1 a fast delay-constrained multicast routing algorithm baoxian zhang; krunz, m.m.; changjia chen...
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1
A Fast Delay-Constrained Multicast Routing Algorithm
Baoxian Zhang; Krunz, M.M.; Changjia Chen
Communications, 2001. ICC 2001. IEEE International Conference on , Volume: 9 , 2001
Page(s): 2676 -2680
2
Outline
Motivation,model and problem SDCR heuristic for unicast DCMA heuristic for multicast Simulation results Conclusion
3
Motivation
Objective
– Construct a delay-constrained multicast tree with lower complexity
– DCMA heuristic : Earlier research
– BSMA heuristic :– KPP heuristic :– CKMB heuristic :
)log||( 3 VVkO
)||( 3VO )||( 2VmO
|)|log( VmmO
4
Model and Problem
Given – A network graph : G(V,E)– Each link has
• Delay value D(e)• Link cost C(e)
– Source node s– Destination set – Delay constraint
Ee
sVS
5
Model and Problem
Finda tree T rooted at s and span all nodes satisfying – – is minimum
)( GT
),()(
vsPeeD
TeeC )(
Sv
6
Routing information
Source routing strategy– Source maintain full information– OSPF is used
Two vectors – Delay vector– Cost vector– Each has |V|-1 entries for sVv j
7
Routing information (cont.)
Entry for in delay vector– Destination ID– End to end delay of least delay path– Predecessor of on
Entry for in cost vector – Destination ID– End to end delay of least cost path – Predecessor of on
jv
),( jld vsP
jv ),( jld vsP
jv
),( jlc vsP
),( jlc vsPjv
8
Outline
Motivation,model and problem SDCR heuristic for unicast DCMA heuristic for multicast Simulation results Conclusion
9
Source-based Delay Constrained Routing (SDCR)
Objective– Find a delay-constrained least cost path
between source and a destination Idea
– Start from d – Backward to s along until
•
– Then continues along until reach s
),( dsPld
)),(()),(( dvPDvsPD ldlc
),( vsPlc
10
Example of SDCR Heuristic
s
D
F
E
Destination : F
Each link has {cost,delay} pair
Delay constraint : 6
(1,3) (1,4)
(5,1) (3,1)
(3,1)
s
D
E
F s
D
F
ERelay node
(a) (b)
(a) SDCR
(b) LD path
11
SDCR Heuristic (cont.)
Complexity is O(|V|) Lemma
– SDCR returns a loop-free path Idea
– can not contain any node on ,besides relay node u
),( usPlc ),( duPld
s u v d
LD path
LC path
12
Outline
Motivation,model and problem SDCR heuristic for unicast DCMA heuristic for multicast Simulation results Conclusion
13
Delay Constrained Multicast Algorithm (DCMA)
Based on SDCR algorithm Earlier research
– Union of all delay-constrained unicast paths– Loop will happen
Loop phenomenon
s v
d2
d1
w
relay node of d1
u
relay node of d2LD path
LC path
14
Loop free DCMA Heuristic
Idea – First phase
• Proceed along path• Until a node v
– Marked or satisfy
– Second phase • Connect each v to s along• Until
– Reach s or a node on existing tree
),( dsPld
)),(()),(( dvPDvsPD ldlc
),( vsPlc
15
First Phase of DCMA Heuristic
while S is not empty active_node d remove d while ON[active_node]=0 if ON[active_node] ld_lhop active_node ld_lhop else Q[d]=active_node break
)),_(())_,(( dnodeactivePDnodeactivesPD ldlc
16
Second Phase of DCMA Heuristic
for i=1 to |S| if Q[i] NULL active_node = Q[i] while ON[active_node]=0 ON[active_node] lc_lhop active_node lc_lhop
17
Example of DCMA Heuristic
s
d1
d2v
uS = {d1,d2}Q[d1]=Q[d2]=u LD path LC path
relay node=Q[d1]
s
u
v
d1
d2
Final tree
18
DCMA Heuristic (cont.)
Lemma– The tree constructed by DCMA is always
loop-free Possible case for loop
– Source s,destination {x,y,z}
s
u
q
z
vx
y
s
u
q
z
v w
x
y
19
Outline
Motivation,model and problem SDCR heuristic for unicast DCMA heuristic for multicast Simulation results Conclusion
20
Simulation
Parameters – Link capacity with 155 Mbps– Cost
• Total reserved bandwidth
– Traffic• Uniform distributed 10M and 120Mbps
Performance evaluation• Cost of LD, DCMA, CDKS heuristics with
respect to CKMB
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Simulation Results
22
Outline
Motivation,model and problem SDCR heuristic for unicast DCMA heuristic for multicast Simulation results Conclusion
23
Conclusion
Complexity– SDCR : O(|V|)– DCMA : O(mlogm+|V|)
DCMA heuristic– achieve good performance and complexity
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