EF Expedited Forwarding , High Priority
AF Assured Forwarding , Medium Priority
BE Best Effort , Low Priority
Definition (2)
The maximum bandwidth parameter of a specific class of traffic is determined by the SLA between the
end user and service provider
the amount of data queued up in the buffer
is the requested bandwidth for class c traffic
the estimation credit
EF AF BEi i i iS S S S
EF AF BEi i i iR R R R
(1 )* , { , , }c ci iC R c EF AF BE EF AF BE
i i i iC C C C
, ,/i in waiting n cycleT T
ciC
Waiting Time & Cycle Time
DBAM Operation
EF AF BEi i i iC C C C
(1 )* , { , , }c ci iC R c EF AF BE
iC m in{ , }i i iB C S
, 1 , 1min{ , }, { , }c c ci n i n iB C S c EF AF
, 1 , 1 , 1 , 1BE EF AFi n i n i n i nB B B B
DBAM Case
, 1 , 1min{ , }, { , }c c ci n i n iB C S c EF AF
SLA SiEF:20 AF:30 BE:50
Request RiEF:60 AF:20 BE:20
Credit CiEF:70 AF:25 BE:25
EF:20 AF:25
EF:20 AF:25 BE:55, 1 , 1 , 1 , 1
BE EF AFi n i n i n i nB B B B
Assign Bandwidth = 100
min{ , }i i iB C S
Definitions
Actual queue size when transmission start
Finally guarantee bandwidth
EF AF BEi i i iA A A A
iS iR iC
EF AF BEi i i iG G G G
Waiting Time & Cycle Time
DBA with QoS Operation(1/2)
EF AF BEi i i iR R R R
(1 )*c ci iC R min{ , }i iBi C S
Bi
DBA with QoS Operation(2/2)
min{ , }, { , , }c c ci i iG S R c EF AF BE
min{ , , }c c c c c c ci i i i i i iG C G A G S G
min{ , }c c c c ci i i i iG C G A G
max{ , }c c c c ci i i i iG C G A G
DBA with QoS CaseSLA Si
EF:20 AF:30 BE:50
Request RiEF:60 AF:20 BE:20
Credit CiEF:70 AF:25 BE:25
Assign Bandwidth = 100
min{ , }i i iB C SEF:20 AF:20 BE:20
min{ , }, { , , }c c ci i iG S R c EF AF BE
Actual Queue Request AiEF:65 AF:30 BE:25
min{ , ,max{ ,0}}c c c c c ci i i i i iC G A G S G
GiEF:20 AF:20 BE:20
GiEF:20 AF:25 BE:25
min{ , }c c c ci i i iC G A G
GiEF:50 AF:25 BE:25
Request RiEF:60 AF:20 BE:20
DBAM GiEF:20 AF:25 BE:55
Simulation ModelEPON的系統頻寬 1Gbps
ONU個數 16
封包大小 64~1518 Bytes
佇列大小 1 Mbytes
模擬時間 1秒
系統負載 (Normalized Offer Load)
0~2
SLA比例 EF-20% AF-30% BE-50%
封包產生方式 Poisson
Simulated Result (1)
Load: EF-80% AF-10% BE-10%
00.050.1
0.150.2
0.250.3
0 0.5 1 1.5 2
Traffic Load
Ave
rage
EF
Pack
et D
elay
(s)
DBAM
DBA With QoS
IPACT
IPACT with Credit
Simulated Result (2)
Load: EF-80% AF-10% BE-10%
0
0.05
0.1
0.15
0.2
0 0.5 1 1.5 2
Traffic Load
Ave
rage
AF
Pack
et D
elay
(s)
DBAM
DBA With QoS
IPACT
IPACT with Credit
Simulated Result (3)
Load: EF-80% AF-10% BE-10%
0
0.05
0.1
0.15
0.2
0 0.5 1 1.5 2
Traffic Load
Ave
rage
BE
Pack
et D
elay
(s)
DBAM
DBA With QoS
IPACT
IPACT with Credit
Simulated Result (4)
DBA with QoS
00.020.040.060.080.1
0.12
0 0.5 1 1.5 2
Traffic Load
Ave
rage
Pac
ket D
elay
(s)
Load: EF-20% AF-30% BE-50%
Load: EF-80% AF-10% BE-10%
Load: EF-10% AF-80% BE-10%
Load: EF-10% AF-10% BE-80%
Simulated Result (5)
DBAM
0
0.05
0.1
0.15
0.2
0.25
0 0.5 1 1.5 2
Traffic Load
Ave
rage
Pac
ket D
elay
(s)
Load: EF-20% AF-30% BE-50%
Load: EF-80% AF-10% BE-10%
Load: EF-10% AF-80% BE-10%
Load: EF-10% AF-10% BE-80%
Credit Consideration
1, * *( / ), { , , }c c i ci i n waiting i i iC R T dataRate S S c EF AF BE
Simulation Result (1)
Load: EF-80% AF-10% BE-10%
00.050.1
0.150.2
0.250.3
0 0.5 1 1.5 2
Traffic Load
Ave
rage
EF
Pack
et D
elay
(s)
DBAM
Credit_1
Credit_2
Simulation Result (2)
Load: EF-80% AF-10% BE-10%
00.020.040.060.080.1
0.12
0 0.5 1 1.5 2
Traffic Load
Ave
rage
AF
Pack
et D
elay
(s)
DBAM
Credit_1
Credit_2
Simulation Result (3)
Load: EF-80% AF-10% BE-10%
0
0.05
0.1
0.15
0 0.5 1 1.5 2
Traffic Load
Ave
rage
BE
Pack
etD
elay
(s) DBAM
Credit_1
Credit_2
Conclusion & Future Work
Proposed a dynamic bandwidth allocation scheme can support QoS and reduce the packet delay for Ethernet Passive Optical Network
Future Work : Credit consideration