Abstract:
A method and human-machine interface for Virtual Local Area Network (VLAN) provisioning in bridged networking environments are provided. The method includes steps of provisioning VLAN support for each customer VLAN on every data transport trunk and by extension of every data trunk port in the associated data transport network. The human-machine interface enables an operator to expediently effect VLAN provisioning abstracting the intricacies of the data transport network over which VLAN services are provisioned. Advantages are derived from VLAN provisioning independent of an underlying in-use active spanning-tree topology. In particular customer VLANs are provisioned over spanning-tree stand-by designated data transport trunk links and therefore pre-provisioned in the case of spanning-tree re-configuration. Operator VLAN provisioning tasks are lessened via provisions for the selection of all data transport trunk links/ports in the data transport network.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to network management and service provisioning, and in particular to reducing overheads in provisioning virtual local area networks services over an infrastructure of bridged networks.  
         TECHNICAL OVERVIEW  
         [0002]    A Local Area Network (LAN) includes a group of data network nodes and various data transport equipment that share, a common communications medium and other data transport resources. Usually, LANs provide data transport services for homes, small businesses and departments within large enterprises.  
           [0003]    Most LANs are confined to a single building or group of adjacent buildings. However legacy LANs technology is inadequate in supporting: an ever increasing telecommuting work force, remote office connectivity, decentralized government services, etc. because of a limited reach.  
           [0004]    Customer-owned disparate LANs can be interconnected over large distances via dedicated links such as wire and wireless links. Another alternative to disparate LAN interconnectivity can be achieved by connecting each LAN segment to a carrier data transport network. The separate LAN segments are said to be bridged. The Internet is one of the largest public carrier networks. A group of interconnected LANs is referred to as a Wide Area Network (WAN). Nevertheless, customers incur a large overhead in provisioning, managing and maintaining disparate LANs.  
           [0005]    Data carrier networks can be said to provide connection-less and connection-oriented data transport services. The Internet is the largest connection-less data transport network typically employing the Internet Protocol to convey packets. Selected portions of the Internet, provisioned by certain service providers, offer connection-oriented data transport typically employing exemplary technologies such as Asynchronous Transfer Mode (ATM) and Multi-Protocol Label Switching (MPLS). Various other data transport technologies exist of which connection-less technologies have enjoyed a long term utilization and represent a large portion of the installed infrastructure. Connection-less technologies are prevalent in LAN environments and will therefore represent the focus of the present description without limiting the application of the described concepts thereto.  
           [0006]    Connection-less data transport technologies regard data transport media as broadcast media via which the participating data network nodes exchange data packets. While broadcasting data is conducive to efficient data interchange within a LAN, in bridging geographically displaced LANs via carrier data networks, the broadcast-type data transport leads to data transport inefficiencies in the service provider&#39;s data transport network and perhaps to potential disclosure of closely-held information. The connection-less broadcast-type data transport in carrier networks does however benefit from redundant data transport, the broadcast-type data transport in effect routing data transport around failed data transport equipment by design.  
           [0007]    Recent developments in the data communications field have brought about a Virtual LAN (VLAN) paradigm enabling the LAN to be extended into homes, remote office sites, geographically displaced government offices, etc. over existing installed infrastructure. VLAN technology enables logical grouping of data network nodes and related data transport infrastructure to extend LANs beyond the restrictions imposed by the underlying infrastructure. Data network nodes associated with the same VLAN behave as if participating in the same LAN, benefiting from the broadcast-type information exchange therebetween. As portions of the VLAN are typically provisioned over carrier networks, VLAN associated routing of data packets within carrier networks can be engineered to follow definite paths while still benefiting from redundant connectivity. The logical associativity defining the VLAN provides data traffic differentiation which enables encryption based protection of closely-held information. VLAN technologies enable routing of data packets based on the VLAN associativity thereof.  
           [0008]    The logical grouping of data network nodes reduces the provisioning, the management, and the reconfiguration of data transport infrastructure for the customer by providing logical network design solutions with minimal changes to physical installed infrastructure. Data network nodes in each LAN segment of the VLAN are unaware as to whether they are connected to a single LAN segment or multiple bridged LAN segments.  
           [0009]    A multitude of independent carriers cooperate in provisioning carrier WANs of the likes of the Internet. Although, in theory, data transport network infrastructure may be installed such that only one data transport path may exist between any two data network nodes; the amount of network configuration information that must be considered for such a data network design would be overwhelming and, as it was mentioned above, undesirable as a level of data transport redundancy is desirable for sustained data transport.  
           [0010]    For a connection-less data transport network to function optimally, only one active data transport path should exist between any two data transport nodes. Multiple active paths between data network nodes cause loops in the associated network. If a loop exists in the network topology, the potential exists for duplication of data packets. When loops occur, a packet switching node deems at least one destination data network node to be reachable via multiple data ports associated with the data switching node. Under such conditions, forwarding algorithms employed at data switching nodes are designed to replicate data packets for transmission over the multiple data ports. It is desirable to limit such conditions to purposely configured instances thereof.  
           [0011]    Developments in data packet routing include the adoption of a spanning-tree protocol and associated spanning-tree determination algorithms. The spanning-tree protocol is a link layer management protocol that prevents the establishment of undesirable data transport loops in data transport paths while providing support for data transport redundancy.  
           [0012]    To provide path redundancy, the spanning-tree protocol defines a tree of in-use interconnecting data transport links that spans all data switching nodes in the associated data transport network. The spanning-tree protocol configures certain redundant data transport links into a standby state. If a data transport network segment previously under the influence of the spanning-tree protocol becomes unreachable, or if spanning-tree protocol configuration parameters change, the spanning-tree algorithm reconfigures the spanning-tree topology and re-establishes data transport to the unreachable data transport network segment by activating for use selected standby data transport links.  
           [0013]    When the spanning-tree protocol is used in the carrier data transport network, the operation of the spanning-tree protocol is transparent to customer data network nodes and perhaps even to customer LANs. Dependent on a particular implementation of and the services supported over a carrier data transport network, multiple in-use spanning-trees may be defined and coexist. For example, a spanning-tree of in-use data transport links may be defined for high data throughput utilizing high bandwidth links, while another spanning-tree of in-use data transport links may be defined for low data transport latency utilizing the fewest number of data transport links.  
         BACKGROUND OF THE INVENTION  
         [0014]    Connectivity determining spanning-tree algorithms may be run centrally via Network Management Systems (NMS) by analysts. To do so the analyst and the associated NMS must posses a large amount of information regarding data transport infrastructure in a realm of management of the NMS. Central spanning-tree determination benefits from an availability of the resulting spanning-tree for the analysts perusal in providing support for manual VLAN provisioning. Such solutions however tend to be reactive as data transport equipment failure instances require the analyst&#39;s attention at least in re-provisioning VLANs to re-establish VLAN connectivity over reconfigured spanning-trees.  
           [0015]    In order to reduce network management and service provisioning overheads, the spanning-tree protocol may be implemented in a decentralized fashion with each data network node and data switching nodes running spanning-tree determination algorithms. A collective exchange of information therebetween provides the necessary information to determine and establish spanning-tree connectivity. While such a solution reduces the need for analyst intervention in re-establishing data transport connectivity subsequent to data transport infrastructure failures, the active in-use spanning-tree exists typically only as operational parameter configurations within individual data transport equipment and is unavailable to the analyst and the NMS for re-provisioning VLAN connectivity.  
           [0016]    While co-pending commonly assigned Unites States Patent Application entitled “Virtual Local Area Network Auto-Discovery Methods” filed on even date, bearing attorney reference number 13597-US; describes methods of deriving VLAN configuration information from participating data network nodes, the described methods do not delve into VLAN provisioning. A considerable operational overhead is still incurred in manual VLAN provisioning.  
           [0017]    Referring to FIG. 1, prior art VLAN provisioning is performed manually by configuring individual data transport and switching equipment to provision trunk ports (TP)  102  and access ports (AP)  104  of manually selected data switching nodes  106  in a service provider (carrier) network  100 . Such a prior art manual VLAN provisioning solution is provided by CISCO Systems&#39; VLAN Director software version 2.1.  
           [0018]    The access ports  104  are connected via access links  130  to the customer LANs  110  and the trunk ports  102  are connected to the data transport trunks  108  between the data switching nodes  106 .  
           [0019]    The use of the spanning-tree protocol avoids the creation of loops in the data transport network  100  by putting certain data transport trunks  108  in a stand-by state thereby preventing the replication of data packets  120 / 122  thereto as would otherwise result. Stand-by data transport trunks  108  are shown by dashing in the FIG. 1. In-use data transport trunks  108  are shown solid. A similar depiction is used with respect to the corresponding ports  102 . Prior art VLAN provisioning methods typically call only for the trunk ports  102  and routers  106  associated with in-use data transport trunks  108  to be included in VLAN provisioning.  
           [0020]    In accordance with the example shown in FIG. 1, the configuration of VLAN 2  includes three customer LAN segments  110  at respective sites  1 ,  3 , and  5 ; the LAN segments  110  are connected to respective routers  106 -R 1 ,  106 -R 3 , and  106 -R 2  of a service provider&#39;s data transport network  100 . Packets  120  of VLAN 2  are routed over the shared service provider&#39;s carrier network  100  in accordance with the spanning-tree protocol, which has designated: router  106 -R 5  as a spanning-tree root node, data transport trunks  108 -dashed on stand-by to prevent the formation of logical loops in the data transport network  100 , and data transport trunks  108 -solid in-use. For example, VLAN 2  is provisioned only on ports  102 -P 1  and  102 -P 2  on each of routers  106 -R 1 ,  106 -R 2 , and  106 -R 3  and on ports  102 -P 1 ,  102 -P 2 , and  102 -P 3  on router  106 -R 5 .  
           [0021]    Data packets  120 / 122  are routed through the carrier data transport network  100  over the loop-free spanning-tree of data transport trunks  108 -solid using Open Systems Interconnect (OSI) Layer-2, typically Media Access Control ADDResses (MAC ADDRs) conveyed in data packet  120  headers when the trunk ports  102  are provisioned (associated) with only one VLAN. In the case where a trunk port  102  is provisioned to support more than one VLAN, a VLAN identifier is added in the packet headers ( 122 ) in accordance with the IEEE 802.1Q protocol incorporated herein by reference. The VLAN identifier is used to route data packets  122  through the network  100  and the VLAN identifier is removed from packet headers when no longer needed. Ports  102 -P 2  of routers  106 -R 2  and  106 -R 5  are provisioned for both VLAN 2  and VLAN 3 . VLAN data packets  122  thereby necessitate the use of the VLAN identifier to differentiate data traffic.  
           [0022]    As routing examples, a packet  120  is shown to be routed from data network node  112 -A to data network node  112 -B using only the MAC address of node  112 -B; another packet  122  is shown to be routed from node  112 -C to node  112 -D using the VLAN identifier for VLAN 3  between routers  106 -R 2  and  106 -R 5 , and using the MAC address for node  112 -D over the rest of the data transport path.  
           [0023]    In the event of a service-affecting fault, the spanning-tree protocol will recalculate the spanning-tree and re-assign data transport trunks  108  in-use.  
           [0024]    The problem with the prior art solutions resented above lies in determining which data transport trunks  108  are chosen for use by the spanning-tree protocol. Such determination can be difficult and time-consuming, thereby making provisioning of VLANs likewise difficult and time-consuming. This is especially the case for large and complex data transport networks  100 . The redefinition of the spanning-tree requires corresponding manual re-provisioning of the VLANs. Such manual provisioning is error prone.  
           [0025]    Another development in the field which addresses VLAN provisioning methods is exemplified by CISCO&#39;s VLAN Trunk Protocol (VTP). The VLAN trunk protocol is a CISCO Systems proprietary solution to propagating manually configured VLAN information between adjacent VTP aware network elements. The propagation of VTP information is implemented as differentiated data traffic over VLAN  1  which means that VLAN support must be apriori activated for each VTP aware network element. To date only selected CISCO Catalyst products support the VTP protocol. The suitability for using the VTP protocol is dependent on: the definition of VTP domains of which other vendor equipment would be unaware, the establishment of VTP server/client relationships between VTP aware (CISCO only) network elements, memory for storage of VTP related information at each participating VTP aware network element, the ability to parse VTP specific frames, the ability to respond to a particular reserved broadcast address in exchanging VTP related information, etc. Although some benefit may be derived from the use of the VTP protocol over a CISCO only network equipment infrastructure, numerous shortcomings of the present definition of the VTP protocol call for the reduction of the extent of provisioned VLANs, which runs counter to the need to extent VLANs beyond the restrictions imposed by the physical network infrastructure. Various workarounds call for quick manual re-provisioning of VLAN support as the only reactive solution.  
           [0026]    There therefore is a need to reduce operational overheads in provisioning VLAN support in data transport networks and lessen the reliance of provisioning on trained personnel.  
         SUMMARY OF THE INVENTION  
         [0027]    In accordance with an aspect of the invention, a method of provisioning a Virtual Local Area Network (VLAN) is provided. The steps include: obtaining at least one VLAN Identifier, selecting a plurality of VLAN trunks, and associating the VLAN ID with each one of the plurality of VLAN trunks. The selection and association of the VLAN ID with each one of the plurality of VLAN trunks is to be undertaken irrespective of an in-use and a stand-by designation of each one of the plurality of VLAN trunks.  
           [0028]    In accordance with another aspect of the invention, a method of provisioning a VLAN trunk is provided. The method includes steps of: obtaining a plurality of VLAN IDs associated with a corresponding plurality of provisioned VLANs, and associating the plurality of VLAN IDs with the VLAN trunk. The association of the plurality of VLAN IDs with the VLAN trunk is to be undertaken irrespective of a one of an in-use and a stand-by designation of the VLAN trunk.  
           [0029]    In accordance with a further aspect of the invention, a method of provisioning a VLAN trunk port is provided. The method includes steps of: obtaining a plurality of VLAN IDs associated with a corresponding plurality of provisioned VLANs; and associating the plurality of VLAN IDs with the VLAN trunk port. The association of the plurality of VLAN IDs with the VLAN trunk port is to be undertaken irrespective of a one of an in-use and a stand-by designation of the VLAN trunk port.  
           [0030]    In accordance with a further aspect of the invention, a VLAN provisioning human-machine interface is provided. A VLAN ID selector is used for selecting a plurality of VLAN IDs. A VLAN trunk selector is used for selecting a plurality of VLAN trunks. And, an activator is used for committing associations between the plurality of VLAN IDs and the plurality of VLAN trunks. The associations between the plurality of VLAN IDs and the plurality of VLAN trunks are to be made irrespective of one of an in-use and a stand-by designation of each one of the plurality of VLAN trunks.  
           [0031]    In accordance with yet another aspect of the invention, a network management system for effecting VLAN provisioning in a managed communications network is provided.  
           [0032]    The exemplary solution described provides enhanced VLAN provisioning, which saves an operator&#39;s time, thereby reducing a service provider&#39;s operating costs. The described solution benefits from being implemented on a Network Management System (NMS) because VLAN provisioning methods presented do not require selection of routers and trunk ports but rather involves provisioning VLAN support on all trunk links in an associated data transport network.  
           [0033]    The solution provided increases the reliability, availability and serviceability of provisioned VLANs of pre-provisioning thereof on all trunk links including spanning-tree protocol stand-by designated trunk links. The stand-by data transport trunk links are ready for use should the spanning-tree be redefined, thereby reducing the time required to bring the VLAN into service on the newly defined spanning-trees.  
           [0034]    Because the management is done through the human-machine interface on an NMS, the presented VLAN provisioning methods are much more efficient than error prone legacy manual command entry approaches performed via a console on a per router/per trunk port basis. The NMS has the advantages of being able to display/configure/modify the provisioned VLANs and show any inconsistencies or misconfigurations thereof. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0035]    The features and advantages of the invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached diagrams wherein:  
         [0036]    [0036]FIG. 1 is a schematic diagram showing configured interconnected data transport elements providing VLAN support in accordance with prior art VLAN provisioning solutions;  
         [0037]    [0037]FIG. 2 is a schematic diagram showing, in accordance with an exemplary embodiment of the invention, configured interconnected data transport elements providing VLAN support;  
         [0038]    [0038]FIG. 3 is a schematic diagram showing, in accordance with the exemplary embodiment of the invention, a result of a data transport equipment failure of configured interconnected data transport elements providing VLAN support;  
         [0039]    [0039]FIG. 4 is a schematic flow diagram showing VLAN provisioning process steps used, in accordance with the exemplary embodiment of the invention; and  
         [0040]    [0040]FIG. 5 is a schematic diagram showing, in accordance with the exemplary embodiment of the invention, generic elements of a human-machine interface used in VLAN provisioning.  
     
    
       [0041]    It will be noted that in the attached diagrams like features bear similar labels.  
       DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0042]    [0042]FIG. 2 is a schematic diagram showing configured interconnected data transport elements providing VLAN support.  
         [0043]    In accordance with an exemplary embodiment of the invention, each VLAN is provisioned on all trunk links  208  in the service provider&#39;s data transport network  100 —including stand-by designated data transport trunk links  208 -dashed, providing for VLAN pre-provisioning at improved operational efficiencies. This technique eliminates the need to determine specific in-use data transport trunk links  108  and specific in-use trunk ports  102  on specific routers  106  participating in the active in-use spanning-tree topology.  
         [0044]    The service provider&#39;s data transport network  100  typically carries data traffic associated with more than one VLAN. IEEE 802.1Q VLAN identifiers must be included in VLAN associated packet headers ( 222 ) to provide traffic differentiation. The packets  222  are routed through the carrier&#39;s data transport network  100  using the VLAN identifier in accordance with the IEEE 802.1Q protocol specification.  
         [0045]    As the spanning-tree protocol prevents the formation of logical data transport loops, VLAN provisioning over stand-by designated data transport trunk links  208 -dashed is not a concern. In fact, pre-provisioning data transport trunk links  208 -dashed for all provisioned VLANs has the advantage of making the data transport trunk links  208 -dashed ready to carry VLAN traffic should the spanning-tree reconfigure.  
         [0046]    [0046]FIG. 3 shows the response of the data transport network  100  to a service-affecting failure  300  experienced by the data transport trunk link  208  between routers  106 -R 2  and  106 -R 5 . In accordance with the spanning-tree protocol, as a response to the fault  300 , spanning-tree algorithms executing (collectively) on routers  106  recalculate the spanning-tree.  
         [0047]    In accordance with the exemplary result shown, the spanning-tree recalculation results in previously unused data transport trunk link  208  between routers  106 -R 2  and  106 -R 1  participating in the active topology, and data transport trunk link  208  experiencing the failure  300  being taken out of the tree. Since in accordance with the exemplary embodiment of the invention, the newly activated for use data transport trunk link  208  has already been provisioned for VLAN 2  and VLAN 3 , it is immediately available for use by the provisioned VLANs. For example, a packet  222  destined for node  112 -D is subsequently routed from the router  106 -R 2  to the router  106 -R 4  via the routers  106 -R 1  and  106 -R 5 .  
         [0048]    [0048]FIG. 4 is a flow diagram showing VLAN provisioning process steps used, in accordance with the exemplary embodiment of the invention.  
         [0049]    The VLAN provisioning process  400  enables an operator to create new VLAN customers, create unique VLAN identifiers, add new trunk links  208 , etc. in the carrier&#39;s data transport network  100 , and interlink selective customer sites to participate in a particular provisioned VLAN. The above VLAN provisioning functions may be performed independently. The presented VLAN provisioning process  400  further incorporates an exemplary logical progression of steps without limiting the invention thereto.  
         [0050]    Depending on a particular VLAN provisioning task faced by an operator, a determination  402  is made as to whether VLAN provisioning is to be effected for a new customer. If a new customer is to be supported, the process  400  may include a step of defining a new customer profile  404 . At least one unique VLAN identifier is generated  406  for the new customer.  
         [0051]    In generating the unique VLAN identifier the process  400  either chooses a next unused VLAN identifier, or a previously surrendered and unused VLAN identifier. The selected unique VLAN identifier is subsequently blocked from reuse  408 , typically by being stored in a roster of in-use VLAN identifiers. In accordance with the IEEE 802.1Q protocol specification, 12bits are used in packet headers to specify VLAN identifiers. The IEEE 802.1Q protocol specification also reserves selected VLAN identifiers for protocol related functions. The reserved VLAN identifiers may also be included in the roster of in-use VLAN identifiers to simplify VLAN provisioning. The reserved VLAN identifiers cannot be surrendered for subsequent reuse.  
         [0052]    In accordance with the exemplary embodiment of the invention, in step  410  of the VLAN provisioning process  400 , all defined data transport trunk links  208  in the carrier&#39;s data transport network  100  are selected and associated  414  with the VLAN identifier. The definition of data transport trunk links  208  represents a carrier network provisioning task described elsewhere. Note that the selection of all data transport trunk links  208  in the data transport network  100  is done regardless of the in-use/stand-by designation thereof resulting from the execution of spanning-tree algorithm(s).  
         [0053]    The definition of data transport trunk links  208  includes the specification of origination and termination trunk ports  202 . A network management database (NMS DB)  250  holds data transport trunk link definitions. The association  414  of the VLAN identifier with all trunk links is typically implemented via VLAN identifier associations with the corresponding trunk ports  202 . All of the corresponding trunk ports  202  are determined  426 , and the VLAN identifier is associated  428  therewith. VLAN provisioning database records held by each router  106  in the carrier&#39;s data transport network  100  show (see FIG. 2) the VLAN identifiers associated with each trunk port  202 .  
         [0054]    To complete VLAN provisioning, the VLAN identifier needs to be associated with access ports  104  corresponding to each customer site ( 110 ). Access ports  104  are selected  432  corresponding to each customer site for which the selected VLAN is to be provisioned. The VLAN identifier is associated  434  with the selected access ports  104 .  
         [0055]    While operating a data transport network  100 , typically new data transport trunk links  208  may be added. In accordance with the exemplary embodiment of the invention, if a new data transport trunk link is added  442  to the service provider&#39;s data transport network  100 , all provisioned VLANs should be associated with the new data transport trunk link  208 . Therefore, the VLAN provisioning process  400  selects all provisioned VLANs in step  444  and (subject to add/removals  446 ) associates  448  all (selected) provisioned VLANs to the new data transport trunk link  208 . In implementing step  448 , the provisioning process  400  performs steps  426  and  428  as described herein above.  
         [0056]    Provisioned VLAN support for a selected  452  existing customer, may be modified by: provisioning additional VLANs for existing customers and/or modifying the group of LAN segments associated with provisioned VLANs.  
         [0057]    In the case of provisioning additional VLANs  454  for a selected  452  customer the VLAN provisioning process  400  is resumed from step  406 .  
         [0058]    In modifying the group of LAN segments associated with provisioned customer VLANs, a valid VLAN identifier is selected  462  and the VLAN provisioning process  400  resumes from step  432 .  
         [0059]    While operating a data transport network  100 , typically new customer LAN segments  110  may be added. From the perspective of the service provider&#39;s network  100 , the addition ( 472 ) of a new customer LAN segment  110  corresponds to bringing a corresponding access port  104  into service. To provision VLAN services to the newly added customer LAN segment  110 , at least one VLAN identifier is selected  474  and the VLAN provisioning process  400  resumes from step  434 .  
         [0060]    It is understood that the methods of VLAN provisioning described herein are not limited to VLAN provisioning on trunk links  208  and have been presented as such to simplify the presentation of the relevant concepts. In fact each router  106  is unaware of trunk links  208  and only aware of corresponding trunk ports  202 . Moreover in provisioning a VLAN on a trunk link  208 , corresponding trunk ports  202  on separate routers  106  at each end of the trunk link  208  must be configured. Dependent on the actual data transport technology used to physically convey data over trunk links  208  more than two trunk ports  202  may have to be configured for each trunk link  208 . For example each trunk link  208 : consists of two separate unidirectional data transport links (four ports  202 ), use of inverse multiplexing data transport techniques (double the number of physical links), etc. Restated another way, in accordance with the invention, each VLAN is provisioned on all data transport ports  202  in the data transport network  100 . This is what actually takes place as described with reference to VLAN provisioning steps  426  and  428 . In the interest of reducing operational overheads this level of detail is purposely abstracted in providing the exemplary VLAN provisioning solution. The NMS database  250  maintains associations between data transport equipment in the data transport network  100  defining corresponding trunk links  208 .  
         [0061]    The VLAN provisioning process  400  is a service provider performed service which ensures the uniqueness of the VLAN identifiers used in the carrier&#39;s data transport network  100 . The VLAN provisioning process reduces VLAN provisioning overheads.  
         [0062]    Inevitably edge managed data network elements in the managed data transport network  100  are used to provide connectivity with adjacent data transport networks managed by peer service providers. Therefore VLAN trunks  208  bridging two managed domains exist. For such VLAN trunks, the VLAN provisioning methods apply at least to the proximal managed corresponding VLAN trunk ports.  
         [0063]    Varying VLAN service offerings blur the requirement for inclusion of VLAN access port  104  configuration into VLAN provisioning. VLAN service offering exist in which customer premise equipment providing VLAN support are provided by the VLAN service provider. Therefore the VLAN service provider may at least managed the backbone side of the customer premise equipment providing the VLAN support. In accordance with such a service offering, a VLAN trunk  208  exists between the service provider&#39;s carrier network  100  and the particular customer site  110  with both VLAN trunk ports associated therewith falling in the service provider&#39;s management domain. VLAN access port configuration on the private side of the provided customer premise equipment falls under the customer&#39;s realm of management.  
         [0064]    When implemented on a Network Management System (NMS)  240 , see FIG. 2, the VLAN provisioning process  400  may be operable via a graphical user interface having widgets such as selection boxes, buttons, specifier fields, etc.  
         [0065]    [0065]FIG. 5 is a schematic diagram showing, in accordance with the exemplary embodiment of the invention, generic interactive elements of a human-machine interface used in VLAN provisioning. It is understood that combinations of the presented elements may be used to generate a multitude of graphical user interface panels for a more intuitive and/or more standardized human-machine interface. It is further understood that the exemplary human-machine interface  500  presented herein may be further simplified by overloading the function of the various interactive elements to perform context aware actions.  
         [0066]    The definition (step  404 ) of the customer profile may be implemented via compound selection box  502  for specifying unique customer identifiers such as customer names.  
         [0067]    Subsequent to filing the customer specification field  502 , an “Activate Customer” button  504  may be pressed to create a context in which subsequent VLAN provisioning actions may be performed. The uniqueness of the customer name may be ensured by comparing the specified customer identifier provided with a list tracking active customer identifiers. The list of active customer identifiers may be available for browsing and display via the compound selection box  502 .  
         [0068]    If the specified customer identifier already exists, then the specified customer profile is selected and made the active profile for subsequent actions (implementing the customer selection functionality of VLAN provisioning step  452 ), otherwise a new customer profile is created and activated for subsequent actions (implementing the functionality of VLAN provisioning step  404 ).  
         [0069]    A “De-activate Customer (Profile)” button  506  may also be provided. De-activating a customer profile may only free VLAN identifiers associated with the customer. The customer profile may be retained for other purposes.  
         [0070]    Activating a customer profile by pressing the button  504  further updates a VLAN selection list  510  with provisioned VLANs for the active customer profile. If the customer profile has just been defined ( 404 ), then the list  510  of VLANs provisioned for the customer is initially empty. A “Generate New Unique VLAN” identifier button  512  is provided for implementing functionality of steps  454  and  406  of the VLAN provisioning process.  
         [0071]    In generating  406  a new unique VLAN identifier subsequent to the creation of a new customer profile, the VLAN list  510  will have one entry specifying: a new unique VLAN identifier, the corresponding (active) customer identifier, and a VLAN provisioning status—“New” in this case.  
         [0072]    An “Activate Selected VLAN” button  514  and a “Delete Selected VLAN” button  516  may also be provided. In pressing the Delete Selected VLAN button  516 , all corresponding VLAN identifier associations to data transport trunk links  208  and access ports  104  are removed. The corresponding VLAN status will display “Pending” while the associations are removed. Subsequent to the removal of VLAN associations, the corresponding VLAN identifier is released and made available for subsequent re-use.  
         [0073]    Typically network management and service provisioning can and is performed in parallel via a multitude of NMS&#39;  240 . Therefore, so can VLAN provisioning be performed in parallel. In accordance with such an implementation, the VLAN identifier roster  252  and customer list  254  are shared between all participating NMS&#39;  240 . A “Refresh/Show All VLANs” button  518  is provided to refresh the VLAN list  510 , perhaps also refreshing the VLAN provisioning status for all VLANs. Pressing the Refresh/Show All VLANs button  518  may have a context sensitive response. If a customer is active, then the VLAN list  510  will refresh VLANs associations with the active customer. If no customer is active, then the VLAN list  510  will show all VLANs irrespective of customer association. The usefulness of the later capability will further become more apparent from the description herein below making reference to provisioning new data transport trunk links  208  and to provisioning of new access ports  104 .  
         [0074]    Activating a selected VLAN, the NMS  240  presents the operator with a list  520  of all of the data transport trunk links  208  on which the VLAN is provisioned. In the case of a newly created VLAN, the list of trunk links  520  would be empty.  
         [0075]    As mentioned above, data transport trunk links  208  are provisioned via processes described elsewhere and may happen in parallel with VLAN provisioning. A “Refresh/Show all Trunk Links” button  522  is provided to display all provisioned data transport trunk links  208  in the data transport network  100 . Since data transport trunk links  208  may be associated with more than one VLAN, the VLAN provisioning status displayed in the trunk link list  520  may only have meaning in the context of a then currently active VLAN. An exemption is a newly provisioned data transport trunk link  208  which does not yet have VLAN associations and whose VLAN provisioning status is “New”.  
         [0076]    In accordance with the exemplary embodiment of the invention, a single click of an “Add All Trunk Links” button  524  is sufficient to initiate VLAN provisioning on all data transport trunk links  208  in the service provider&#39;s data transport network  100  in performing step  410  of the VLAN provisioning process. The functionality of VLAN provisioning step  410 , enables novice operators with little VLAN technology experience to efficiently and effortlessly perform VLAN provisioning.  
         [0077]    As an advanced feature associated with the data transport trunk link selection step  410  an analyst may also be provided with the opportunity to tailor the data transport trunk selection by adding and removing  412  selected data transport trunk links  208  via corresponding “Add/Remove Selected Trunk Link(s)” buttons  526 . Specifying data transport trunk links  208  to be excluded from a VLAN provisioning still saves time for the analyst compared to the prior art methods of specify the trunk ports  102  to be included in the VLAN, as there typically are fewer data transport trunk links  208  to excluded than to include. The fewer number of data transport trunk links  208  to be excluded stems from the preferred provisioning of VLANs over all data transport trunk links  208 .  
         [0078]    VLAN provisioning on data transport trunk links  208  is completed by pressing a “Commit Active VLAN to Selected Trunk Links” button  528  which implements functionality of VLAN provisioning step  414 . The corresponding VLAN provisioning status of the selected data transport trunk links  208  will initially show “Pending” as steps  426  and  428  of the VLAN provisioning process  400  are performed. Subsequent to performing steps  426 / 428  the VLAN provisioning status changes to “Committed”. The sequence of interaction provides for easy and efficient VLAN provisioning in the service provider network  100 .  
         [0079]    As mentioned above, besides attending to VLAN provisioning tasks, network management and service provisioning also includes data transport trunk link  208  provisioning. In accordance with the exemplary embodiment of the invention, every data transport trunk link  208  is to be configured to support data transport for all provisioned VLANs. Therefore all provisioned VLANs should also be provisioned over new data transport trunk links  208 .  
         [0080]    As data transport trunk link provisioning is done in parallel, by pressing the Refresh/Show All Trunk Links button  522 , all provisioned data transport trunk links  208  in the data transport network  100  are displayed irrespective of VLAN associativity. All newly provisioned data transport trunk links  208  are also shown in the trunk link list  520 . The operator may select the newly provisioned data transport trunk links  208  and operate an “Activate Selected Trunk Link(s)” button  530  to create an interaction context in which subsequent actions may be performed on the selected trunk links.  
         [0081]    A clash of adjectives is noted. It is pointed out that the activation of selected trunk links performed via pressing the button  530  refers to creating an interaction context in which subsequent human-machine interactions may be performed thereon; and not, to make the selected trunk links  208  part of the active in-use data transport topology. Only the spanning-tree protocol affects the inclusion of trunk links  208  in the active in-use data transport topology.  
         [0082]    With the selected newly provisioned data transport trunk links  208  activated for interaction therewith, the VLAN list  510  shows the VLANs associated therewith—in this case none will be displayed as the active trunk link  208  is newly provisioned. By operating the Refresh/Show All VLANs button  518  (not in the active customer interaction context) all VLANs, irrespective of customer association, are shown in the VLAN list  510 .  
         [0083]    In accordance with the exemplary embodiment of the invention, a single click of an “Add All VLANs” button  532  is sufficient to initiate VLAN provisioning of all provisioned VLANs in the service provider&#39;s data transport network  100  on the selected (active) newly provisioned data transport trunk links  208 , implementing functionality of VLAN provisioning step  444 . The functionality of VLAN provisioning step  444 , enables novice operators with little VLAN technology experience to efficiently perform VLAN provisioning.  
         [0084]    As an advanced feature associated with the VLAN selection step  444  an analyst may also be provided with the opportunity to tailor the VLAN selection by adding and removing  446  selected VLANs via corresponding “Add/Remove Selected VLAN(s)” buttons  534 . Specifying VLANs to be excluded from VLAN provisioning still saves time for the analyst as there typically are fewer VLANs to excluded than to include. The fewer number of VLANs to be excluded stems from the preferred VLAN provisioning over all data transport trunk links  208 .  
         [0085]    VLAN provisioning on the newly provisioned data transport trunk links  208  is completed by pressing a “Commit Selected VLAN(s) to Active Trunk Link(s)” button  536  which implements functionality of VLAN provisioning step  448 . The corresponding VLAN provisioning status of the selected data transport trunk links  208  will initially show “Pending” as steps  426  and  428  of the VLAN provisioning process  400  are performed. Subsequent to performing steps  426 / 428  the VLAN provisioning status changes to “Committed”. The sequence of interaction provides for easy and efficient VLAN provisioning in the service provider network  100 .  
         [0086]    In accordance with another implementation of the invention, the provisioning of all VLANs over newly provisioned data transport trunk links  208  is an automatic network management and service provisioning function performed without necessitating operator/analyst interaction.  
         [0087]    As new data transport trunk links  208  may be provisioned, data transport trunk links  208  may also be decommissioned. A “Delete Selected Trunk Link(s)” button  538  may be provided. In decommissioning a selected data transport trunk link  208 , all VLAN associations with the selected data transport trunk link  208  are removed only. The corresponding VLAN provisioning status may show that the selected data transport trunk links  208  are being decommissioned by specifying that no VLAN associations exist therewith. As data transport trunk links  208  may be decommissioned via other network management and service provisioning processes, it is understood that the sequence of operation just described may be performed automatically without necessitating operator/analyst attention.  
         [0088]    It is understood that provisioning new, and decommissioning data transport trunk links  208  triggers the spanning-tree algorithms to re-calculate the spanning-tree(s).  
         [0089]    Having activated a customer  504 / 452 , and a particular customer VLAN  514 / 462  for interaction therewith, an access port list  540  shows access ports  104  associated with the active customer VLAN. For a newly created VLAN, the access port list  540  would be empty.  
         [0090]    By operating a “Refresh/Show All Access Ports” button  542  all access ports  104  in the data transport network  100  are displayed in the access port list  540 . The status of each access port may only have a meaning with respect to the active customer VLAN. Other implementations of the access port VLAN status may be used without limiting the invention to the description presented herein.  
         [0091]    Using “Add/Remove Selected Access Port(s)” buttons  544  is sufficient to initiate VLAN provisioning of the active customer VLAN on the selected access ports  104 . VLAN provisioning on the selected access ports  104  is completed by pressing a “Commit Active VLAN(s) to Selected Access Port(s)” button  546  which implements functionality of VLAN provisioning step  434 . The corresponding VLAN provisioning status of the selected access ports  104  will initially show “Pending” as commands are issued to the affected access ports  104 . Subsequently the VLAN provisioning status changes to “Committed”. The presented sequence of interaction provides for easy and efficient VLAN provisioning in the service provider network  100 .  
         [0092]    Just as new data transport trunk links  208  can by provisioned in parallel with VLAN provisioning, so can access port provisioning ( 472 ). Therefore by operating the Refresh/Show All Access Ports button  542  without a context (no active customer VLAN), all provisioned access ports  104  are displayed in the access port list  540 . Newly provisioned access ports  104  bear a “New” VLAN provisioning status.  
         [0093]    By selecting ( 472 ) at least one access port  104  from the access port list  540  and operating an “Activate Selected Access Port(s)” button  550 , the VLAN list  510  displays VLANs associated with the active access port selection. For a newly provisioned access port  104  the VLAN list  510  will be empty.  
         [0094]    By operating the Refresh/Show All VLANs button  518 , the VLAN list  510  displays all customer VLANs and by operating the Add/Remove Selected VLAN(s) buttons  534  is sufficient to initiate VLAN provisioning of the customer VLAN(s) on the selected access ports  104  implementing functionality of the VLAN provisioning step  474 . VLAN provisioning on the selected access ports  104  is completed by pressing a “Commit Selected VLAN(s) to Active Access Port(s)” button  552  which implements functionality of VLAN provisioning step  434 . The corresponding VLAN provisioning status of the selected VLANs will initially show “Pending” as commands are issued to the affected access ports  104 . Subsequently the VLAN provisioning status changes to “Committed”. The presented sequence of interaction provides for easy and efficient VLAN provisioning in the service provider network  100 .  
         [0095]    As new access ports  104  may be provisioned, existing access ports  104  may also be decommissioned. A “Delete Selected Access Port(s)” button  556  may be provided. In decommissioning a selected access port  104 , all VLAN associations with the selected access port  104  are removed only. The corresponding VLAN provisioning status may show that the selected access ports  104  are being decommissioned by specifying that no VLAN associations exit therewith. As access ports  104  may be decommissioned via other network management and service provisioning processes, it is understood that the sequence of operation just described may be performed automatically without necessitating operator/analyst attention.  
         [0096]    Additional interactive elements may be provided for extracting to an electronic form and/or perhaps obtaining hard copies of the VLAN  510 , Trunk  520 , ad Access Port  540  lists enabling VLAN inventory reporting functionality.  
         [0097]    Attention is drawn to the Customer/VLAN name specifier associated with each VLAN list entry ( 510 ). VLAN names are used in identifying customer VLANs. Typically this specifier is populated with a Customer Identifier as shown but the invention is not limited thereto. The VLAN name specifier may not have a particular format, a requirement exists for the VLAN name to be unique. Therefore using the Customer ID alone for a VLAN customer owning a group of VLANs is not sufficient to provide data traffic differentiation.  
         [0098]    In interacting with the “Commit . . . ” buttons  528 ,  536 ,  546 ,  552 , etc., the VLAN provisioning further includes propagating the VLAN name/CustomerID specifier to the various provisioning database records held by field installed VLAN equipment. This includes the association of the VLAN name/Customer ID specification with the trunk ports  202 , access ports  104 , trunk link  208  definitions, etc. The propagation of the VLAN name/Customer ID into the network  100 , on performing VLAN provisioning, enhances maintainability of the provisioned VLAN services. The consistency in the propagation of VLAN name/Customer ID specifiers into the network  100  helps ensure data traffic differentiation between provisioned customer VLANs.  
         [0099]    A further “Refresh Global VLAN Status” button  560  may be provided. Operating the Refresh Global VLAN Status button  560 , displays all provisioned customer VLANs in the VLAN list  510  with the current VLAN status. In the event in which a particular VLAN identifier/VLAN name combination is associated with two different customers or any other VLAN provisioning discrepancies have occurred, the VLAN status displayed is “Error” otherwise the VLAN status is “Provisioned”. This provides (visual) feedback in ensuring that VLAN provisioning has been successfully completed across the data transport network  100 . An aggregation of all access port  104  operational statuses may also be included in the VLAN status.  
         [0100]    Dependent on the particular implementation, a wide variety of VLAN provisioning status states my be defined, probed for and detected. For example, it is possible for the “Pending” VLAN provisioning status to persist for some time or a provisioning error to occur. These instances may be the result of race conditions which have led to VLAN configuration conflicts and/or the result of a temporary unavailability of a subset of the VLAN equipment on which the VLAN provisioning is to have to effected. Subsequent activation of the “Commit . . . ” buttons  528 ,  536 ,  546 ,  552 , etc. may alleviate such and other anomalous instances. Nevertheless, the feedback provided via the VLAN provisioning status reporting functionality provided greatly reduce VLAN provisioning overheads by enabling an analyst to quickly identify, interpret, and address VLAN provisioning failures.  
         [0101]    Further details regarding VLAN provisioning steps 426 and 428 are described, without limiting the invention thereto, in: co-pending commonly assigned U.S. patent applications Ser. No. 10/021,080, filed on Dec. 19, 2001, entitled “NETWORK MANAGEMENT SYSTEM ARCHITECTURE”; co-pending commonly assigned U.S. patent application Ser. No. 10/021,629, filed on Dec. 19, 2001, entitled “METHOD OF INVOKING POLYMORPHIC OPERATIONS IN A STATICALLY TYPED LANGUAGE”; and co-pending commonly assigned U.S. patent applications Ser. No. 10/115,900, filed on Apr. 5, 2002, entitled “COMMAND LINE INTERFACE PROCESSOR” all of which are incorporated herein by reference. In summary, implementing the VLAN identifier associations pertaining provisioned VLANs includes issuing commands to network elements associated with the VLAN trunk ports  202  corresponding to the VLAN trunks  208  and VLAN access ports  104 . In using Command Line Interface (CLI) commands, all aspects of VLAN provisioning may be addressed.  
         [0102]    The embodiments presented are exemplary only and persons skilled in the art would appreciate that variations to the above described embodiments may be made without departing from the spirit of the invention. The scope of the invention is solely defined by the appended claims.