US 2026/0205365 A1 · METHOD FOR DEPLOYING SFC IN MULTI-DOMAIN NETWORK BASED ON VNF DEPENDENCY COMPONENT MIGRATION

Abstract

The present disclosure discloses a method for SFC deployment based on VNF-dependent software migration in a multi-domain network, and relates to the field of communications technologies. The method jointly optimizes the SFC deployment and the migration of VNF-dependent software to resolve issues concerning service provision in the multi-domain network. According to the method, information related to the multi-domain network is first initialized, and then a multi-layer network architecture is constructed to support SFC deployment. Then, a multi-layer weighted network is established by using an analytic hierarchy process (AHP), and an SFC deployment policy and a VNF-dependent software migration policy are executed on this basis. In the present disclosure, the impact between SFC deployment and VNF-dependent software migration decisions is comprehensively considered, achieving efficient SFC deployment and VNF-dependent software migration in the multi-domain network.

A method for service function chain (SFC) deployment based on virtualized network function (VNF)-dependent software migration in a multi-domain network, comprising:

(1) constructing a multi-domain network communication architecture based on a software-defined networking (SDN) controller, wherein the multi-domain network communication architecture comprises a multi-domain physical network, a terminal user, a domain-specific SDN controller, and a central SDN controller;
the terminal user initiates a service request to the domain-specific SDN controller;
the domain-specific SDN controller transmits information to a central SDN controller;
the central SDN controller issues an SFC deployment instruction and a VNF-dependent software migration instruction to the domain-specific SDN controller in conjunction with VNF-dependent software migration;
and the multi-domain network provides services for the terminal user according to a decision of the domain-specific SDN controller;
(2) establishing a network topology and a service request model, which specifically comprises:
(21) mapping a service function chain through a heterogeneous multi-domain physical network based on a multi-domain network topology, wherein
a domain set of the heterogeneous multi-domain physical network is represented as ={G1, G2, . . . , Gτ, . . . , G|G|}, wherein Gτ represents a τ-th network domain, |G| represents a number of domains, a multi-domain physical network node set is represented as Nτ={nτ1, nτ2, . . . , nτi, . . . , nτ|Nτ|}, nτi represents i-th node in the network domain τ, a physical network link set is represented as Eτ={eτi,τj|nτi,nτj∈Nτ}, the multi-domain network supports |K| types of VNFs and operates for a long period of time T={1, 2, . . . , t, . . . , |T|} to support provision of services requested by the user, and a node set N is used for deploying virtual machines to operate VNFs and forward data;
a maximum computing capability
ϕ
n
τ
⁢
i
c
,
a maximum memory capacity
ϕ
n
τ
⁢
i
m
,
and a maximum storage capacity
ϕ
n
τ
⁢
i
s
of each of server nodes are used to represent computing, memory, and storage resources of the server nodes, respectively, and each of the server nodes belongs to one sub-network;
a variable Onτi is defined to represent a domain to which a server node nτi, belongs, a link eτi,{circumflex over (τ)}j connects two server nodes nτi and n{circumflex over (τ)}j, representing a physical link therebetween;
when the network domain τ is equal to {circumflex over (τ)}, the physical link connection represents an intra-domain link, and otherwise, the link eτi,{circumflex over (τ)}j represents an inter-domain link;
neτi,{circumflex over (τ)}j,1 and neτi,{circumflex over (τ)}j,2 represent a starting node and an ending node of the link eτi,{circumflex over (τ)}j, respectively;
and beτi,{circumflex over (τ)}j is used to represent a bandwidth capacity of the link eτi,{circumflex over (τ)}j,
ϕ
^
n
τ
⁢
i
c
is used to represent remaining computing resources of the server node nτi,
ϕ
^
n
τ
⁢
i
m
represents remaining memory resources of the server node nτi,
ϕ
^
n
τ
⁢
i
s
is used to represent remaining storage resources of the server node nτi, and {circumflex over (b)}eτi,{circumflex over (τ)}j represents remaining bandwidth resources of the link eτi,{circumflex over (τ)}j;
(22) constructing the service request model, wherein
all user requests that enter a network function virtualization (NFV)-based multi-domain network and have actual demands are represented as SFC requests, an SFC request set is represented as Γ={Γ1, Γ2, . . . , Γr, . . . , Γ|Γ|}, and a 5-tuple {sr, dr, br, lr, Gr} is defined to represent an SFC request r, wherein sr,dr represent a source node and a target node, respectively, and each SFC request r has a known bandwidth demand br and a maximum tolerable end-to-end latency requirement lr;
and
the SFC request r consists of a group of predefined VNFs and links, wherein the VNFs represent more than one virtualized network function, and is represented as a directed weighted graph Gr={Fr,Er}, wherein Fr={ƒr1, ƒr2, . . . , ƒrh, . . . , ƒr|F|} represents a set of VNFs, and Er={ξƒrg,ƒrh|ƒrg,ƒrh∈Nr} represents a set of virtual network links;
and each VNF ƒrh∈Fr requires a certain amount of server computing resources
R
f
rh
c
and a certain amount of memory resources
R
f
rh
m
,
and similarly, bandwidth resources br need to be allocated for mapping a virtual link;
(23) constructing a VNF-dependent software migration model, configured to migrate software from one server node to another server node, wherein
when the VNF ƒrh is decided to be deployed on the server node nτi with insufficient software resources, related dependent software of the VNF ƒrh is migrated to the server node nτi;
and Ψ={Ψ1, Ψ2, . . . , Ψq, . . . , Ψ|Ψ|} represents a set of all software resources supporting operation of the VNF ƒrh;
and
for VNF placement and logical link mapping, two binary decision variables are used to define this relationship:
x
f
rh
n
τ
⁢
i
=
{
1
,
f
rh
⁢
is
⁢
placed
⁢
on
⁢
node
⁢
n
τ
⁢
i
,
0
,
otherwise
.
(
1
)
y
ξ
f
rg
,
f
rh
e
τ
⁢
i
,
τ
^
⁢
j
=
{
1
,
ξ
f
rg
,
f
rh
⁢
is
⁢
mapped
⁢
on
⁢
link
⁢
e
τ
⁢
i
,
τ
^
⁢
j
,
0
,
otherwise
.
(
2
)
wherein a logical link ξƒrg,ƒrh is able to be mapped to a plurality of physical links, indicating that communication between VNFs is able to span a plurality of physical connections;
and
(24) a VNF-dependent software migration decision
wherein an operating time period of the NFV-based multi-domain network is equally divided into several time slots;
it is assumed that new SFC request information is collected in a time slot t−1, an SFC is deployed in a time slot t, and meanwhile, migration of resources of software Ψq is executed and completed in the time slot t;
one binary variable
Y
n
τ
⁢
i
f
rh
(
t
)
is defined to indicate whether the server node nτi supports the VNF ƒrh in the time slot t;
and
χ
ψ
q
n
τ
⁢
i
(
t
)
is a binary migration decision variable indicating whether the software Ψq is migrated for the server node nτi within the time slot t, wherein
Y
n
τ
⁢
i
f
rh
(
t
)
=
∏
ψ
q
∈
Ψ
rh
Z
n
τ
⁢
i
ψ
q
(
t
)
·
ResourceConstraint
,
(
3
)
Z
n
τ
⁢
i
ψ
q
(
t
)
is a binary variable indicating whether the software Ψq is on the server node nτi in the time slot t;
Ψrh is a dependent software set supporting operation of the virtual network function ƒrh;
and ResourceConstraint is an indication variable indicating whether other resources on the server node nτi are sufficient to support operation of the VNF ƒrh, wherein when the resources on the server node nτi are sufficient, a value of the indication variable is 1, and a corresponding mathematical expression is:
χ
ψ
q
n
τ
⁢
i
(
t
)
=
[
1
-
Z
n
τ
⁢
i
ψ
q
(
t
-
1
)
]
·
[
Z
n
τ
⁢
i
ψ
q
(
t
-
1
)
⊕
Z
n
τ
⁢
i
ψ
q
(
t
)
]
,
(
4
)
wherein when
χ
ψ
q
n
τ
⁢
i
(
t
)
,
it indicates that the software Ψq has been migrated to the server node nτi in the time slot t, and otherwise, it indicates that the software Ψq has not been migrated;
Ψ
f
rh
mig
is used to represent a software resource set that needs to be migrated for the VNF ƒrh;
and after software that needs to be migrated is determined, software resources on a corresponding node are updated;
(3) formulating problems to be solved and determining an optimization objective based on the network topology and the service request model constructed in step (2), wherein
the problems to be solved are defined as follows:
an SFC deployment problem, wherein given a domain set of a network and an SFC request set Γ, a routing path of an SFC and a deployment policy thereof are determined, and quality of the selected path is considered to minimize an SFC placement cost and ensure an end-to-end latency of the SFC while a constraint of physical network resources is satisfied;
and
a VNF-dependent software migration problem, wherein based on the given domain set of the network and an SFC deployment result in combination with a distribution matrix Z of current software resources, a migration policy of software and a migration path thereof are determined;
and considering a VNF's demand for dependent software, when a selected server node is unable to provide sufficient software resources, a migration cost is minimized;
and
an overall optimization objective is determined based on multi-domain network information, user terminal service request information, and the VNF-dependent software migration model, wherein the overall optimization objective is to minimize the end-to-end latency of all SFCs and costs related to SFC deployment and VNF-dependent software, that is, a VNF-dependent software migration cost and a VNF-dependent software placement cost, wherein an end-to-end latency of the SFC request is defined as a sum of link latencies Dr, with a mathematical expression as follows:
D
r
=
∑
ξ
f
rg
,
f
rh
∈
E
r
∑
e
τ
⁢
i
,
τ
^
⁢
j
∈
E
y
ξ
f
rg
,
f
rh
e
τ
⁢
i
,
τ
^
⁢
j
·
l
e
τ
⁢
i
,
τ
^
⁢
j
+
∑
f
rh
∈
F
r
∑
n
τ
⁢
i
∈
N
x
rh
n
τ
⁢
i
·
l
n
τ
⁢
i
(
5
)
wherein leτi,{circumflex over (τ)}j is a latency on the link eτi,{circumflex over (τ)}j, and lnτi is a processing latency on the server node nτi;
a placement cost of the SFC request r is defined as
C
r
d
,
and a total placement cost of the SFC request r is represented by
C
r
s
,
wherein
C
r
d
consists of node resource usage costs, with the following expression:
C
r
d
=
∑
f
rh
∈
F
r
∑
n
τ
⁢
i
∈
N
x
f
rh
n
τ
⁢
i
·
(
c
n
τ
⁢
i
CPU
·
R
f
rh
c
+
c
n
τ
⁢
i
m
⁢
e
⁢
m
·
R
f
rh
m
)
(
6
)
and
C
r
s
consists of the VNF-dependent software migration cost and the VNF-dependent software placement cost, and is defined as follows:
C
r
s
=
∑
f
rh
∈
F
r
∑
ψ
q
∈
Ψ
f
rh
mig
∑
p
τ
⁢
i
,
τ
^
⁢
j
∈
L
ψ
q
y
p
τ
⁢
i
,
τ
^
⁢
j
e
τ
⁢
i
,
τ
^
⁢
j
·
l
e
τ
⁢
i
,
τ
^
⁢
j
+
∑
f
rh
∈
F
r
∑
ψ
q
∈
Ψ
f
rh
mig
x
f
rh
n
τ
⁢
i
·
χ
ψ
q
n
τ
⁢
i
·
c
n
τ
⁢
i
s
⁢
t
⁢
o
·
R
ψ
q
s
,
(
7
)
a service delivery cost Cr of the SFC request r is defined as follows:
C
r
=
C
r
d
+
C
r
s
,
(
8
)
and a joint optimization objective is expressed as follows:
min
⁢
∑
Γ
r
∈
Γ
ω
1
⁢
D
r
+
ω
2
⁢
C
r
(
9
)
wherein ω1 and ω2 are adjustable weight factors for balance each objective;
by adjusting a weight factor of each objective, a preference of a specific objective is highlighted, and constraint conditions of physical network resources and quality of service of the SFC are satisfied, wherein
constraint conditions (10) and (11) ensure that on any server node nτi, total central processing unit (CPU) and memory resource demands required for SFC deployment are restricted to respective maximum CPU and memory resource capacities:
∑
Γ
r
∈
Γ
∑
f
r
⁢
h
∈
F
r
x
f
r
⁢
h
n
τ
⁢
i
·
R
f
r
⁢
h
c
≤
ϕ
n
τ
⁢
i
c
,
∀
n
τ
⁢
i
∈
N
,
(
10
)
∑
Γ
r
∈
Γ
∑
f
r
⁢
h
∈
F
r
x
f
r
⁢
h
n
τ
⁢
i
·
R
f
r
⁢
h
m
≤
ϕ
n
τ
⁢
i
m
,
∀
n
τ
⁢
i
∈
N
(
11
)
a constraint condition (12) ensures that used storage resources shall not exceed a maximum storage resource capacity:
∑
ψ
q
∈
Ψ
n
τ
⁢
i
Z
n
τ
⁢
i
ψ
q
·
R
ψ
q
S
≤
ϕ
n
τ
⁢
i
s
,
∀
n
τ
⁢
i
,
∈
N
,
(
12
)
wherein Ψnτi is a software set on the server node nτi;
and similarly, total bandwidth consumption on any link eτi,{circumflex over (τ)}j must be less than a maximum bandwidth capacity, with the following constraint condition:
∑
Γ
r
∈
Γ
∑
ξ
f
rg
,
f
rh
∈
E
r
y
ξ
f
rg
,
f
rh
e
τ
⁢
i
,
τ
^
⁢
j
·
b
r
≤
b
e
τ
⁢
i
,
τ
^
⁢
j
,
∀
e
τ
⁢
i
,
τ
^
⁢
j
∈
E
.
(
13
)
to satisfy the quality of service, a latency constraint (14) ensures that the end-to-end latency of any SFC request r must be satisfied, with the following constraint condition:
D
r
≤
l
r
¯
,
∀
Γ
r
∈
Γ
(
14
)
and a constraint (15) ensures that each VNF ƒrh can be successfully deployed on only one server node at most, which means that a VNF instance is inseparable, and corresponds to:
∑
n
τ
⁢
i
,
∈
N
x
f
r
⁢
h
n
τ
⁢
i
≤
1
,
∀
Γ
r
∈
Γ
,
∀
f
r
⁢
h
∈
F
r
(
15
)
wherein to simplify SFC deployment, it is assumed that an ingress node of the SFC request r has only one outgoing link, and an egress node has only one incoming link, so as to process a user request;
and at any intermediate node on a path selected for the SFC request r, the SFC request r is represented as SFC r in mathematical notation, wherein the SFC r uses only one incoming link and one outgoing link;
and if and only if the SFC r uses the link eτi,{circumflex over (τ)}j, a variable
y
r
e
τ
⁢
i
,
τ
^
⁢
j
is equal to 1:
∑
n
e
τ
⁢
i
,
τ
^
⁢
j
,
1
=
s
r
y
r
e
τ
⁢
i
,
τ
^
⁢
j
=
1
,
∀
Γ
r
∈
Γ
,
(
16
)
∑
n
e
τ
⁢
i
,
τ
^
⁢
j
,
2
=
t
r
y
r
e
τ
⁢
i
,
τ
^
⁢
j
=
1
,
∀
Γ
r
∈
Γ
,
(
17
)
∑
n
e
τ
⁢
i
,
τ
^
⁢
j
,
1
=
n
y
r
e
τ
⁢
i
,
τ
^
⁢
j
-
∑
n
e
τ
⁢
i
,
τ
^
⁢
j
,
2
=
n
y
r
e
τ
⁢
i
,
τ
^
⁢
j
=
0
,
∀
Γ
r
∈
Γ
,
∀
n
∈
N
≠
s
r
,
t
r
;
(
18
)
and (4) designing a layered architecture and a deployment and migration mechanism, wherein a multi-layer network architecture is adopted, each VNF corresponds to an independent layer of network, a matching relationship between each VNF and all nodes is calculated based on an analytic hierarchy process, and a multi-layer network weighted graph is constructed, wherein a shortest path for deploying an SFC and a placement node of the VNF are determined from the multi-layer weighted graph based on a dynamic programming algorithm, and a migration policy of the VNF-dependent software is determined after the placement node of the VNF is obtained.

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Method for deploying sfc in multi-domain network based on vnf dependency component migration

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Method for deploying sfc in multi-domain network based on vnf dependency component migration

Life of this patent

Abstract

Claims4