CN111385202B - Route distribution method based on virtual network function - Google Patents

Route distribution method based on virtual network function Download PDF

Info

Publication number
CN111385202B
CN111385202B CN202010185421.1A CN202010185421A CN111385202B CN 111385202 B CN111385202 B CN 111385202B CN 202010185421 A CN202010185421 A CN 202010185421A CN 111385202 B CN111385202 B CN 111385202B
Authority
CN
China
Prior art keywords
sfc
node
request
vnf
service function
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202010185421.1A
Other languages
Chinese (zh)
Other versions
CN111385202A (en
Inventor
黄梅根
汪涛
庞瑞琴
刘亮
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Chongqing University of Post and Telecommunications
Original Assignee
Chongqing University of Post and Telecommunications
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Chongqing University of Post and Telecommunications filed Critical Chongqing University of Post and Telecommunications
Priority to CN202010185421.1A priority Critical patent/CN111385202B/en
Publication of CN111385202A publication Critical patent/CN111385202A/en
Application granted granted Critical
Publication of CN111385202B publication Critical patent/CN111385202B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/12—Shortest path evaluation
    • H04L45/124—Shortest path evaluation using a combination of metrics
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/12—Shortest path evaluation
    • H04L45/125—Shortest path evaluation based on throughput or bandwidth
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00—Traffic control in data switching networks
    • H04L47/10—Flow control; Congestion control
    • H04L47/12—Avoiding congestion; Recovering from congestion
    • H04L47/125—Avoiding congestion; Recovering from congestion by balancing the load, e.g. traffic engineering

Abstract

The invention relates to the technical field of computer networks, in particular to a routing distribution method based on virtual network functions, which comprises the steps of establishing a physical network model and defining service function chain SFC request flow; modeling according to the defined service function chain SFC to obtain a service function chain SFC model; acquiring the resource cost consumed by the service function chain SFC request flow in the physical network according to the service function chain SFC model; constructing a multi-stage directed graph, and mapping the resource cost consumed by the service function chain SFC request flow in the physical network to the multi-stage directed graph to obtain the relative cost of the service function chain SFC request flow; calculating a routing path with the lowest relative cost for acquiring the service function chain SFC request flow, and taking the path as a routing path distributed by the current routing; the invention realizes the virtual network function deployment and route distribution considering the global network resources, effectively realizes the load balance of the network resources and improves the request acceptance rate.

Description

Route distribution method based on virtual network function
Technical Field
The invention relates to the technical field of computer networks, in particular to a routing distribution method based on a virtual network function.
Background
In the existing Virtual Network Function (VNF) deployment policy research, most of the research only considers the constraint of one Network resource in the global Network to implement the VNF deployment, and does not comprehensively consider the constraint of the global Network resource. If a VNF deployment method based on a tabu search algorithm is provided for research, the method searches a deployment position with an optimal service function in a global network in a mode of setting a tabu table, but only considers the node resource utilization rate; some researches provide a service Function management mechanism facing the Network Function Virtualization (NFV) technical environment, and the mechanism mainly selects a node with the minimum deployment cost from candidate nodes as a Function node through a viterbi algorithm, so that the deployment cost of a service Function is effectively reduced, but the service Function management mechanism lacks consideration on link resource cost; some researches provide a service function deployment model, which adopts an Auxiliary Frequency Slot Matrix heuristic algorithm to solve, but an AFM (automatic Frequency Slot Matrix, AFM) only takes the calculation resource capacity of a physical node as a selection strategy, and does not consider the deployment problem of VNF from the utilization of global service path resources; some researches exhaust all service paths meeting resource constraint and connectivity through a Greedy algorithm, and select the service path with the minimum link resource occupation, but the method only focuses on the optimization selection problem of the link; some researches propose a service function deployment mechanism under an NFV architecture, the mechanism constructs a layered graph model, minimizes time delay as a basis for selecting a service path, and although the processing time of a service function chain is reduced, the mechanism lacks consideration of node resources.
The deployment strategies are researched from respective angles, but the considered resource optimization targets are single, and global network resources, such as only link bandwidth resources or only node resources, are not fully considered.
Disclosure of Invention
In order to effectively deploy virtual network functions and seek an optimal routing path for a service function chain request, and finally achieve load balancing of global network resources and improve the acceptance rate of the request, the invention provides a routing allocation method based on the virtual network functions, which comprises the following steps:
establishing a physical network model, and defining a Service Function Chain (SFC) request flow;
modeling according to the defined service function chain SFC to obtain a service function chain SFC model;
acquiring the resource cost consumed by the service function chain SFC request flow in the physical network according to the service function chain SFC model;
constructing a multi-stage directed graph, and mapping the resource cost consumed by the service function chain SFC request flow in the physical network to the multi-stage directed graph to obtain the relative cost of the service function chain SFC request flow;
and calculating a routing path with the lowest relative cost for acquiring the service function chain SFC request flow based on an integer linear programming model, and taking the path as a routing path allocated by the current routing.
Further, establishing the physical network model includes:
defining a physical network as an undirected graph G ═ V, L, where V and L represent a set of physical nodes and a set of physical links, respectively;
the nodes in the physical network are connected with one another to form a physical link;
defining N as a server set, wherein N is one server in the server set;
if the VNF is deployed on a physical node attached with a server and the physical node bears the VNF function, defining a set of the physical nodes with the VNF function as a function node set and defining other points as a switch node set;
defining a set M to represent a set of VNF functions in all virtual networks, wherein M belongs to M and represents one virtual network function in the set of VNF;
and P represents the collection of the flow with the SFC request, and the construction of the physical network model is completed.
Further, defining the service function chain SFC request flows includes defining each SFC request flow to be composed of an ingress node, an egress node, and a service function chain composed of VNFs, and representing the SFC request flows and the service function chain as:
pi＝(si，ti；SCi，bwi，CPi)；
Figure BDA0002414011810000031
wherein p isiRepresenting a stream of SFC requests; siIngress node representing a request flow；tiAn egress node representing an SFC request flow; SC (Single chip computer)iOrdered VNF sequences, SC, representing the SFC request flow that must pass sequentiallyi,lThe i-th VNF request through which the SFC request flows is represented,<SCi,1,SCi,2,…,SCi,l>an ordered VNF sequence representing the sequential order in which SFC request streams must pass; lSCiRepresents the service function chain length, | SC, of the SFC request flowiI denotes SCiThe VNF request total of (a); bwiRepresenting SFC request stream piThe requested bandwidth resource of (2); CP (CP)iRepresenting SFC request stream piThe computing resources of (1).
Further, the service function chain SFC model is represented as:
Figure BDA0002414011810000032
wherein the content of the first and second substances,
Figure BDA0002414011810000033
resource cost consumed by a service function chain SFC request flow;
Figure BDA0002414011810000034
representing the total cost of link bandwidth consumed by the SFC request stream routing path;
Figure BDA0002414011810000035
the total cost of switch flow table entry resources consumed by the flow routing path for the SFC request;
Figure BDA0002414011810000036
the computing resources of the functional nodes consumed for the SFC request flow routing path consume the total cost.
Further, the total cost of the link bandwidth consumed by the SFC request stream routing path is calculated
Figure BDA0002414011810000037
The bandwidth resource consumption requested by the SFC cannot exceed the bandwidth resource remaining on the physical link,
Figure BDA0002414011810000038
expressed as:
Figure BDA0002414011810000039
wherein the content of the first and second substances,
Figure BDA00024140118100000310
representing service function chain links
Figure BDA00024140118100000311
Whether or not to map onto a link uv in a physical network, when the service function chain link
Figure BDA00024140118100000312
When mapped onto a link uv in a physical network
Figure BDA00024140118100000313
Otherwise
Figure BDA00024140118100000314
L denotes the set of all links in the physical network,
Figure BDA00024140118100000315
represents the set of all service function chain links;
Figure BDA00024140118100000316
representing the bandwidth resource cost of the physical link uv.
Further, the total cost of the switch flow table entry resources consumed by the SFC request flow routing path is calculated
Figure BDA00024140118100000317
The flow table entry resources consumed by the SFC request cannot exceed the flow table entry resources remaining on the switch node,
Figure BDA0002414011810000041
expressed as:
Figure BDA0002414011810000042
wherein, VsRepresenting a set of switch nodes;
Figure BDA0002414011810000043
representing a flow table resource cost of the switch node u;
Figure BDA0002414011810000044
to represent a link
Figure BDA0002414011810000045
Whether to traverse the binary variable of the physical node u, and if so, whether to traverse the binary variable of the physical node u
Figure BDA0002414011810000046
Otherwise
Figure BDA0002414011810000047
Further, computing the total cost of computing the computing resources of the functional nodes that the SFC request flow consumes by the routing path
Figure BDA0002414011810000048
At that time, all CPUs on the functional node requested by the SFC consume no more CPU than the remainder of the CPUs on the selected functional node,
Figure BDA0002414011810000049
expressed as:
Figure BDA00024140118100000410
wherein, VmRepresents a collection of all the functional nodes that are,
Figure BDA00024140118100000411
a VNF request in one service function chain representing a request flow i,
Figure BDA00024140118100000412
representing a set of all VNF nodes in a service function chain of a request flow i, N representing one server, N being a set of all servers, M representing one of all VNF nodes, M representing a set of all VNF nodes;
Figure BDA00024140118100000413
the computational resource cost of functional node u; h isn,vA binary variable representing whether server n is attached to physical node v, if so, h n,v1, otherwise hn,v＝0；
Figure BDA00024140118100000414
Presentation request
Figure BDA00024140118100000415
Binary variable of whether or not to be served by VNF node m, if being served
Figure BDA00024140118100000416
Otherwise
Figure BDA00024140118100000417
yn,mA binary variable representing whether or not the VNF node m is deployed on the server n, and when deployed y n,m1, otherwise yn,m＝0。
Further, constructing a multi-stage directed graph and mapping resource costs consumed by service function chain SFC request flows in a physical network to the multi-stage directed graph comprises:
constructing a network graph from an original network graph
Figure BDA00024140118100000418
A multi-stage directed graph of stages, wherein the first stage of the directed graph is an entry node, and the last stage of the directed graph is an exit node;
the jth stage of the directed graph is the j-1 VNF request of the SFC request flow deployed on the jth stage functional node,
Figure BDA00024140118100000419
for two adjacent stages, connecting each node in the ith stage to all points in the (i + 1) th stage in the direction from the ith stage to the (i + 1) th stage;
in a multi-stage directed graph, when a VNF request of one SFC request flow is served by a VNF on one functional node, that link will correspond to one functional node on the original network graph.
Further, the relative composition of the service function chain SFC request flow is represented as:
Figure BDA0002414011810000051
wherein the content of the first and second substances,
Figure BDA0002414011810000052
indicating a link
Figure BDA0002414011810000053
The relative cost of (c);
Figure BDA0002414011810000054
representing the resource cost of request i through link uv in the physical network,
Figure BDA0002414011810000055
representing service function chain links
Figure BDA0002414011810000056
Whether or not to map onto a link uv in a physical network, when the service function chain link
Figure BDA0002414011810000057
When mapped onto a link uv in a physical network
Figure BDA0002414011810000058
Otherwise
Figure BDA0002414011810000059
Figure BDA00024140118100000510
Representing the relative flow table resource cost of a switch node requesting i to traverse a link uv in the physical network;
Figure BDA00024140118100000511
representing functional nodes
Figure BDA00024140118100000512
Relative computing resource cost of;
Figure BDA00024140118100000513
representing multi-stage directed graph inner function nodes
Figure BDA00024140118100000514
The cost of computing resources of (a);
Figure BDA00024140118100000515
representing a set of all service function chain links in the multi-stage directed graph;
Figure BDA00024140118100000516
represents the set of all VNF nodes in the service function chain requesting flow i in the multi-stage directed graph.
Further, calculating a routing path with the lowest relative cost for acquiring the service function chain SFC request flow based on the integer linear programming model comprises:
s1: initializing a VNF queue Q, a mappable node set A, and a VNF deployment optimal location set
Figure BDA00024140118100000517
S2: set of all VNF nodes in the service function chain that will request flow i
Figure BDA00024140118100000518
Computing resources of VNFSource demand dmSequencing the data according to the sequence from small to large, and sequentially entering a queue Q;
s3: searching a set of functional nodes in a multi-stage directed graph
Figure BDA00024140118100000519
If all CPUs on the functional node requested by the SFC consume no more than the remaining CPUs on the selected functional node, adding the functional node to the set A;
s4: fetch the elements in queue Q and according to
Figure BDA0002414011810000061
Searching the functional nodes in the mappable set A, and deploying the VNF to the functional nodes
Figure BDA0002414011810000062
In the above, if the VNF is successfully deployed to the function node
Figure BDA0002414011810000063
In the above, the node is then connected
Figure BDA0002414011810000064
Adding to collections
Figure BDA0002414011810000065
Performing the following steps; otherwise, get
Figure BDA0002414011810000066
Updating the queue Q and updating the residual computing resource quantity of the corresponding functional node;
s5: if VNFs in the queue Q are not completely deployed, returning to the step S4; otherwise, all VNF deployments are completed, and the final VNF deployment is obtained
Figure BDA0002414011810000067
Gathering, finding an optimal routing path for the SFC request;
s6: searching all shortest paths in the multi-stage directed graph according to steps S1-S5;
s7: converting the shortest path obtained in the multi-stage directed graph into a physical network;
s8: judging whether the shortest path in the physical network is satisfied or not, and whether two end points of the selected path are also selected or not;
and whether the routing path of the SFC request flow is continuous;
and whether the bandwidth resource consumption requested by the SFC cannot exceed the bandwidth resource remaining on the physical link;
and the flow table entry resource consumption requested by the SFC cannot exceed the flow table entry resource remained on the switch node;
and all CPU consumption on the functional node requested by the SFC cannot exceed the residual CPU on the selected functional node;
if all the requirements are met, receiving request SFC request flow, updating residual bandwidth resources, calculating resources and flow table resources, and feeding back the routing path meeting the requirements; otherwise, the feedback route fails, and the request is rejected.
The invention realizes the scheme of optimizing the virtual network function deployment and route distribution considering the global network resources, effectively realizes the load balance of the network resources and improves the request acceptance rate.
Drawings
FIG. 1 is a schematic diagram of a service function chain;
FIG. 2 is a diagram of an original network;
FIG. 3 is a multi-stage directed graph illustration of the present invention;
fig. 4 is a schematic flow chart of a routing allocation method based on a virtual network function according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides a route distribution method based on virtual network function, as shown in fig. 4, which specifically comprises the following steps:
establishing a physical network model, and defining a Service Function Chain (SFC) request flow;
modeling according to the defined service function chain SFC to obtain a service function chain SFC model;
acquiring the resource cost consumed by the service function chain SFC request flow in the physical network according to the service function chain SFC model;
constructing a multi-stage directed graph, and mapping the resource cost consumed by the service function chain SFC request flow in the physical network to the multi-stage directed graph to obtain the relative cost of the service function chain SFC request flow;
and calculating the routing path with the lowest relative cost for acquiring the service function chain SFC request flow, and taking the path as the routing path allocated by the current route.
In this embodiment, a physical network is defined as an undirected graph G ═ V, L, where V and L represent a set of physical nodes and a set of physical links, respectively; u and V are physical nodes in a physical network, and belong to V; a physical link formed by connecting the node u and the node v is expressed as uv, and uv belongs to L; if the set of all servers is N, N belongs to N, and N represents one server in the set of servers; if the VNF is deployed on a physical node to which a server is attached and the physical node carries a VNF function, a set of all such physical nodes is defined as a set of function nodes VmDefining other physical nodes as a switch node set VsIn which V ism、VsAll belong to a physical node set V; setting one virtual network function in the VNF set as M, and setting the set of all the virtual network functions as M; an SDN controller is in the physical network G, and the controller monitors computing resources, link bandwidth resources, and switch flow table entry resources of the functional nodes in the physical network G, and performs resource allocation to meet resource requirements of each request flow.
If the set of streams with SFC requests is P, one request stream in the set is denoted as PiFlow table traffic of switch node u is
Figure BDA0002414011810000081
When the SFC requests a stream PiThe ratio of the remaining flow table resources of switch node u upon arrival is
Figure BDA0002414011810000082
The total amount of computing resources on the functional node is
Figure BDA0002414011810000083
The total bandwidth resource of the physical link uv is
Figure BDA0002414011810000084
When the SFC requests a stream PiWhen arriving, the ratio of the residual computing resources on the functional node and the ratio of the residual bandwidth resources on the link uv are respectively
Figure BDA0002414011810000085
And
Figure BDA0002414011810000086
in a network, a user-initiated flow should always traverse a set of VNFs connected in a predefined order to meet the user's needs. Assuming that all flows have SFC requests, each flow consisting of an ingress node, an egress node, and a service function chain consisting of VNFs, the flow of SFC requests may be represented by a five-tuple, and the flow of SFC requests and the service function chain may be represented as:
pi＝(si,ti；SCi,bwi,CPi) (1)
Figure BDA0002414011810000087
wherein s isiEntry node, t, representing a request flowiAn egress node representing an SFC request flow; each SFC request stream is from source siTo the target tiMust pass through the corresponding functional nodes in sequence; request streamIs defined as SCi，SCi,lThe i-th VNF request through which the SFC request flows is represented,<SCi,1，SCi,2，…，SCi，l>an ordered VNF sequence that represents the SFC request flow must pass sequentially, e.g. (Firewall → IDS → Proxy); represents the service function chain length, | SC, of the SFC request flowiI denotes SCiThe VNF request total of (a); for SFC request stream piIt requests bandwidth resources and computing resources bw respectivelyi、CPi。
Sequencing the VNF SC according to the service function chainiService function chain graph converted into directed acyclic
Figure BDA0002414011810000088
Wherein the content of the first and second substances,
Figure BDA0002414011810000089
representing a set of flow nodes (VNFS, ingress and egress switches),
Figure BDA00024140118100000810
representing the set of links between these flow nodes. A simple SFC request service function chain as shown in FIG. 1, requests flow with SCi,1→SCi,2→SCi,3In order through the flow nodes of the chain, the SFC requests the flow to reach the node tiBefore, it must first traverse the nodes s in sequencei，SCi,1、SCi,2And SCi,3. A traffic model constructed in this way can ensure that the request flow passes through the correct sequence of service function chains.
When an SFC request stream arrives, the resource consumption of the network consists of four main parts: 1. the functional nodes are provided with computing resources required by a certain VNF; 2. the VNF on the functional node provides corresponding service computing resource consumption for the SFC request flow; 3. physical link bandwidth resource consumption; 4. switch node flow table resource consumption.
There is an important characteristic for resource usage on physical nodes and links in G: the marginal cost of resource usage expands as the resource load increases,the more loaded nodes and links will cost more overhead than less loaded nodes and links. Therefore, when receiving a request flow, a less loaded node and link should be used, and when an SFC request flow arrives, the available flow table entry of the switch node is
Figure BDA0002414011810000091
The remaining bandwidth resource of the link uv is
Figure BDA0002414011810000092
Defining the amount of computing resources required to deploy a certain VNF on a functional node as dmRespectively characterizing the resource consumption cost of a flow table using the following function
Figure BDA0002414011810000093
Link bandwidth resource consumption cost
Figure BDA0002414011810000094
Computing resource consumption cost
Figure BDA0002414011810000095
Expressed as:
Figure BDA0002414011810000096
wherein, alpha is a minimum value to ensure that the denominator is greater than zero; flow table resource consumption cost
Figure BDA0002414011810000097
Link bandwidth resource consumption cost
Figure BDA0002414011810000098
Computing resource consumption cost
Figure BDA0002414011810000099
Is (1, infinity), and the corresponding resource marginal cost is non-linear with flow table entries, link bandwidth, and consumption of computational resourcesThe form grows and becomes larger and larger. Thus, the formula may adequately represent that the marginal cost of corresponding resource usage expands as the resource load increases.
The optimization model of the integer linear programming is to comprehensively consider the conditions of service resource requirements, network node resources, network link resources and the like, and find the optimal position of VNF deployment according to a specified objective function. The problem is characterized as an integer linear programming model with the aim of minimizing resource cost.
In integer linear programming, the following binary variables are defined:
binary variable h attached to physical node u on server nn，uExpressed as:
Figure BDA0002414011810000101
VNF requests
Figure BDA0002414011810000102
Binary variable of whether or not to be served by VNF node m
Figure BDA0002414011810000103
Expressed as:
Figure BDA0002414011810000104
binary variable y of whether VNF node m is deployed on server nn,mExpressed as:
Figure BDA0002414011810000105
the following two variables represent logical links, respectively
Figure BDA0002414011810000106
Whether via physical link uv or physical node u:
Figure BDA0002414011810000107
Figure BDA0002414011810000108
once a link is selected, the two endpoints of the link must also be selected, denoted as:
Figure BDA0002414011810000109
connectivity constraints, ensuring that the routing path of the SFC request stream is continuous:
Figure BDA00024140118100001010
for physical link uv, the bandwidth resource consumption requested by the SFC cannot exceed the bandwidth resource remaining on the physical link:
Figure BDA00024140118100001011
the flow table entry resource consumption of the SFC request cannot exceed the flow table entry resources remaining on the switch node, and the following constraints must be satisfied:
Figure BDA0002414011810000111
furthermore, all CPUs on the functional node requested by the SFC consume no more CPU than the remaining CPUs on the selected functional node, expressed as:
Figure BDA0002414011810000112
SFC requests total cost of link bandwidth consumed by the flow routing path:
Figure BDA0002414011810000113
SFC requests total cost of switch flow table entry resources consumed by flow routing path:
Figure BDA0002414011810000114
the SFC requests that the computing resources of the functional nodes consumed by the flow routing path consume the total cost:
Figure BDA0002414011810000115
total cost of resource consumption on the route path of the SFC request flow:
Figure BDA0002414011810000116
if the resource consumption cost of a certain path is low, it can be determined that the remaining resources on the path are rich, and the routing flow with the SFC request on the path does not cause network congestion. On the contrary, if the resource consumption cost of a certain path is very high, it can be determined that a bottleneck link or node exists on the path, and another path with lower resource consumption cost needs to be found to avoid network congestion and achieve load balancing.
After the above calculation of the total cost is completed, constructing a multi-stage directed graph and mapping the resource cost consumed by the service function chain SFC request flow in the physical network to the multi-stage directed graph, wherein the multi-stage directed graph comprises the following steps:
constructing a network graph from an original network graph
Figure BDA0002414011810000117
A multi-stage directed graph of stages, wherein the first stage of the directed graph is an entry node, and the last stage of the directed graph is an exit node;
the jth stage of the directed graph is the j-1 VNF request of the SFC request flow deployed on the jth stage functional node,
Figure BDA0002414011810000118
for two adjacent stages, connecting each node in the ith stage to all points in the (i + 1) th stage in the direction from the ith stage to the (i + 1) th stage;
in a multi-stage directed graph, when a VNF request of one SFC request flow is served by a VNF on one functional node, that link will correspond to one functional node on the original network graph.
As in fig. 3, will be established
Figure BDA0002414011810000121
The multi-stage directed graph of the stages is represented as
Figure BDA0002414011810000122
And
Figure BDA0002414011810000123
respectively show diagrams
Figure BDA0002414011810000124
Node and a link. The first stage and the last stage respectively have only one entrance node
Figure BDA0002414011810000125
And an egress node
Figure BDA0002414011810000126
Phase j represents the j-1 st VNF request of the SFC request stream deployed on the j-th phase function node,
Figure BDA0002414011810000127
after the node arrangement of all the stages is completed, each node in the previous column is connected to all the nodes in the next column for every two adjacent columns. The direction of the link is from the node of the previous column to the nextThe nodes of the column.
In the figure
Figure BDA0002414011810000128
In the other stages, except that only one node is provided in the first stage and the last stage, functional nodes in the original network diagram are respectively placed in each stage, and the functional nodes can deploy certain VNFs. For two VNFs deployed on different functional nodes, a flow with an SFC request needs to traverse a complete path through both VNFs. Thus, the figures
Figure BDA0002414011810000129
VNF links connecting different functional nodes in the network correspond to respective paths on the original network graph. However, since one functional node may deploy multiple different VNFs, for the graph
Figure BDA00024140118100001210
When a VNF request of an SFC request flow is served by a VNF on a functional node, the link will correspond to a functional node on the original network graph.
From the original network mesh G and the multi-stage directed graph
Figure BDA00024140118100001211
The sum of three relative resource costs, namely bandwidth resources, flow table resources and calculation resources in the original network graph can be used as the weight of the link in the multistage directed graph. For the figure
Figure BDA00024140118100001212
In (1),
Figure BDA00024140118100001213
is defined as a link cost of
Figure BDA00024140118100001214
Binary variable
Figure BDA00024140118100001215
Indicating whether or not to link
Figure BDA00024140118100001216
Traversing physical link uv ∈ L, binary variable
Figure BDA00024140118100001217
Indicating whether or not to link
Figure BDA00024140118100001218
And traversing the physical node u epsilon V. In addition, a mapping function is defined
Figure BDA00024140118100001219
To obtain a functional node deploying a VNF and
Figure BDA00024140118100001220
representing functional nodes
Figure BDA00024140118100001221
Relative cost of computing resources. The following formula
Figure BDA00024140118100001222
Relative cost of the link
Figure BDA00024140118100001223
Figure BDA0002414011810000131
In the figure
Figure BDA0002414011810000132
The path minimum resource cost is calculated according to equation (21). Wherein, binary variables
Figure BDA0002414011810000133
Is shown in the figure
Figure BDA0002414011810000134
In (1)
Figure BDA0002414011810000135
Whether to traverse the graph
Figure BDA0002414011810000136
In (1)
Figure BDA0002414011810000137
Figure BDA0002414011810000138
Finally, a routing path with the lowest relative cost for acquiring the service function chain SFC request flow is calculated based on an integer linear programming model, and the related algorithm for taking the path as the routing path allocated by the current routing comprises the following steps:
inputting: SFC request stream pi＝(si,ti；SCi,bwi,CPi) Physical network G ═ V, L, service function chain graph
Figure BDA0002414011810000139
Resource capacity:
Figure BDA00024140118100001310
resource surplus rate:
Figure BDA00024140118100001311
and (3) outputting:
Figure BDA00024140118100001312
1. building a multi-stage directed graph from an original physical network graph
Figure BDA00024140118100001313
2. A VNF queue Q is initialized.
3. A set of mappable nodes a is initialized.
4. Initializing a VNF deployment optimal location set
Figure BDA00024140118100001314
5. Computing resource demand d of VNF in set VmAnd the data are sorted from small to large and sequentially enter a queue Q.
6. A set of mappable nodes a is constructed. Search function node set
Figure BDA00024140118100001315
If the remaining amount of computing resources of the functional node
Figure BDA00024140118100001316
The constraint is satisfied (15), then this functional node is added to the set a.
7. Selecting a VNF optimal deployment location
Figure BDA00024140118100001317
Fetch the elements in queue Q and according to
Figure BDA00024140118100001318
Searching the functional nodes in the mappable set A, and deploying the VNF to the functional nodes
Figure BDA00024140118100001319
In the above, if the VNF is successfully deployed to the function node
Figure BDA00024140118100001320
In the above, the node is then connected
Figure BDA00024140118100001321
Adding to collections
Figure BDA0002414011810000141
Performing the following steps; otherwise, according to
Figure BDA0002414011810000142
And obtaining the suboptimal solution, updating the queue Q, and updating the residual computing resource quantity of the corresponding functional node.
8. If VNFs in the queue Q are not completely deployed, returning to the step 7; otherwise, all VNF deployments are completed, and the final VNF deployment is obtained
Figure BDA0002414011810000143
And (4) collecting.
9. An optimal routing path is found for the SFC request.
10. The initialization k is 1.
11.While k≤K do
In the figure
Figure BDA0002414011810000144
In accordance with the formula (21) to calculate the k-ththOne shortest path to obtain
Figure BDA0002414011810000145
Will be in the figure
Figure BDA0002414011810000146
The shortest path obtained in (1) is converted into a graph G to obtain routG；
Figure BDA0002414011810000147
Returning a routing failure and rejecting the request.
In the pseudo code, K represents the total number of shortest paths searched, routGRepresenting the routing path in the original network G.
It should be noted that u in this embodiment represents a node in a physical network, i.e., a node in fig. 1;
Figure BDA0002414011810000148
represents a node in a service function chain, i.e., a node in the original network shown in fig. 2;
Figure BDA0002414011810000149
are nodes in a multi-stage directed graph, i.e., nodes in the network shown in fig. 3.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (9)

1. A route distribution method based on virtual network function is characterized by comprising the following steps:
establishing a physical network model, and defining a Service Function Chain (SFC) request flow;
modeling is carried out according to the defined service function chain SFC, and a service function chain SFC model is obtained and is expressed as follows:
Figure FDA0003482055340000011
wherein the content of the first and second substances,
Figure FDA0003482055340000012
resource cost consumed by a service function chain SFC request flow;
Figure FDA0003482055340000013
representing the total cost of link bandwidth consumed by the SFC request stream routing path;
Figure FDA0003482055340000014
the total cost of switch flow table entry resources consumed by the flow routing path for the SFC request;
Figure FDA0003482055340000015
the total cost of computing resource consumption of the functional nodes consumed for the SFC request stream routing path;
acquiring the resource cost consumed by the service function chain SFC request flow in the physical network according to the service function chain SFC model;
constructing a multi-stage directed graph, and mapping the resource cost consumed by the service function chain SFC request flow in the physical network to the multi-stage directed graph to obtain the relative cost of the service function chain SFC request flow;
and calculating a routing path with the lowest relative cost for acquiring the service function chain SFC request flow based on an integer linear programming model, and taking the path as a routing path allocated by the current routing.
2. The routing distribution method based on virtual network function of claim 1, wherein establishing a physical network model comprises:
defining a physical network as an undirected graph G ═ V, L, where V and L represent a set of physical nodes and a set of physical links, respectively;
the nodes in the physical network are connected with one another to form a physical link;
defining N as a server set, wherein N is one server in the server set;
if the VNF is deployed on a physical node attached with a server and the physical node bears the VNF function, defining a set of the physical nodes with the VNF function as a function node set and defining other points as a switch node set;
defining a set M to represent a set of VNF functions in all virtual networks, wherein M belongs to M and represents one virtual network function in the set of VNF;
and P represents the collection of the flow with the SFC request, and the construction of the physical network model is completed.
3. The virtual network function-based routing assignment method of claim 2, wherein defining service function chain SFC request flows comprises defining each SFC request flow to be composed of an ingress node, an egress node, and a service function chain composed of VNFs, and representing the SFC request flows and the service function chain as:
pi＝(si,ti；SCi,bwi,CPi)；
SCi＝<SCi,1,SCi,2,…,SCi,l>，
Figure FDA0003482055340000021
wherein p isiRepresenting a stream of SFC requests; siAn ingress node representing a request flow; t is tiAn egress node representing an SFC request flow; SC (Single chip computer)iOrdered VNF sequences, SC, representing the SFC request flow that must pass sequentiallyi,lThe i-th VNF request through which the SFC request flows is represented,<SCi,1,SCi,2,…,SCi,l>an ordered VNF sequence representing the sequential order in which SFC request streams must pass;
Figure FDA0003482055340000022
represents the service function chain length, | SC, of the SFC request flowiI denotes SCiThe VNF request total of (a); bwiRepresenting SFC request stream piThe requested bandwidth resource of (2); CP (CP)iRepresenting SFC request stream piThe computing resources of (1).
4. The virtual network function-based routing allocation method of claim 1, wherein the total cost of the link bandwidth consumed by the SFC request stream routing path is calculated
Figure FDA0003482055340000023
The bandwidth resource consumption requested by the SFC cannot exceed the bandwidth resource remaining on the physical link,
Figure FDA0003482055340000024
expressed as:
Figure FDA0003482055340000025
wherein the content of the first and second substances,
Figure FDA0003482055340000026
representing service function chain links
Figure FDA0003482055340000027
Whether or not to map onto a link uv in a physical network, when the service function chain link
Figure FDA0003482055340000028
When mapped onto a link uv in a physical network
Figure FDA0003482055340000029
Otherwise
Figure FDA00034820553400000210
L denotes the set of all links in the physical network,
Figure FDA00034820553400000211
represents the set of all service function chain links;
Figure FDA00034820553400000212
representing the bandwidth resource cost of the physical link uv.
5. The routing allocation method based on virtual network function of claim 1, wherein the total cost of switch flow table entry resources consumed by SFC request flow routing path is calculated
Figure FDA00034820553400000213
The flow table entry resources consumed by the SFC request cannot exceed the flow table entry resources remaining on the switch node,
Figure FDA0003482055340000031
expressed as:
Figure FDA0003482055340000032
wherein, VsRepresenting a set of switch nodes;
Figure FDA0003482055340000033
a chain of service function links is represented,
Figure FDA0003482055340000034
represents the set of all service function chain links;
Figure FDA0003482055340000035
representing a flow table resource cost of the switch node u;
Figure FDA0003482055340000036
to represent a link
Figure FDA0003482055340000037
Whether to traverse the binary variable of the physical node u, and if so, whether to traverse the binary variable of the physical node u
Figure FDA0003482055340000038
Otherwise
Figure FDA0003482055340000039
6. The method of claim 1, wherein computing the total cost of computing resources of the functional nodes consumed by the SFC request flow routing path
Figure FDA00034820553400000310
At that time, all CPUs on the functional node requested by the SFC consume no more CPU than the remainder of the CPUs on the selected functional node,
Figure FDA00034820553400000311
expressed as:
Figure FDA00034820553400000312
wherein, VmRepresents a collection of all the functional nodes that are,
Figure FDA00034820553400000313
a VNF request in one service function chain representing a request flow i,
Figure FDA00034820553400000314
representing a set of all VNF nodes in a service function chain of a request flow i, N representing one server, N being a set of all servers, M representing one of all VNF nodes, M representing a set of all VNF nodes;
Figure FDA00034820553400000315
the computational resource cost of functional node u; h isn,vA binary variable representing whether server n is attached to physical node v, if so, hn,v1, otherwise hn,v＝0；
Figure FDA00034820553400000316
Presentation request
Figure FDA00034820553400000317
Binary variable of whether or not to be served by VNF node m, if being served
Figure FDA00034820553400000318
Otherwise
Figure FDA00034820553400000319
yn,mA binary variable representing whether or not the VNF node m is deployed on the server n, and when deployed yn,m1, otherwise yn,m＝0。
7. The virtual network function-based routing allocation method of claim 1, wherein constructing the multi-stage directed graph and mapping resource costs consumed by Service Function Chain (SFC) request flows in the physical network to the multi-stage directed graph comprises:
constructing a network graph from an original network graph
Figure FDA00034820553400000320
A multi-stage directed graph of stages, wherein the first stage of the directed graph is an entry node, and the last stage of the directed graph is an exit node;
the jth stage of the directed graph is the j-1 VNF request of the SFC request flow deployed on the jth stage functional node,
Figure FDA0003482055340000041
for two adjacent stages, connecting each node in the ith stage to all points in the (i + 1) th stage in the direction from the ith stage to the (i + 1) th stage;
in a multi-stage directed graph, when a VNF request of one SFC request flow is served by a VNF on one functional node, the link will correspond to one functional node on the original network graph;
wherein the content of the first and second substances,
Figure FDA0003482055340000042
|SCii denotes SCiVNF request total, SCiIndicating the ordered VNF sequence that the SFC request stream must sequentially pass through.
8. The virtual network function-based routing distribution method of claim 1, wherein the relative cost of the Service Function Chain (SFC) request flow is expressed as:
Figure FDA0003482055340000043
wherein the content of the first and second substances,
Figure FDA0003482055340000044
indicating a link
Figure FDA0003482055340000045
The relative cost of (c);
Figure FDA0003482055340000046
representing the resource cost of request i through link uv in the physical network,
Figure FDA0003482055340000047
representing service function chain links
Figure FDA0003482055340000048
Whether or not to map onto a link uv in a physical network, when the service function chain link
Figure FDA0003482055340000049
When mapped onto a link uv in a physical network
Figure FDA00034820553400000410
Otherwise
Figure FDA00034820553400000411
Figure FDA00034820553400000412
Representing the relative flow table resource cost of a switch node requesting i to traverse a link uv in the physical network;
Figure FDA00034820553400000413
represents the relative computational resource cost of the functional node u;
Figure FDA00034820553400000414
representing multi-stage directed graph inner function nodes
Figure FDA00034820553400000415
The cost of computing resources of (a); l represents the set of all service function chain links in the multi-stage directed graph; v represents the set of all VNF nodes in the service function chain requesting flow i in the multi-stage directed graph; l denotes a physical link set.
9. The routing distribution method based on virtual network functions of claim 1, wherein calculating the routing path with the lowest relative cost for acquiring the Service Function Chain (SFC) request flow based on the integer linear programming model comprises:
s1: initializing a VNF queue Q, a mappable node set A and a VNF deployment optimal position set Locopt(u)；
S2: set of all VNF nodes in the service function chain that will request flow i
Figure FDA0003482055340000051
Computing resource demand d of VNF inmSequencing the data according to the sequence from small to large, and sequentially entering a queue Q;
s3: searching a function node set V in the multi-stage directed graph, and if all CPUs on the function node requested by the SFC consume no more than the rest CPUs on the selected function node, adding the function node to the set A;
s4: fetch the elements in queue Q and according to
Figure FDA0003482055340000052
Searching the function nodes in the mappable set A, deploying the VNF to the function nodes u, and adding the nodes u to the set Loc if the VNF is successfully deployed to the function nodes uopt(u) in (u); otherwise, get
Figure FDA0003482055340000053
Updating the queue Q and updating the residual computing resource quantity of the corresponding functional node;
s5: if teamIf VNFs in column Q have not completed deployment, return to step S4; otherwise, all VNF deployments are completed, and the final Loc is obtainedopt(u) a set to find an optimal routing path for the SFC request;
s6: searching all shortest paths in the multi-stage directed graph according to steps S1-S5;
s7: converting the shortest path obtained in the multi-stage directed graph into a physical network;
s8: judging whether the shortest path in the physical network is satisfied or not, and whether two end points of the selected path are also selected or not;
and whether the routing path of the SFC request flow is continuous;
and whether the bandwidth resource consumption requested by the SFC cannot exceed the bandwidth resource remaining on the physical link;
and the flow table entry resource consumption requested by the SFC cannot exceed the flow table entry resource remained on the switch node;
and all CPU consumption on the functional node requested by the SFC cannot exceed the residual CPU on the selected functional node;
if all the requirements are met, receiving request SFC request flow, updating residual bandwidth resources, calculating resources and flow table resources, and feeding back the routing path meeting the requirements; otherwise, the feedback route fails, and the request is refused;
wherein the content of the first and second substances,
Figure FDA0003482055340000061
representing the remaining CPUs on functional node u, and epsilon (u) ═ u is the functional node where the VNF is deployed.
CN202010185421.1A 2020-03-17 2020-03-17 Route distribution method based on virtual network function Active CN111385202B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010185421.1A CN111385202B (en) 2020-03-17 2020-03-17 Route distribution method based on virtual network function

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010185421.1A CN111385202B (en) 2020-03-17 2020-03-17 Route distribution method based on virtual network function

Publications (2)

Publication Number Publication Date
CN111385202A CN111385202A (en) 2020-07-07
CN111385202B true CN111385202B (en) 2022-03-11

Family

ID=71221513

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010185421.1A Active CN111385202B (en) 2020-03-17 2020-03-17 Route distribution method based on virtual network function

Country Status (1)

Country Link
CN (1) CN111385202B (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113259440B (en) * 2021-05-18 2022-04-22 重庆邮电大学 Load balancing-based dynamic deployment method and system for virtual network functions
CN113411207B (en) * 2021-05-28 2022-09-20 中国人民解放军战略支援部队信息工程大学 Service function circulation arrangement basic platform and method of intelligent network service function chain
CN113507412B (en) * 2021-07-08 2022-04-19 中国人民解放军国防科技大学 SRv6 router progressive deployment method, system and storage medium in network interconnection
CN113556288B (en) * 2021-07-23 2022-10-28 中国科学技术大学苏州高等研究院 Service function link route updating device and method in multi-tenant cloud
CN114124796A (en) * 2021-10-26 2022-03-01 清华大学 Service chain deployment processing method and device, computer storage medium and terminal
CN114650234B (en) * 2022-03-14 2023-10-27 中天宽带技术有限公司 Data processing method, device and server
CN115226044B (en) * 2022-07-15 2023-07-18 重庆邮电大学 Multicast routing method and system in NFV network

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107332913A (en) * 2017-07-04 2017-11-07 电子科技大学 A kind of Optimization deployment method of service function chain in 5G mobile networks
CN107925677A (en) * 2015-09-26 2018-04-17 英特尔公司 For unloading the technology of data object replication and service function chain management
CN108260169A (en) * 2018-01-26 2018-07-06 重庆邮电大学 A kind of service function chain dynamic deployment method ensured based on QoS
CN109981438A (en) * 2019-03-22 2019-07-05 大连大学 A kind of satellite network load-balancing method towards SDN and NFV cooperation deployment frame
CN110505082A (en) * 2019-07-26 2019-11-26 国家电网有限公司 A kind of NFV service chaining mapping method towards cost and QoS

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6398999B2 (en) * 2014-02-06 2018-10-03 日本電気株式会社 Network system, network control method, and control apparatus
US10129186B2 (en) * 2016-12-07 2018-11-13 Nicira, Inc. Service function chain (SFC) data communications with SFC data in virtual local area network identifier (VLAN ID) data fields
CN110178342B (en) * 2017-01-14 2022-07-12 瑞典爱立信有限公司 Scalable application level monitoring of SDN networks
CN110198234B (en) * 2019-05-15 2021-11-09 中国科学技术大学苏州研究院 Method for jointly deploying functions of virtual switch and virtual network in software defined network

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107925677A (en) * 2015-09-26 2018-04-17 英特尔公司 For unloading the technology of data object replication and service function chain management
CN107332913A (en) * 2017-07-04 2017-11-07 电子科技大学 A kind of Optimization deployment method of service function chain in 5G mobile networks
CN108260169A (en) * 2018-01-26 2018-07-06 重庆邮电大学 A kind of service function chain dynamic deployment method ensured based on QoS
CN109981438A (en) * 2019-03-22 2019-07-05 大连大学 A kind of satellite network load-balancing method towards SDN and NFV cooperation deployment frame
CN110505082A (en) * 2019-07-26 2019-11-26 国家电网有限公司 A kind of NFV service chaining mapping method towards cost and QoS

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
Joint Optimization of Chain Placement and Request Scheduling for Network Function Virtualization;Qixia zhang et al.;《IEEE ICDCS》;20170717;全文 *
Orchestrating Virtualized Network Functions;Faizul Bari et al.;《IEEE TSNM》;20160513;第1-5节 *
一种基于动态规划的vEPC服务功能链部署方法;王琛等;《计算机应用研究》;20180731;全文 *
面向多业务需求的NFV和SDN融合的资源优化算法;朱晓荣等;《通信学报》;20181130;全文 *

Also Published As

Publication number Publication date
CN111385202A (en) 2020-07-07

Similar Documents

Publication Publication Date Title
CN111385202B (en) Route distribution method based on virtual network function
CN108260169B (en) QoS guarantee-based dynamic service function chain deployment method
CN108566659B (en) 5G network slice online mapping method based on reliability
CN109818786B (en) Method for optimally selecting distributed multi-resource combined path capable of sensing application of cloud data center
CN108965014B (en) QoS-aware service chain backup method and system
CN107454019B (en) Dynamic bandwidth allocation method, device, equipment and storage medium for software defined network
CN111538570B (en) Energy-saving and QoS guarantee-oriented VNF deployment method and device
CN112260950B (en) Cloud storage network multicast stream scheduling method based on service priority differentiation
CN110113761B (en) Deployment method and device of stream data processing application in edge computing network
CN106537824B (en) Method and apparatus for the response time for reducing information centre&#39;s network
CN100534059C (en) Method for overcastting network router by optimized tree topology
Gong et al. Revenue-driven virtual network embedding based on global resource information
CN105677447B (en) Time delay minimization of bandwidth virtual machine deployment method in distributed cloud based on cluster
CN105681153A (en) Virtual network mapping method and device
CN111885493B (en) Micro-cloud deployment method based on improved cuckoo search algorithm
Botero et al. A novel paths algebra-based strategy to flexibly solve the link mapping stage of VNE problems
CN113163498B (en) Virtual network resource allocation method and device based on genetic algorithm under 5G network slice
CN107979545A (en) A kind of mapping method of virtual network based on nodal community
CN109412963A (en) A kind of service function chain dispositions method split based on stream
CN107124303A (en) The service chaining optimization method of low transmission time delay
CN109067920A (en) A kind of load balancing and method for routing for server content update
CN114071582A (en) Service chain deployment method and device for cloud-edge collaborative Internet of things
Di et al. Efficient online virtual network mapping using resource evaluation
Shi et al. Coflow scheduling in data centers: routing and bandwidth allocation
CN117097806A (en) Micro-service call graph deployment and request route joint optimization method and system

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant