WO2012055631A1

WO2012055631A1 - Procedure to set up routes over the transmission network efficiently

Info

Publication number: WO2012055631A1
Application number: PCT/EP2011/065912
Authority: WO
Inventors: Mary Luz Mouronte Lopez; María Luisa VARGAS MARTI; Cesar Pascual Velazquez; José Angel RUIZ TOBALINA; Francisco Javier Ramos Gutierrez
Original assignee: Telefonica, S.A.
Priority date: 2010-10-25
Filing date: 2011-09-14
Publication date: 2012-05-03
Also published as: ES2385011A1; ES2385011B1

Abstract

Method, system and computer program to build routes from a know origin, destination and intermediate network components (such as equipments, ports, etc) over a multi-vendor transmission network, and supported over different network layers in order to establish end-to-end routes and, when necessary, providing path protection mechanisms.

Description

PROCEDURE TO SET UP ROUTES OVER THE TRANSMISSION NETWORK

EFFICIENTLY

D E S C R I P T I O N FIELD OF THE INVENTION

The present invention is related to the telecommunications network management area and the set up of routes given an initial configuration, specifically the trail generation over the different layers in the transmission network. These trails can be the support for different transmission technologies.

STATE OF THE ART

The telecommunication management network covers a wide range of application functions, for supporting all the management tasks a telecommunication network requires. The defined management network can have different sizes, from a connection between a management system and a network element to huge networks than can connect many different kinds of system and network elements. However, the works for defining a standard make slow progress. If it is considered the present situation in the standardization field, it is worth mentioning the works that are being carried out by ITU-T XI and XV groups. These groups are going deeper in the object and messages modeling and defining. One of the biggest efforts, being ahead of the ITU-T works, is the new definition and expansion of the management services. The first works for standardizing the network management where carried out by the

SG-IV (Study Group IV), ITU-T, between 1985 and 1988. They tried to define and develop a management interface system for public telecommunication networks and equipments. The first main result was recommendation M.30, published in the blue book at 1989. In the next period, between 1989 and 1992, Rec. M.30 clearly identifies OSI system management as the foundation for the TMN

(Telecommunication Management Network) standard. This recommendation changed to M.3010. Therefore, services and protocols included in OSI system management (Recs. X.700 Series) are at this moment a subset of the network management capabilities provided by the TMN. Finally, the TMN management recommendations defined by ITU-T (M.3000 series) establish all the solutions for telecommunication service exploitation in all the life cycle, beginning at planning and including administration, provisioning, installation, maintenance and operation.

The current line of work is based on recommendation M.3200 (Management Services and Telecommunications Managed Areas: Overview) [ITU-T M.3200, 92].

Rec. M.3200 includes a standard description for the management services that allows identifying the location of the functional areas for every service in the different management layers in which the TMN model is divided. There has been an important effort in the patent field to adapt the theory to the real problems in the information transfer. Particularly, there are four big patent groups related to this invention:

In the first place, patents related to lookup of the better route, e.g., US Patent 7330440: "Method and apparatus for constructing a transition route in a data communications network". In general, this group of patents is focused on obtaining a temporary route without input information, but present invention is focused on translating the prefixed route set in external systems— expressed in terms of link connections, ports and transmission media— to the proper route in the network. Secondly, patents related strictly to transmission, in SDH or WDM networks, e.g.,

US Patent Application 20050180420: "Transmission network system". This invention relates to a transmission network system, and more particularly, to a transmission network system suitable for use with a synchronous network, such as an SDH (Synchronous Digital Hierarchy) or a SONET (Synchronous Optical Network). In such patents, the main focus is the protocols and the way the information flows over the network. However, the subject matter of present invention is focused not in such concept but in the network structure, trying to define the route according to the network capabilities and characteristics but not the information structure. Thirdly, patents related to the network management, e.g., US Patent 6192034:

"System and method for network integrity management". This invention relates in general to the field of electronic commerce, and more particularly to a system and method for network integrity management. Nevertheless, present invention is only focused in building routes in a transmission network. Lastly, patents focused on the trail protection, e.g., US Patent 7380017: "Route protection in a communication network". This invention relates to methods and arrangements for providing recovery from faults in a communications network and for calculating protection paths in such a network. The invention further relates to a network manager arranged to perform such path calculation. Although present invention infers necessary entities to protect paths— such as SNCPs or MSPs— , it does not explain technical details about how network should be protected.

Presently telecommunication network operators demand specific management capabilities to the suppliers, so the results are propriety management solutions that are much related to the equipment technical features. In this situation, each supplier offers solutions only for the own dominion, which is not good for any network operator. Additionally, due to strategic reasons based on the network exploitation business, multi-vendor environment is a strategic objective for the telecommunication network planning. This way, if suppliers only give management solutions for their equipments, planning a complex network entails a difficult decision: to keep an only supplier or to define management islands, one for each supplier.

Furthermore, the goal of management architecture is to provide a global management solution for all the transmission resources and to define and scenario for the co-existence of multi-vendor subnetworks. In this case, the internal perspective for the network management is based on two principles: to achieve a multi-vendor management environment and to offer a global and integrated network management. On the other hand, there is an external perspective for the management, focused on the business processes, which main goals are to make easier the circuit service provisioning in a fast and efficient way, shaping to the customer necessities.

In a transmission network, due to the high number of suppliers and the continuous appearance of new equipments with more features, it does not feel reasonable to depend on an only supplier, so the multi-vendor environment is the usual way in a big transmission network operator. A global and integrated management requires a solution that can isolate the system of the equipment technology and supplier. Global and integrated management in a multi-vendor environment needs an integrator system, which connects to the subnetwork management systems through management interfaces. A designed system offers a simplified and uniform view of the network resources to the managers -through navigation capacities into the subnetwork management systems- and isolates the supplier management solutions.

This system must include functions for designing paths, set them up and configure their protections. Paths will be created among two or more free access points (APs), i.e., they do not belong to other path. The paths will have different configurations (unidirectional, bidirectional and point-multipoint) and protections (no protected, subnetwork protection and trail protection).

Network Architecture in present invention

A layer network is the whole set of similar access points, which can be linked for purposes of information transfer. Into a layer network, access point associations can be created and released by means of a layer management process that modifies their connectivity. A layer network is integrated by subnetworks and links between them. A subnetwork is the complete subset of similar connection points, which can be associated for a specific information transfer. Into a subnetwork, connection point associations can be created and released by means of a management process that modifies their connectivity. Generally, subnetworks are integrated by smaller subnetworks and links between them. The minimum recurrence level is the connection matrix in a network element. Finally, a link is the subset of connection points into a subnetwork that are associated to a subset of connection points into another subnetwork for purposes of information transfer between them. The network management process cannot create or release the set of connection point association that define the link. The link represents the topological relation between two subnetworks. In general, it is used for describing the association between the connection points in two different network elements. In terms of layering, the minimum recurrence level for a link is the transmission medium. Figure 1 describes the topology for a layer network in term of access point associations through subnetworks and links. The transmission entities provide a transparent information transfer among reference points in a layer network. That is, the information does not suffer any modification between input and output but the degradation caused by the transfer process. Depending on the capacity for supervising the integrity of the transferred information, there are two basic entities: connections and trails (also known as paths). Connections are divided into network connections, subnetwork connections and link connections, according with their topological component:

Network connections are able to transfer information in a transparent way through a layer network. They end in Termination Connection Points (TCP). This entity represents the higher abstraction level in a layer, and it is integrated by a chain of subnetwork connections and link connections. There is no information about integrity of the transferred information, but information about connection integrity can often be deduced from other sources.

Subnetwork connections are able to transfer information in a transparent way through a subnetwork. They end in connection points located at the subnetwork frontier. This entity represents the association among Connection Points (CP), and usually, it is integrated by a chain of subnetwork connections associated to a lower level and link connections. The matrix connection is the lowest level, and it represents a connection into an individual matrix belonging to a network element. Figure 2 shows a Link Connection between two subnetworks.

Link connections are able to transfer information in a transparent way through a link between two subnetworks. They end in connection points located at the frontier between the link and a subnetwork. This entity represents the association between both CPs. Link connections are defined through trails in the server layer network which said trails are the entities associated to the specific information transfer between access points. According to this, they are defined by the association between access points and additional information regarding to the integrity of the information transfer.

There are two treatment generic functions: adaptation and termination. They work together at the layer frontiers, and they are defined by the information processing they do between input and output. The adaptation functions adapt the specific information belonging to a client layer network so it can be transmitted through the server layer network. Examples of the interlayer adaptation functions are coding, speed variation, alignment, justification and multiplexing. The trail termination functions provide data related to the information transfer into a trail. This is usually achieved by inserting additional data by the trail termination source function that it is supervised at the trail termination drain function. Figure 3 shows a trail which it is defined by a network connection and trail termination functions among TCP and access points. Figure 4 shows the transport processing functions symbols used in next figures (Adaptation Function, Termination Function and Reference Point).

A trail is a transmission entity that it is integrated by a relation among trail terminations and a network connection, as Figure 5 shows, and it is a special layer network capacity. As can be seen in the functional model of Figure 5, the tie between an entity or function output and other entity or function input is defined through a reference point in the layer network. There are three kinds of reference points: access point (AP) (between them a Trail is established), connection point (CP) (between them a Link Connection is established) and termination connection point (TCP) (between them a Network Connectionl is established). In this invention the nomenclature will be the following: CTP (connection termination points) represents the signal state at a CP, and TTP (trail termination point) represents the signal state at a TCP. As you can see in figure 5, there are trails in the Client Layer and in the Server Layer, which contains a Server Layer Network.

Partitioning and Layering concept

Transmission networks can be split in independent layer networks, where adjacent layers are related through a client/server association. Each layer network can be split again so the internal structure in that layer is shown. Figure 6 shows the layering and partitioning concepts applied to the subject matter of present invention. The vertical layering is composed by a Client Layer Network, a Specific Path Layer Network and a Transmission Media Layer Network. The partitioning concept can be split into two connected concepts: subnetwork partitioning, which describes the topology, and network connection partitioning, which describes the connectivity. A subnetwork describes only the capacity to associate some CPs or TCPs; it does not describe directly the components topology that is used to design the network. In general, any subnetwork can be split into smaller subnetworks, connected through links. The way the smaller subnetworks and links are connected describes the subnetwork topology. It can be expressed as:

Subnetwork = Smaller subnetworks + links + topology

So, if it is used the partitioning concept, any layer network can be broken down in a recurrent way till it is reach the desired detail level. Usually, this detail level includes the network elements with their connection matrixes, so a layer network can be a flexible connection.

On the other hand, the layering concept into the transmission network is based on each layer network can be classified according to similar functions; designing and operating each layer separately is easier than doing it if the transmission network were a single entity; so, a stratified network model can be useful to define the objects the Telecommunication Network Management (TMN) can manage; each layer network owns operation and maintenance capacities, as automatic commutation and restoration in a failure situation, or protection in case of anomalies or failures. These capacities reduce to the minimum level the operation and maintenance that must be performed externally, without impact in other layers; a layer can be added or modified without impact in other layers and each layer network can be defined independently.

The network connection is a special case corresponding to the widest network capacity into the layer network. A network connection can be partitioned in the same way than a subnetwork, as Figure 7 shows. In general, a subnetwork connection can be partitioned through the sequential combination of subnetwork (SNC) and link (LC) connection, as indicated in the following expression:

Network connection = TCP + subnetwork connections + link connection + TCP Each subnetwork connection can be split in a sequential combination of subnetwork and link connection according to the following schema:

Subnetwork connection = connection point + smaller subnetwork connections + link connections + connection points

Figure 8 shows the client/server association between adjacent networks, in which a trail in the server layer network offers a link connection to the client layer network. The adaptation concept described before allows this relation. So, from a functional point of view, the adaptation function into the transmission network is located between two different layers, as shown in Figure 5. However, from an administrative point of view, the adaptation function belongs to the trail into the server layer network. Figure 9 shows the layered transmission network model used in present invention. The features in the model are:

- The relation between two adjacent layers is a client/server one.

- Each layer has its own operation and maintenance capabilities;

and there are three kinds of layer networks:

Client layer networks, which provide telecommunication services to the costumers. These services include circuit switching, packet switching and rented lines. There are different circuit layer networks according to the services provided. Here the Client Layer is included.

Path Layer Network, which support different kinds of circuit layer networks. If we are talking about the Synchronous Digital Hierarchy (SDH), the network where we are going to apply the invention, there are two path layer networks: lower order path layer network (LOP) and higher order path layer network (HOP). The lower order path layer network transports 2Mb/s user data flow into virtual containers called VC- 12 and 34Mb/s-45Mb/s user data flow into virtual containers called VC-3. This layer network uses the services provided by the virtual containers called VC-4, which belong to the higher order path layer network. The higher order path layer network provides service to the lower order path layer network and the circuit layer network (140Mb/s). In these path layer networks, connectivity can be managed. Transmission media layer networks, which depend on the transmission media, e.g. optical fiber. The transmission media layer networks split in section layer networks and physical medium layer networks. Section layer networks include all the functions which provide data transfer between two nodes. Physical media layer networks are related to the real media (fiber, copper wire...) which support a section layer network.

Protection features

Subnetwork Connection Protection Schema, the subnetwork connection protection (SNCP) is a dedicated protection mechanism that replaces a working subnetwork connection by a protecting subnetwork connection when the working one fails or has a degraded quality. The subnetwork connection protection can be used in any physical structures: mesh, rings or a mix of them. Trail Protection Schemas. in a trail protection, a working trail is replaced by a protecting trail when the working one fails or degrades. The failure or degradation is detected by the trail termination functions, and the switching is carried out by a protection matrix, located into the trail protection sub-layer. There are two types, according to the layer where the protection is locates: Multiplex Section trail protection (MS-Trail Protection) and higher order trail protection (HO-Trail protection).

MS-trail protection gives end-to-end protection to a MS-Trail, expanding the termination point function for creating a MS-Trail protection sub-layer. There are two MS-Trail protection schemas: lineal protection (MSP) and shared protection rings (MS-Spring).

HO-Trail protection gives end-to-end protection to higher order paths, expanding the termination point function for creating a HO-Trail protection sub-layer. In these schemas, the failure detection is carried out by the Higher Order Path Termination function (HOPT) and the protection matrix, included in the protection sub-layer, makes the changes. The changes can trigger a protection switching in more than a Network Element. Both of the previous protection schemas include two entities that manage the protection: protection group, which represents the intelligence for managing the protection; and protection unit, which describes the relations among the protection resources.

SUMMARY OF THE INVENTION

This invention is based on an analysis of the transmission network in order to identify some generic functionalities that do not depend on the technology they are implemented. The method of present invention describes the network functionalities in base a reduced number of architectural components that can be defined by according to the information treatment they carry out, or according to the relations they establish among other components. The transmission network can be described in term of the existing associations among the network points. It have been defined three topological components to provide the most abstract description for a network in terms of topological relations among similar reference point sets: layer of the network, subnetwork and link; describing the network logical topology through these three only elements. Also, in order to simplify the description, the transmission network model is based on the concepts of layering and partitioning in each layer, so a substantial recurrence level can be achieved.

This invention describes a method to build routes from a known origin, destination and intermediate elements (such as equipments, ports...) over a transmission multi- vendor network and over different layer networks by generating the necessary logical entities to establish end-to-end routes. It is done from physical resources

(ports and transmission media) and logical ones (link connections) which are supported by server layer trails and which they have been established. Thus the invention provides a method to build trails and circuits over transmission networks, using a provided minimum and disordered set of network administrative information (such as ports, device interfaces, transmission ability from a determinate equipment, etc) and building a continuous network layer for client signal; but also hiding the complexity of the network layers involved in the route. The key idea is to build routes from a minimum set of data and from it determinate the necessary logical entities and resources for performing an end-to-end route. The minimum information data is named initial route and it is integrated by route components (ports, transmission media and link connections) which they must be part of the final end-to-end route and may be given in a disordered way. The method of this invention is based on the analysis of said initial route by putting these resources into sorted groups named route segments and adding other route components not included in said initial route but necessary for end-to-end fulfilment. These new route components are obtained from known rules based on the requirements of ending each involved network layer in an element of initial route and on the relations between the different layers.

From said route segment, the method calculates the logical entities which have to be generated and the resources to be used, in order to include them in the initial route. In this way, the method generates all trails in the layers at each component of the route. There is a requirement that the termination points in the source and target ports of each said segments must be known. This operation hides the complexity of the different network layers and simplifies the end-to-end performing. In other aspect of present invention each route component is characterized by the type of route where it is, which may comprise a working route, which is assigned to transfer the signal, or a protecting route, which is assigned to assure the availability. When a fail or degradation occurs the signal is switched and transferred across the protecting components. If a component is assigned to protecting route then the analysis determines the type of protection, SNCP (SubNetwork Connection

Protection) or MSP (Multiplex Section Protection).

Finally, the method occupies the components in the new route. Occupancy of network entities, if they are already available, is effectuated in this stage rather than building new ones.

Summarizing, this invention features: - It generates trails over the different network layers according to an integrated vision of a transmission network and hiding the characteristics of its elements.

- It builds end to end trails across different technologies and providers.

- It increases the efficiency in the provision and end-to-end performing, because it reduces the necessary information in the operations of establishing the trails over the layers in the transmission network.

BRIEF DESCRIPTION OF THE DRAWINGS To complete the description and in order to provide for a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate a preferred embodiment of the invention, which should not be interpreted as restricting the scope of the invention, but just as an example of how the invention can be embodied. The drawings comprise the following figures:

Figure 1 describes the topology for a layer network in term of access point associations through subnetworks and links.

Figure 2 shows a Link Connection between two subnetworks.

Figure 3 shows a trail which it is defined by a network connection and trail termination functions among TCP and access points.

Figure 4 shows the transport processing functions symbols used in this invention. Figure 5 depicts a functional model showing the reference points in the layer network: access point (AP), connection point (CP) and termination connection point (TCP).

Figure 6 shows the layering and partitioning concepts applied in present invention. Figure 7 depicts a partitioning of a network connection in the same way than a subnetwork.

Figure 8 shows the client/server association between adjacent networks, in which a trail in the server layer network offers a link connection to the client layer network.

Figure 9 shows the layered transmission network model used in present invention. Figure 10 depicts a general flowchart from the method, showing a preferred embodiment of this invention.

Figure 1 1 shows method's stage "Sort Initial Route" flowchart. Figure 12 shows the procedure "Make sorted ubication list" from "Sort Initial Route" stage in a preferred embodiment of this invention.

Figure 13 shows the procedure "Analyze route from ubication" from "Sort Initial Route" stage in a preferred embodiment of this invention.

Figure 14 shows procedure's flowchart "Treat link connection to another ubication" from "Analyze route from ubication" step in a preferred embodiment of this invention. Figure 15 shows procedure's flowchart "Find Path to CTP" from "Treat link connection to another ubication" step

Figure 16 depicts an example of the previous procedure in a preferred embodiment. Figure 17 shows procedure's flowchart "Find Path from CTP" from "Treat link connection to another ubication" step

Figure 18 depicts an example of the previous procedure in a preferred embodiment.

Figure 19 shows procedure's flowchart "Treat port" from "Analyze route from ubication" step in a preferred embodiment of this invention.

Figure 20 shows procedure's flowchart "Process SNCP protection".

Figure 21 depicts an example of Process SNCP protection.

Figure 22 shows the method stage "Generate Logical Entities" flowchart.

Figure 23 shows procedure flowchart from "Generate Logical Entities" stage called

"Treat Link Connections in a Partitioned Port".

Figure 24 shows procedure's flowchart from a "Generate Logical Entities" stage called "Path termination".

Figure 25 shows procedure's flowchart from "Generate Logical Entities" stage called "Treat Partitioned Port".

Figure 26 shows method's stage "Generate Route" flowchart.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

This invention is obviously not limited to the specific embodiments described herein, but also encompasses any variations that may be considered by any person skilled in the art (for example, as regards the choice of components, configuration, etc.), within the general scope of the invention as defined in the appended claims.

In the context of the present invention, the term "comprises" and its derivations (such as "comprising", etc.) should not be understood as excluding the possibility that what is described and defined may include further elements, steps, etc. In this text, the technical term "ubication" has been used. It has the same meaning as the term "location" or "situation", so in the text and drawings the term "location" can be used instead (that is with the same meaning) the term "ubication".

Figure 10 shows the general procedure flowchart operations; in a preferred embodiment of this invention, which it comprises the stages of Sort Initial Route 2, Generate Logical Entities 3, and Generate Route 4. The method is based in introducing a set of network data call Data Input 1 which is a set of network components comprising logical and physical components (networks ports, equipments, links...) of which the end-to-end route must be part of, so the final goal of the method is to build the route according to this set of minimum network components provided.

Sort Initial Route 2 sorts out in the logical order said route path components given in Data Input 1 . Sorting is done in base of the ubication (i.e. location) of these network components. In this stage continuous route segments are built, and they comprise working and protecting components. Also if a protecting route exists, then the type of protection is decided. Finally in this stage it is assigned the appropriate transmission media to each segment generated previously.

From said segments, Generate Logical Entities stage 3 generates all necessary trails and the corresponding logical entities to carry the signal through the different network layers, according to rules at source and target ports and restrictions regarding the network layers where the trails are supported. Each trail is integrated by a set of subroutes and these trails are the output from this stage.

Finally the Generate Route stage 4, from said trails generated in the previous stage, performs the actions to build the end-to-end route, where logical entities and route components are generated or occupied. Also if the trail may carry client signals then it is built the structure which supports server and client relations. Occupancy of network entities, if they are available, is effectuated in this stage rather than building new ones. These entities and network components are physical: ports and transmission media, and logical: trails, link connections, subnetwork connections, termination points, protecting groups and protecting units.

A detailed description of each stage follows:

DATA INPUT

The procedure is initiated with "Data Input" 1 which it comprises data of part of the route prefixed expressed in terms of link connections, ports and transmission media of the circuit or trail. Data Input are signal rate and "initial route" which it is constituted by:

physical entities:

^■ ports

^■ transmission media

and logical entities:

■ link connections

which they must be part of the end-to-end route; and wherein its components may belong to heterogeneous technologies and may be given in a disordered way; it means not following the logical sequential order of the route. Each component is characterized by the type of route where it is, working or protecting. Data input also comprises the rules and restrictions dealing with network layers, client and server relations between layers, and network layers for each type of port in the route.

STAGE 2. SORT INITIAL ROUTE

The method of the present invention in this preferred embodiment continues with the stage "Sort Initial Route". From the route components (initial route) of Data Input 1 , it is put said components into ordered groups and built continuous route segments which include working and protecting components; and if there is a protecting route, then it is deduced the protection type which must be built.

These segments are comprised by routes, wherein a route is comprised by a type of route (working or protected SNCP), a source port, a target port, a ports set, a link connection set and a transmission media set. Each segment always includes a working route and the method also builds a protecting route for each SNCP in the initial route. Flowchart of operations from this stage is presented in Figure 1 1 . Each component has a relative order and an indication about the type of route where it is. The process of sorting the route components is based on the ubication (i.e. location) concept, which it is related to the place where a set of equipments is located. The transmission media establishes a communication channel between two locations and optionally, it might pass by a series of intermediate locations.

First step in this method's procedure determines the list of ubications (i.e. locations) which are crossed by the prefixed route given in the said initial route. A sorted ubication (i.e. location) list is performed for working route 1 101 and, if appropriate, for protecting route 1 102.

Figure 12 shows a diagram about this operation (sorting ubications). It sorts them with the criteria:

- End ubications in the route, A and Z, only are communicated with a single ubication (i.e. location) which may be or not an intermediate ubication (i.e. location).

- Intermediate ubications in the route, which are communicated with other two different ubications, one from which the signal is received, and other where the signal is sent to.

- There are two communication ways between ubications: through link connections which are clients of server layer trails or through physical trails which link end ports. Figure 12 process is as follows:

The first link connection (1201 ) is obtained, if it exists (1202), the first port is obtained (1203). If it exits, it is checked if the port is in the A or Z end ubication (i.e. location) of the link connection (1205). In positive case, it is checked if the A and Z end of the link connection is in the same ubication (i.e. location) (1206). If yes, the link connection A and Z end ubication (i.e. location) is added to the ubication (i.e. location) list (1207) and then the next link connection is obtained (1208) and the process returns to step 1202.

If the in step 1205 the answer is no, the process checked if the port ubication (i.e. location) is in the ubication (i.e. location) list (1209); if yes, the next port is obtained (1210) and the process checks if it already exits (1204). If not, it is checked if it exists any link connection with A or Z end in port ubication (i.e. location) (121 1 ), if yes, the next port is obtained (1210), if not, the isolate port ubication (i.e. location) is added to ubication (i.e. location) list and the next port is obtained (1210). If in step 1206, the answer is no, the next port is obtained, and it is checked if it already exists (1214) if yes, we check if the port ubication (i.e. location) is equal to the ubication (i.e. location) of the link connection A end (1215) or Z end. In the first case, the link connection A end ubication is first added to the ubication list and later, the Z end ubication is added to the ubication list. In the second case, the link connection Z end ubication is first added to the ubication list and later, the A end ubication is added to the ubication list. In both cases the process returns to step 1208. If the port ubication (i.e. location) is not equal to any of the A or Z ends ubications (i.e. locations), the next port is obtained (1219) and the process returns to step 1214.

If link connection does not exists (1201 ), the first port is obtained (1220) and it is checked if it exists (1224). If not, the process ends (1225). If yes, the port ubication is added to the ubication list (if it is not already in the ubication list), the next port is obtained and the process returns to step 1224.

Afterwards, the "Sort initial Route" process processes said list of ubications. To do that, for each ubication in the route, the ubication ends of the link connections with one end in an ubication and other end in a different ubication are obtained. The first ubication end is obtained (1 104) and is processed and then the second ubication end is obtained (1 105) and then is processed (1 106). This processing is called

"Analyze Route from ubication" 1 106 and it is explained in figure 13. It involves:

First, the method processes the link connections which have an end in current ubication and end in other different one 1301 in a procedure called "treat link connection toward another ubication" 1305. The goal is to obtain a continuous route segment.

Figure 14 shows the flowchart of this procedure in this preferred embodiment of the invention. It begins with processing the route from the Connection Termination Point toward the next ubication in a subprocedure called "Find Path to CTP" 1404 and then, "Find Path from CTP" 1405. They set continuous segments to carry the signal among two ports (A and Z) by establishing a sequence of link connections. Using figures 16 and 18 as reference, "Find Path to CTP" 1404 determines the part of the segment of the left hand side from the "Reference CTP" to the "SDH Port 1 " (Path A end); and "Find Path from CTP" 1405 determines the part of the segment of the right hand side from "Reference CTP" to the "SDH Port 2" (Path Z end in this example).

Find path to CTP

Known the reference CTP, it searches the first untreated link connection 1501 terminated in a CTP (another than the reference CTP) on the same equipment as current reference CTP (1502, 1503, 1506 loop). It is added the link connection to path 1504, then it is marked as treaty, then it is set its another end CTP as reference CTP 1505 and finally it is repeated this process.

If is not possible to find a link connection 1502, it searches the first untreated port 1507 on the same equipment as current reference CTP 1509 and it is set as A end path 1510. If it is not on the same equipment as the current referent CTP, the next not treated port is obtained. If no port is found, it is set null as path A end 1508.

Figures 15 and 16 show the flowchart of Find Path to CTP and an illustrative example respectively.

Find Path from CTP

Then, it searches the route outside of the current ubication in other subprocedure

"Find Path to CTP". Known the reference CTP 1701 , it searches the first untreated link connection terminated in a CTP on the same equipment as current reference CTP (1702, 1703, 1706 loop). It is added the link connection to path 1704, then it is marked as treaty, then it is set its another end CTP as reference CTP 1705 and finally it is repeated this process.

If is not possible to find a link connection 1702, it searches the first untreated port 1707 on the same equipment as current reference CTP 1709 and it is set as Z end path 1710. If no port is found, it is set null as path Z end 1708. Figure 17 show the flowchart of Find Path from CTP and figure 18 depicts an illustrative example. Finally it is joint both routes to constitute a continuous segment which is added to the set of segments 1406 which will be the input for the next stage in the method "Generate Logical Entities" 3.

Following with the process "Analyze route from ubication" (figure 13), the next link connection to another ubication is obtained (1306) and if it exists (1304) it is treated with the process "Treat link connection to another ubication" (figure 14) explained before.

Then, the ports in current ubication not even treated 1302 are processed, in a procedure "Treat port" (Figure 19). The process "Treat port" is repeated for the next not treated port in reference ubication (1309) until there are no more ports in the reference ubication.

The "Treat Port" process determines the sequences of continuous segments from the ports and link connections into the current ubication. In order to do that, the reference port is set as path A end and it is marked as treaty (1901 ). Then, the first not treated link connection is found (1902) and it is checked if said link connection ends in the same equipment as the current reference port (1904). If not, the next not treated link connection is obtained (1907) and checked again. If yes, said link connection is added to the path (1905), it is marked as treaty and the CTP end of said added connection which is not in the current TP equipment is set as reference

CTP (1906) and the process returns to step 1902.

If it is not possible to find a first link connection not treated (1903), the fist port not treated in the same equipment as the current port is found (1908, 1909, 1910, 1912) and said port is set as Z end of the path (191 1 ). If no such a port is found, null is set as Z end of the pathe (1913).

Finally, the link connections which have both A or Z ends in current ubication and which have not been treated yet 1303 are proccesed. These link connections are processed 131 1 with the same rules as the search of route from "treat link connection toward another ubication" 1305 (i.e. repeating the process "Find Path from CTP" for the CTP of said link connection). The process is repeated to the nest link connection not treated (1312) whose A or Z end ubications are in reference ubication until there are no more link connections (1313).

Next step in this "Sort initial route" stage 2, is to develop and treat protections: Multiplex Section Protection (MSP) 1 108, and SubNetwork Connection Protection (SNCP) 1 109. The MSP processing implies to process the protecting route with the same considerations as the working route. It is obtained an ubication list that contains the end ubications of protection route. These end ubications must be the same end ubications of working route. From first ubication, protecting route is processed as described above in "Analyze route from ubication" 1 106 and it is generated new MSP segments that provide a protecting route between the same end equipments of working route.

The treatment of SNCP (shown in figure 20) implies to get the continuous segments of the protection route and to identify the working route segments where they are. A new ubication list is obtained from the end ubications of protecting route. From the first ubication, protecting route is processed as described above in "Analyze route from ubication" 1 106, then the next ubication is got and analyzed. As result, new SNCP segments are generated. Each of them represents a different protection route. Next step is to assign each SNCP segment as a protection route of a working segment. For assigning a SNCP segment route to a working segment, A and Z SNCP end equipments must belong to working segment. To do that, the first SNCP segment and the first segment in working segment lists are obtained and it is checked if the SNCP A and Z ends belongs to the current working segment. If not, the next working segment is obtained and it is checked again. If yes, the SNCP segment is assigned as working segment protecting rout and the next SNCP segment is obtained.

Figure 20 shows the flowchart of SNCP protection and Figure 21 depicts an illustrative example with three working segments (1 , 2 y 3) and two SNCP protection routes (A y B), SNCP route A goes from equipment B to equipment F, both equipments belong to working segment 2; and route B goes from equipment K to L, both equipments belong to working segment 3.

Finally in this stage 2 it is treated the transmission media 1 1 10. The transmission media processing implies to assign media to the correct segment generated previously. It is based on transmission media end ubications and ubications included in each seqment. For each transmission media, it is searched a segment that includes one of the end ubications of media. If one segment is found, media is added to segment. If no segment is found, end media ubications are searched as end ubications of other media included in each segment. The process is repeated until all media are treated.

STAGE 3. GENERATE LOGICAL ENTITIES (3)

The input to this stage is a sorted route from previous stage comprised by route segments. From this data, the stage "Generate logical entities" 3 performs the operations of generating the actions to build all necessary trails over the different layers to carry the signal. It is done by rules in the source and target ports (according to its type) and by restrictions in the network layers where these trails are supported. The output will be a route supported by a set of different network layer trails, including their own routes, which are needed to transfer signal end-to-end.

Network layers might have continuity and simplicity in the circuit layer. This means that the route must be continuous end-to-end in each layer. In physical network layer the transmission media continuity is supposed. Simplicity in circuit layer in this case refers to ports performing the termination connection and trail termination functions. These ports are named unpartitioned ports. A partitioned port supports several layers with its different trails and obviously supporting different link connections and client routes which fulfil the requirements and restrictions. On the other hand, an unpartitioned port supports only a single layer.

The procedure includes the route components in the specific trail depending on their network layer. Each trail is integrated by a set of subroutes with a type (working, path protection or SNCP protection). Each subroute has five sets: a ports set, a termination points set, a link connections set and a transmission media set. Figure 22 details "Generate logical entities" stage. From processing the source and target ports in the route it is added a new working subroute 2202, the first working segment is obtained and the source port is set as the source port of the first working segment 2204 and the target port is set as the target port of the last working segment. Both ports must allow the trail to end (It means that the port and the signal rates must be the same). If the port can be partitioned 2205 then, it must be configurable to include a termination point where the trail ends 2208. If one of them does not allow the trail to end then the procedure generates a new port which will be a source port or a target port.

From the source port and the first segment this subprocess is repeated for all segments, therefore this method's steps depend on whether the port can be partitioned or not.

If the port can be partitioned 2205 (it means that said port supports several layers):

If the segment belongs to circuit layer and it is a border port of the trail 2206, then the procedure adds the port to subroute 2207.

The procedure gets first link connection and network equipments where it ends 2208.

If a link connection ends in the same equipment than the port then the procedure continues with operations "Treat LCs in partitioned port" 2210 and the next ports in the ports set of working segment as added to the ports set of the current suborute (221 1 ). Otherwise, the procedure continues with operations "Treat partitioned port" 2212.

On the other hand, if the port cannot be partitioned 2205:

The procedure adds the port to the subroute 2214.

If the link connection set is empty then the procedure adds all included ports to the subroute 2224. It also adds transmission media to the subroute 2225.

On the contrary if the link connection set is not empty 2215 then: ■ If first link connection ends in an unpartitioned port 2216 the procedure adds all link connections 2217 and ports included in the set to the subroute 2218. ^■ Otherwise 2216, it checks that the other ports included in the segment are partitioned 2221 . The procedure adds unpartitioned ports to the subroute 2220. When it gets a partitioned port 2221 , if the segment belongs to circuit layer and it is a trail layer border port 2222 then the procedure adds the port to the subroute 2223. Finally, the procedure continues with the operations "Treat LCs in partitioned port" 2210.

These steps are repeated until all segments are processed. To do that, the next segment is obtained 2213. If it is a protecting segment 2227, the process adds a new protecting route in current trail. In any case, the source port is assigned as souce port of the current segment and the process is started again from step 2205 to include the assigned resources. Finally, the general method in this preferred embodiment continues with stage "Generate route" 2230.

Treat Link Connections in partitioned port

Figure 23 shows the operations "Treat Link Connections in partitioned port", where the link connections found are analyzed and processed in order to generate the necessary logical entities. From current trail and port 2301 :

The procedure gets a termination point TTP for the trail 2302 located in the current port. If it exists 2303, then the procedure adds the termination point to the current subroute trail 2304.

If the first link connection cannot be assigned to the trail 2305 then the procedure generates as many trails as are necessary until the link connection can be assigned 2314. This operation considers rules and restrictions about the relations between layers. To do that, for each server layer might which can terminate in port 2306 (otherwise the process is terminated 2337), a new path is built for said server layer . Each built trail/path is added to the trails collection (2308), the new path is assigned as current path (2309), the TTP in the port is obtained 2310 (if it does not exist, it is created 2312), the new TTP is added to the points set in the current subroute and the process returns to step 2305. Then, if the first link connection can be assigned to the current path/trail 2305, the link connection TCP in the same equipment that current port is obtained (2315) and it adds a subnetwork connection to current subroute 2315. The subnetwork connections is integrated by the last termination point included in the subroute and by the termination point of the link connection in the same equipment.

Then it adds the link connection 2316 and the other termination point of link connection 2317 to the trail subroute. The procedure repeats these last two steps until all link connections are processed (repetition of steps from 2316 to 2321 ).

Once all the link connections have been processed (2319), the procedure gets the next port in the ports collection 2322 and it obtains the trail termination point in said port. If it does not exist, it creates the TTP (2325). Then, it adds a new subnetwork connection 2326 between the last termination point included in the subroute 2317 and the trail termination point in the port 2323.

Finally if the segment includes a protecting route 2327 then the procedure adds a new protecting subroute 2328 and it includes the link connection 2329 in the current subroute, it obtains the TCPs of the link connection (2330), it gets the next link connection 2331 and it repeats the actions 2314 and 2315 to add the subnetwork connections 2334.

If new trails collection is not empty (current path is not initial path) then the procedure continues with the operations "Path termination" 2336 (see Figure 24) performing:

Path termination

It generates the final route assigned to the last trail in the collection. These operations are performed by "Generate route" stage 4.

It generates a new action to build a trail and includes it into actions set.

It deletes the trail from new trails collection 2402 and gets the next trail in collection 2404. If there is not a trail 2403 then, the procedure establishes initial trail as current trail 2413.

The procedure adds a new subnetwork connection between last point included in the soubroute and the link connection TCP in the same equipment (2405) and it adds the link connection to the current subroute set (2406)

If current trail can end in last treated port 2407, the TTP in the port is obtained 2408 and then the procedure adds new subnetwork connection 2410 between the last termination point in the subroute and the TTP in the port. If current trail is not initial trail 2412 then the procedure repeats these operations (returns to 2401 ). Otherwise (If current trail cannot end in last treated port 2407), it adds the other termination point of link connection to current trail subroute 2414.

Treat partitioned port

Figure 25 shows the operations of "Treat partitioned port" procedure wherein the ports found and not belonging to a link connection, are analyzed and processed in order to generate the necessary logical entities. From current trail and port 2501 the procedure performs:

First it gets a termination point located in current port in the trail and adds it to subroute trail 2502.

If current trail 2503 is not in the physical media layer then the procedure builds as many trails as layers can end in the last port 2504 until the trail is in the physical media layer. If the server layer can terminate in the port 2504, it creates a new trail in the server layer, it adds the new trail to the set of trails and it sets said trail as current trail. Then it obtains the TTP in the port (2508).

For each trail, it gets termination point in the port 2508 and adds it to trail in the subroute 251 1 .

The procedure gets the next port in the ports set 2512 and adds the termination point where the ports is, to current working subroute 2516. It also adds transmission media to the subroute 2517. If new trails collection is not empty 2518 (that is, current trail is not the initial trail) then the procedure continues with the operations "Path termination" 2519 explained previously. STAGE 4. GENERATE ROUTES

The input data to this stage is a route which is defined by subroutes. A route is integrated by a working subroute, and optionally it also has a protecting subroute. Each subroute may be integrated by link connections, transmissions media, subnetwork connections, termination trail points (TTPs), and ports.

This stage begins ordering the subroutes to process first the working subroute. Then, this stage checks the coherence of the route; the controls are based on the transmission layer characteristics. The types of routes are:

Continuous routes which use termination points. The continuity must exist between all entities in the route. The list of subnetwork connections and the list of link connections cannot be empty.

Continuous routes which use ports. The continuity must exist between all entities in the route. The ports list and link connections list cannot be empty.

Discontinuous routes which use termination points or ports. The continuity might not exist between all entities but it must exist at equipment level.

The first type is shown in the Generate route flowchart (Figure 26); the entities occupation consists of processing the ordered list of entities and building the necessary actions to associate the entity with the trail. If the information of the trail is not right, the process is ended (2602) Otherwise, the process starts selecting a subroute 2603. If it is a working subroute, the sequency of entities to use/occupy (or to generate if there is no available elements) must be first a subnetwork connection 2605, then a link connection 2606 and then other subnetwork connection 2607. The last component must be a subnetwork connection. This is performed this there is no more elements 2608.

If it is a protecting subroute then it may be SNCP or MSP. The occupation sequence are similar to the sequence in working subroute, but it is possible not to have a subnetwork connection as the beginning 2609 or end 2610. It starts with a SNC or a LC and then a LC or a SNC. This is performed this there is no more elements. Protecting subroute components are marked with additional information to indicate which type of trail they belong to (in a working trail or in a protecting trail). Once all the elements have been processed, the extms and the borders of the trail are marked (2612).

In the second type the subroute entities occupation consists of treating the ordered list of entities and generating actions to associate the entity with the created trail. The sequence of components must be a port, then a link connection, and then other port. The last component must be a port.

In the third type, the subroute entities occupation consists of treating the ordered list of entities, building actions to associate the entity with the trail and checking the continuity between entities at the equipment level. If the route uses ports then the first and last component must be ports. Otherwise, if the route uses termination point then the first and last must be termination points.

This stage sets up the trail ends, they may be termination points or ports, and it also sets up the border termination points. These points mark the management limits.

The components out of them are not managed or are located out of the network.

After the trail is set in a layer, it is necessary to build the structure to support the client layer 2614 ('Generate Infrastructure' box):

If the route uses termination points then the termination trail points must be structured. It generates actions to build the link connections according with the layer restrictions and the client/server relations with other layers. Besides it generates the actions to build client termination points. These points will be clients of the termination trail point, and the ends of the link connection.

If the route uses ports then it generates actions to build link connections according to the layer restrictions and the client/server relations with other layers. If there is an associated port in the equipments ends then they will be the ends of the link connection. If the route has a protecting subroute then this stage generates actions to build protecting units and groups 2615. The administrative entities are built according to the protecting type: SNCP or MSP. These actions are based on the trail ends, the protecting ends, and the protecting subroute entities.

DATA OUTPUT

It composes data output to get a complete set of actions to be performed in order to build and end-to-end route.

Although the present invention has been described with reference to specific embodiments, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention as defined by the following claims.

Claims

C L A I M S

1 . A method to build end-to-end routes from a known origin, a known destination and intermediate network components which must be part of the end-to- end route, over a transmission multi-vendor network and over different networks, from a provided minimum and disordered set of network administrative information called Initial Route which comprises network physical and logical entities, which must be part of the end-to-end route, and rules and restrictions of the different network layers;

the method comprising the following stages:

- analyzing said Initial Route by sorting out the list of network resources provided into a logical sequentially order based on its ubication;

- building a set of continuous route segments which include working and protecting route components, deciding the appropriate type of route protection and assigning the appropriate transmission media to each of said route segments;

- generating all necessary trails and logical entities to carry the signal through the different network layers according to rules in the different ports, restrictions regarding the different network layers which support said trails, wherein each trail is comprised by a set of subroutes;

- from these trails performing the actions to build the structure which supports the end-to-end route by generating or occupying, if the resources are already available, the necessary logical entities and route components as defined by the trails, wherein these entities and network components are physical: ports and transmission media, and logical: trails, link connections, subnetwork connections, termination points, protecting groups and protecting units.

2. A method according to claim 1 , wherein each route component is characterized by the different type of route which it belongs to, working route, which is assigned to transfer the signal, or protecting route, which is assigned to assure the availability when a fail or degradation occurs by switching the signal and transferring it across the protecting components of the network.

3. A method according to claim 2, where if there is any route component assigned to a protecting route, then it is determined the type of protection: SubNetwork Connection Protection, SNCP, or Multiplex Section Protection, MSP.

4. A method according to any of the previous claims, where a sorted ubication list is obtained sorting the initial Route, where in said initial route each ubication is analysed to process first the link connections which have an end in the analyzed ubication and another end in a different one, then ports in the ubication and finally the link connection that have both ends in the same ubication;

5. A method according to claim 4 where the link connections which have and end in other ubication are processed according the following steps:

- processing the route to the Connection Termination Point, CTP (1404), searching a sequence of continuous link connections, being the end CTP of the next link connection on the same equipment than the start CTP of the previous link connection, and the A port where route segment starts;

- then processing the route from the CTP (1405), searching a sequence of continuous link connections, being the start CTP of the next link connection on the same equipment than the end CTP of the previous link connection, and the Z port where route segment ends;

- finally joining both routes (1406), constituting a continuous segment between A port and Z port, which is added to the set of route segments.

6. A method according to claim 4 which determines sequences of continuous link connections from the ports not treated in the analyzed ubication and link connections with both ends in the analysed ubication not yet treated and it processes the link connections with the same rules as in claim 4.

7. A method according to any previous claim where the transmission media is assigned to the correct route segment generated previously, wherein this process is repeated until all transmission media is treated.

8. A method according to claim 1 where route components are included in the specific trail depending on their corresponding network layer, wherein each trail comprises a set of subroutes with a type, and each subroute is comprised by a port set, a termination point set, a link connection set and a transmission media set.

9. A method according to claim 1 which it adds a new working subroute and processes the source and target port in the route, assigning source port as the one of the first working segment and target port as the one of the last working segment, allowing the trail to end by including a Termination Connection Point where said trail ends, if it is a partitioned port, and establishing the trail as initial trail.

10 A method according to claim 9 where each segment is treated in order to add route components to the subroute, beginning from the source port (2204) of each one, wherein the method depends of whether said port can be partitioned or not (2205), being an unpartitioned port the one performing termination connection and trail termination functions and supporting only one network layer, where

- if source port is unpartitioned, adding said port to port set (2214), the other unpartitioned ports of that segment (2224), the transmission media of that segment (2225) and the link connections that end in unpartitioned ports of that segment (2216 - 2217) to the subroute;

- If source port can be partitioned (2205) or a partitioned port is found in a segment which source port is unpartitioned (2221 ), adding said port to the subroute if it belongs to the circuit layer and it is a border port of the trail (2223, 2207), and continuing with the processing of link connections, if exists a link connection that ends in the same equipment of that port (2208), otherwise continuing with the processing of said port (2212).

1 1 . A method according to claim 10 where if the source port can be partitioned, the link connections found are analyzed and processed in order to generate the necessary logical entities to transfer signal across them, wherein from current trail and port, comprise the following steps:

- if first link connection cannot be assigned to current trail (2305), including as many trails as are necessary (2306-2313) until the link connections can be assigned to the current trail and port (2314), adding each trail to collection trail (2308), assigning current trail as the last trail included (2309), and adding termination point TTP of each trail to its working subroute (2313);

adding each link connection (2316) included in the working route of the segment (2318, 2319) to working subroute of the current trail; adding subnetwork connections between the termination point TTP of trail in the current port and termination point of the first link connection in the route (2315); between termination points of each link connection and termination point of next link connection in the same equipment (2321 ); and between termination point of the last link connection (2323) and a termination point (TTP) of trail in next port in ports collection (2322) to current trail working subroute.

- if the segment includes a protecting route (2327), then adding a new protecting subroute (2328) and including each link connection assigned to protection route of the segment (2329), getting termination point (TCP) of each link connection added to protecting subroute (2330), obtaining next link connection in protecting route of segment (2331 ), and, if a link connection is obtained, adding a subnetwork connection between termination connection point of last added link connection and termination connection point of the obtained link connection which are located in the same equipment (2333, 2334);

- if current trail has been generated in first step, processing it to terminate the working subroute (2326).

12. A method according to claim 10 where the ports found and not connected to a link connection are analyzed and processed in order to generate the necessary logical entities which from current trail and port the processing comprise the following steps: - if current trail is not in the physical layer (2503) then building as many trails as layers can end in the current port (2504-2509) until the trail is in the physical layer (2503), adding each trail to collection trail, and adding termination point (TTP) of each trail to its working subroute (251 1 );

- including physical layer TTP in current port (251 1 ), the transmission media (2517) and physical layer TTP in next port in ports collection to working subroute (2516);

If physical layer trail has been generated in the first step, processing it to terminate working subroute (2519).

13. A method according to claim 1 1 and 12 where the operations to process the trails in order to terminate the route comprise the following steps:

- generating the final route assigned to the last trail in the collection

- generating a new action to build a trail and including it into actions set; - deleting the trail from new trails collection (2402) and getting the next trail in the collection (2404);

If there is not a trail (2403), then establishing initial trail as current trail (2413);

- adding the link connection supported by the last server trail to the current trail subroute (2406) and also adding a new subnetwork connection between the last termination point included in the subroute and the termination point of the link connection in the same equipment (2405); If the current trail can end in the last treated port (2407), then adding a new subnetwork connection between the last termination point in the subroute and the termination point of the trail in the port (from 2408 to

2410); and if the current trail is not the initial trail (2412) then repeating these operations by returning to the beginning of this processing (2401 ). In other case, adding the other termination point of the link connection to the current trail subroute (2414);

14. A method according to claim 1 where occupation of logical entities and network resources is characterized by the type of route and comprises the actions to associate the entity with the generated trail.

15. A method according to claim 14, where when there is a continuous route which uses termination points, the sequence of elements occupation must be a subnetwork connection (2605), then a link connection (2606) and other subnetwork connection (2607), where the last element must be always a subnetwork connection.

16. A method according to claim 14, where when there is a continuous route which uses ports, the sequences of elements occupation must be a port, then a link connection, and then other port, where the last element is always a port.

17. A method according to claim 14 where when there is a discontinuous route which it uses termination points the first and last element in occupation sequence are termination points; otherwise if the route uses ports, then the first and last element of the occupation sequence are ports.

18. A method according to claim 1 where after a trail is set in a layer; it is built the structure to support the client layer which it comprises:

If the route uses termination points then the termination trail points must be structured, generating actions to build the link connections according with the layer restrictions and the client/server relations with other layers;

- generating the actions to build client termination points, where these points will be clients of the termination trail point, and the ends of the link connection;

- If the route uses ports then generating actions to build link connections according to the layer restrictions and the client/server relations with other layers where if there is an associated port in the equipments ends, then they will be the ends of the link connection.

19. A system comprising means adapted to perform the method according to any preceding claim.

20. A computer program comprising computer program code means adapted to perform the method according to any claims from 1 to 18 when said program is run on a computer, a digital signal processor, a field-programmable gate array, an application-specific integrated circuit, a micro-processor, a micro-controller, or any other form of programmable hardware.