Patent Abstract:
The invention is directed to configuring services in a packet switching network. Embodiments of the invention group existing service policies configured on network routers into policy groups, thereby enabling better management of service policies and policy overrides. This functionality can be useful for identifying redundant policies that may be eliminated by reconfiguring one or more of the network routers to reduce the overall network-wide number of policies, as well as provisioning new services in a manner that efficiently uses existing policies.

Full Description:
FIELD OF THE INVENTION 
     The invention is directed to packet switching networks (PSN), particularly to configuring services thereon using policies. 
     BACKGROUND OF THE INVENTION 
     Virtual Leased Line (VLL) is a service for providing Ethernet based point to point communication over Internet Protocol (IP) and Multi Protocol Label Switching (MPLS) networks (IP/MPLS). This technology is also referred to as Virtual Private Wire Service (VPWS) or Ethernet over MPLS (EoMPLS). VLL service provides a point-to-point connection between two Customer Edge (CE) routers. It does so by binding two attachment circuits (AC) to a pseudowire that connects two Provider Edge (PE) routers, wherein each PE router is connected to one of the CE routers via one of the attachment circuits. VLL typically uses pseudowire encapsulation for transporting Ethernet traffic over an MPLS tunnel across an IP/MPLS backbone. More information on pseudowires can be found in “Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture”, RFC3985, IETF, March 2005, by S. Bryant and P. Pate. 
     Virtual Private LAN Service (VPLS) is an Ethernet service that effectively implements closed user groups via VPLS instantiations. In order to achieve full isolation between the user groups, VPLS dedicates a separate database, usually in the form of a forwarding information base (FIB), on network routers per VPLS instance. Each VPLS instance further requires that a dedicated mesh of pseudowire tunnels is provisioned between PE routers that are part of the VPLS. 
     Both VLL and VPLS services use Service Access Points (SAP) to bind tunnel endpoints at PE routers ports to their respective service. For example, in the case of VPLS service a SAP would specify physical identifiers (e.g. node, shelf, card, port) of the corresponding port and an identifier (e.g. VLAN5) of the VPLS. 
     Services such as VPLS and VLL services provide the capability to securely communicate data packets among routers provisioned with the same service. Typically, thousands of such services are provisioned on a network, the data packet traffic that they each carry being kept separate from one another via special treatment provided at each router on which an instantiation of that service has been provisioned. 
     Each service has physical characteristics that in part define the service. These characteristics, also referred to a quality of service (QoS) parameters, include constant information rate (CIR), peak information rate (PIR), and maximum burst size (MBS) parameters and are often grouped into a policy for convenient provisioning of a service on a given router. 
     A service access point (SAP) provisioned on a router is used to associate a service instance with a port of the router and a policy. A SAP can also associate an override with a policy, wherein a value of one of the QoS parameters is specified to be used instead of the value for that QoS parameter defined by the associated policy. 
     Although policies and policy overrides are local to a router, it is desirable to define and use them on a network-wide basis for consistency. However, in a large network with thousands of routers, each having dozens of ports, and the even larger number of unique combinations of QoS parameter values that can be defined and assigned to these ports, limitations on the maximum number of policies that a network management (NM) system managing the network can support are easily exceeded. Using policy overrides to alleviate this problem only exacerbates difficulties in achieving network-wide consistency in the provisioning of services. Furthermore, since policies and policy overrides can be provisioned both locally at a router and centrally via a network management system, keeping the provisioning of services in synchronization at a NM system and network routers is difficult. Therefore, a means of configuring services on a PSN in a manner that ameliorates one or more of the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The invention is directed to configuring services in a packet switching network. Embodiments of the invention group existing policies configured on network routers into policy groups, thereby identifying redundant policies that may be eliminated by reconfiguring one or more of the network routers to reduce the overall network-wide number of policies. This functionality aims at efficient use of NM system resources to help avoid exceeding NM system policy limits. 
     One embodiment of the invention takes policy overrides into account during the grouping operation so that the policy overrides can be eliminated during the reconfiguration. This functionality aims at promoting consistent use of policies on a network-wide basis. 
     In one embodiment the grouping and reconfiguration is responsive to configuration changes initiated locally at a router, which are learned of via event notification from a NM system. This functionality aims at keeping router and NM system policies used in configuration of services in synchronization. 
     According to an aspect of the invention a method of configuring a service in a packet switching network is provided. The method includes the steps of: executing automatically instructions stored on a computer readable media, the instructions when executed causing a sequence of steps to be performed, the sequence comprising the steps of: determining a service access point to be affected by configuration of the service; obtaining policing information associated with the service access point from a router of the switching network; assigning the service access point to a policy group depending upon the policy information; updating, on the router in accordance with the assignment, provisioning information associated with the service access point to configure the service. 
     According to another aspect of the invention a system for configuring a service in a packet switching network is provided. The system comprises a service platform for executing a service application stored thereon, the service platform comprising: means for communicatively coupling to a network management entity of the packet switching network via an operating system interface; and a service database for storing a plurality of policy groups and their associated policies, wherein the service application comprises instructions stored on computer readable media to be executed by the service platform to cause a sequence of actions to be performed in cooperation with the management entity, the actions comprising: determining a service access point to be affected by configuration of the service; obtaining policing information associated with the service access point from a router of the switching network; assigning the service access point to a policy group depending upon the policy information; updating, on the router in accordance with the assignment, provisioning information associated with the service access point to configure the service. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiments, as illustrated in the appended drawings, where: 
         FIG. 1  illustrates a network configuration according to a first embodiment of the invention; 
         FIG. 2  illustrates a method of configuring services in a packet switching network according to a second embodiment of the invention; and 
         FIG. 3  illustrates a network configuration according to a third embodiment of the invention; 
     
    
    
     In the figures like features are denoted by like reference characters. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a network configuration  10  for providing a VPLS service over an MPLS network  12  includes a first pseudowire tunnel T 1  routed through the MPLS network  12  between a first provider edge router R 1  and a second provider edge router R 2 . A service instance SVC of the VPLS service is instantiated at each of the provider edge routers R 1 , R 2  and associates the first pseudowire tunnel T 1  with the VPLS service. Accordingly, data packets associated with the VPLS service are communicated through the MPLS network  10  via the first pseudowire tunnel T 1  between the first and second provider edge routers R 1 , R 2 . 
     The MPLS network  10  also includes a second pseudowire tunnel T 2  routed through the MPLS network  12  between the first provider edge router R 1  and a third provider edge router R 3 . A service instance SVC of the VPLS service is instantiated at the third provider edge router R 3  and associates the second pseudowire tunnel T 2  with the VPLS service. Accordingly, data packets associated with the VPLS service may also be communicated through the MPLS network  10  via the second pseudowire tunnel T 2  between the first and third provider edge routers R 1 , R 3 . 
     A first customer edge router CE 1  is connected to a first interface port P 1  of the first provider edge router R 1  via a first attachment circuit AC 1 . The first customer edge router CE 1  has a first MAC address X. Similarly, a second customer edge router CE 2  is connected to a second interface port P 2  of the second provider edge router R 2  via a second attachment circuit AC 2 . The second customer edge router CE 2  has a second MAC address Y. 
     A first service access point SAP 1  associates the first interface port P 1  with the VPLS service SVC. The first provider edge router R 1  includes a first database DB 1  associated with the service instance SVC. The first database DB 1  includes information that associates the service SVC provisioned on the first PE router R 1  with the first pseudowire tunnel T 1 . Data packets received at the first port P 1  from the first attachment circuit AC 1  that are associated with the VPLS service SVC are forwarded to the primary pseudowire tunnel T 1  in accordance with the information in the first database DB 1 . Such information includes the forwarding information, which in this case causes data packets with a source MAC address being the first MAC address X to be forwarded over the first pseudowire tunnel T 1  when their destination MAC address is the second MAC address Y. Similarly, data packets associated with the VPLS service SVC received by the first provider edge router R 1  from the first pseudowire tunnel T 1  are forwarded to the first interface port P 1  in accordance with information in the first database DB 1  and the first service access point SAP 1 . 
     Similarly, a second service access point SAP 2  associates the second interface port P 2  with the VPLS service SVC, such that data packets received at the second port P 2  from the second attachment circuit AC 2  that are associated with the VPLS service SVC are forwarded to the first pseudowire tunnel T 1  in accordance with information in the second database DB 2 . Such information includes forwarding information, which in this case causes data packets with a source MAC address being the second MAC address Y to be forwarded over the pseudowire tunnel T 1  when their destination MAC address is the first MAC address X. Similarly, data packets associated with the VPLS service SVC received by the second provider edge router R 2  from the first pseudowire tunnel T 1  are forwarded to the second interface port P 2  in accordance with information in the second database DB 2  and the second service access point SAP 2 . 
     Typically, there would be multiple pseudowire tunnels connecting multiple provider edge routers. In some cases these tunnels form a fully connected mesh interconnecting the provider edge routers. In any case, when there are multiple pseudowire tunnels for a given service that terminate on a provider edge router, a database is used at that router to determine over which of the tunnels a data packet should be forwarded to reach its destination. This determination is made based on the destination MAC or IP address of the data packet. A MAC address is a 48 bit address that is generally unique and dedicated to a given network interface card or adapter of a data communication system. A MAC address is also known as a hardware address. An IP address is a 32 bit (IPv4) or 128 bit (IPv6) address that is generally unique to a network interface or system but is assignable in software. 
     In view of foregoing it should be clear that data packets associated with the VPLS service SVC can be communicated between the first and second customer edge routers CE 1 , CE 2  via their respective attachment circuits AC 1 , AC 2 , the first and second provider edge routers R 1 , R 2 , and the first pseudowire tunnel T 1 . 
     A third customer edge router CE 3  is connected to the third provider edge router R 3  via a third attachment circuit AC 3  connected to a third interface port P 3  at the third provider edge router R 3 . The third customer edge router CE 3  has a third MAC address Z. In a similar manner as described earlier for the first and second service access points SAP 1 , SAP 2 , a third service access point SAP 3  associates the third interface port P 3  with the VPLS service SVC instantiated on the third provider edge router R 3 . 
     The third service access point SAP 3  associates the third interface port P 3  with the VPLS service SVC. The third provider edge router R 3  includes a third database DB 3  associated with the service instance SVC. The third database DB 3  includes information that associates the VPLS service SVC provisioned on the third provider edge router R 3  with the second pseudowire tunnel T 2 . Data packets received at the third port P 3  from the third attachment circuit AC 3  that are associated with the VPLS service SVC are forwarded to the second pseudowire tunnel T 2  in accordance with information in the first database DB 1 . Such information includes forwarding information, which in this case causes data packets with a source MAC address being the third MAC address Z to be forwarded over the second pseudowire tunnel T 2  when their destination MAC address is the first or second MAC addresses X, Y. Similarly, data packets associated with the VPLS service SVC received by the third provider edge router R 3  from the second pseudowire tunnel T 2  are forwarded to the third interface port P 3  in accordance with information in the third database DB 3  and the third first service access point SAP 3 . 
     As mentioned previously, the databases DB 1  to DB 3  include information that associates their respective service access points SAP 1  to SAP 3  and respective ports P 1  to P 3  with the VPLS service SVC. For example, the first database DB 1  includes a first entry E 1  that associates the first service access point SAP 1  with the first interface port P 1  and VPLS service SVC, as well as a an identifier of a first policy PID 1  on the first PE router R 1 . A second entry E 2  in the first database DB 1  includes quality of service parameters of the first policy PID 1 . For example these QoS parameters have the values PIR=100 kilobits per second (Kbps), CIR=50 Kbps, and MBS=200 Kbps. 
     Similarly, the second database DB 2  includes a third entry E 3  that associates the second service access point SAP 2  with the second interface port P 2  and VPLS service SVC, as well as an identifier of a second policy PID 2  on the second PE router R 2 . A fourth entry E 4  in the second database DB 2  includes quality of service parameters for the second policy PID 2 . For example these QoS parameters have the values PIR=110 kilobits per second (Kbps), CIR=50 Kbps, and MBS=200 Kbps. The second database DB 2  has a fifth entry E 5  which is an override policy OPID 2  of the second policy PID 2 . For example, the fifth entry E 5  defines a PIR=100 Kbps, which overrides the PIR value in the fourth entry E 4 . 
     Similarly, the third database DB 3  includes a sixth entry E 6  that associates the third service access point SAP 3  with the third interface port P 3  and VPLS service SVC, as well as an identifier of a third policy PID 3  on the third PE router R 3 . A seventh entry E 7  in the third database DB 3  includes quality of service parameters for the third policy PID 3 . For example these QoS parameters have the values PIR=200 kilobits per second (Kbps), CIR=50 Kbps, and MBS=200 Kbps. 
     Still referring to  FIG. 1 , the network configuration  10  includes a management entity  14  that is communicatively coupled to the provider edge routers R 1  to R 3  via a control connection  16  and the MPLS network  12 . The management entity  14  would typically be a network management system capable of performing operation, administration and maintenance (OAM) type functions on network elements in the MPLS network  12  such as the provider edge routers R 1  to R 3 . This functionality of the management entity  14  includes the capability to receive reports of equipment, service, and provisioning related events from network elements of the MPLS network  12 . The management entity  14  includes a management database MDB, which includes entries for the first, second, and third policies PID 1  to PID 3  and their respective QoS parameter values. 
     The network configuration  10  also includes a service platform  18  that is communicatively coupled to the management entity  14  via an open operating system (OS) interface  20 . Using the open OS interface  20 , the service platform  18  has access to event notifications  22 , which include event notifications related to the event reports from the network elements. Further using the open OS interface  20  the service platform  18  can issue control commands  24  to the management entity  14  including commands to effect provisioning changes at the provider edge routers R 1  to R 3 . The service platform  18  would typically be a laptop or desktop computer or workstation. The open OS interface is an Extensible Markup Language (XML) interface, although other types of message interfaces could be used. 
     The service platform  18  executes a service application  26  that is in communication with a service database  28  on the service platform  18 , although the service database  28  could also reside on the management entity  14  with access to it given by the open OS interface  20 . The service application  26  is a software program that embodies a method of configuring services in accordance with an embodiment of the invention. The service database  28  includes information on policy groups that have been derived according to the method. For example, this information includes an eighth entry E 8  for a first policy group PG 1  and a ninth entry E 9  for a second policy group PG 2 . 
     As indicated by the eighth entry E 8 , the first policy group PG 1  is associated with the first and second service access points SAP 1 , SAP 2 . A fourth policy PID 4  has been created based on QoS parameter values of the first and second policies PID 1 , PID 2  that are in common after taking any related override policies into account, specifically in this case the override policy OPID 2 . For example, the values of the QoS parameters of the fourth policy PID 4  are PIR=100, CIR=50, and MBS=200. Similarly, as indicated by the ninth entry E 9 , the second policy group PG 2  is related to the third service access point SAP 3 . A fifth policy PID 5  has been created based on QoS parameter values of the third policy PID 3 . The steps performed in order to derive the policy groups PG 1 , PG 2  will be described in more detail later with reference to  FIG. 2 . 
     After creating the policy groups PG 1 , PG 2  the service application  26  issues control commands  24  to the management entity  14  to cause their associated respective policies PID 4 , PID 5  to replace in the PE routers R 1  to R 3  and management database MOB the policies PID 1  to PID 3  on which the policy groups PG 1 , PG 2  were based. This is indicated in  FIG. 1  by the bold arrows and text. This replacement operation uses the identifiers of the policies to be replaced PID 1  to PID 3 , and may also use the service access points SAP 1  to SAP 3  for further correlation between the incoming PID 4 , PID 5  and outgoing policies PID 1  to PID 3 . For example, to make the replacement an identifier of the fourth policy PID 4  replaces that of the first and second policies PID 1 , PID 2  in the first and third entries E 1 , E 3 , respectively. Additionally, the policy information of the fourth policy PID 4 , such as the values of the QoS parameters PIR=100, CIR=50, MBS=200, replace those of the first and second policies PID 1 , PID 2  in the second and fourth entries E 2 , E 4 , respectively. In some cases, the policy information of the policy associated with the policy group to which the SAP is assigned may already exist on the router, in which case the policy previously associated with the SAP can be deleted if it is not associated with any other SAPs on the router. For example, if the fourth policy PID 4  already existed on the first router R 1  then the first policy PID 1  of the second entry E 2  could be deleted because that policy is not associated with any other SAP on the first router R 1 . Likewise, the same is true of unused policies in the management database MDB. The override policy OPID 2  is removed by deleting the fifth entry E 5 . Furthermore, an identifier of the fifth policy PID 5  replaces that of the third policy PID 3  in the sixth entry E 6 . Additionally, the policy information of the fifth policy PID 5 , such as the values of the QoS parameters PIR=200, CIR=50, MBS=200, replace those of the third policy PID 3  in the seventh entry E 7 . Finally, the fourth and fifth policies PID 4 , PID 5  with there associated QoS parameter values replace the first, second, and third policies PID 1 , PID 2 , PID 3  in the management database MDB. 
     Referring to  FIG. 2 , a method  200  of configuring services in a packet switching network will now be described with additional reference to  FIG. 1 . The method  200  includes an initial step of determining  202  routers that may be affected by operations that are carried out as part of the configuration of the services. This determination  202  could be the result of user input at the service platform  18  or management entity  14 . For example, an operator could specify the affected provider edge routers R 1  to R 3 . Additionally or alternatively, the affected routers could be derived by the service application  26  from event notifications  22  received over the open OS interface  20 . In this case the service application  26  would check the event notifications  22  to determine if any of them relate to provisioning of a policy or an override policy at the provider edge routers R 1  to R 3  or at the management entity  14 . In the affirmative, the affected routers would be determined from the event notifications  22 , either directly if explicitly indicated in the event notifications  22  or indirectly via information stored in the management database MDB or service database  28 . The service application  26  may additionally send control commands  24  to the management entity  14  to cause the management entity  14  to extract any relevant policy or policy override provisioning information from any router related to the event notifications  22 , or from the management entity  14  itself. 
     The method then proceeds to determining  204  service access points that may be affected by operations that are carried out as part of the configuration of the services. Typically, determining  204  the affected SAPs would be done based on the determination  202  of the affected routers. For example, the service application would send control commands  24  to the management entity to query which SAPs are provisioned on the affected routers. However, as with the prior step of determining  202  affected routers, the present step of determining  204  affected SAPs could be the result of user input at the service platform  18  or management entity  14 . For example, an operator could specify the affected service access points SAP 1  to SAP 3 . Additionally or alternatively, the affected SAPs could be derived by the service application  26  from event notifications  22  received over the open OS interface  20 . In either of the latter two cases, it is therefore possible to omit from the method  200  the step of determining  202  the affected routers. 
     The method then proceeds to obtain  206  policy information related to the affected SAPs. For example, the service application  26  issues control commands  24  to cause the management entity  14  to query network routers R 1  to R 3  for this policy information, such as that in the second, fourth, fifth, and seventh entries E 2 , E 4 , E 5 , E 7 , and provide the policy information to the to the service application  26 . 
     The method then proceeds to assigning  208  each affected SAP to an existing or new policy group depending upon the policy information obtained  206  in the previous step. This step is performed by the service application  26  on any given SAP by first applying to a policy specified for the SAP all override policies that correspond to that policy in order to update that policy, before searching in the service database  28  for a policy group that has QoS parameters that match those of the updated policy. If a matching policy group is found the SAP is assign to that matching policy group, otherwise a new policy group is created and the SAP is assigned to the new policy group. For example, in the case of the second service access point SAP 2 , the value of the QoS parameter PIR=110 in the second policy PID 2  is updated by the override policy OPID 2 , which has a QoS parameter value of 100. The updated second policy has QoS parameter values PIR=100, CIR=50, MBS=200, which match those of the first policy group PG 1 . The service application  26  therefore assigns the second service access point SAP 2  to the first policy group PG 1 , which is associated with the fourth policy PID 4 . In a similar manner the first service access point SAP 1  is assigned to the first policy group PG 1 , and the third service access point SAP 3  is assigned to the fifth policy PID 5 . 
     For each policy group and for each SAP assigned thereto, the method then proceeds to update  210  provisioning information of the SAP on a respective router with an identifier of the policy associated with the policy group as well update on the router any existing, or add any non-existing, policy information of the associated policy. For example regarding the first policy group PG 1 , the service application  26  issues control commands  24  to cause the management entity  14  to update provisioning information of the first service access point SAP 1  in the first entry E 1  by replacing the identifier of the first policy PID 1  with that of the fourth policy PID 4 . Likewise, the policy information of the fourth policy PID 4  is added to the first router R 1  by replacing the information of the first policy PID 1  in the second entry E 2  with that of the fourth policy PID 4 . In a similar manner, the provisioning information of the second access point SAP 2  is updated in the second router to reflect assignment of the second service access point SAP 2  to the first policy group PG 1 . Likewise, the provisioning information of the third access point SAP 3  is updated in the third router to reflect assignment of the third service access point SAP 3  to the second policy group PG 2 . 
     The method then proceeds to remove  212  any unused policies and policy overrides from routers affected by the updating  210  of provisioning information of the previous step. For example, the service application  26  issues control commands  24  to cause the management entity to remove the override policy OPID 2  of the fifth entry E 5 . 
     Finally, any unused policies are removed  214  from the management entity  14 . For example, the service application  26  issue control commands  24  to cause the management entity to remove the first, second, and third policies PID 1 , PID 2 , PID 3  from its management database MDB. 
     By executing the method  200 , the service platform  18  provides several advantages such as: more consistent use of policies on a network-wide basis, efficient use of NM system resources to help avoid exceeding NM system policy limits, and keeping router and NM system policies in synchronization. For example, with regard to the network configuration of  FIG. 1 , the total number of policies and policy overrides was reduced by 50%; from four to two. Although this was a simplistic example, it should illustrate that advantages provided by embodiments of the invention applied to a network with thousands of policies and routers can be quite significant. 
     Referring to  FIG. 3 , the network configuration  10  is the same as that in  FIG. 1  except for the first to ninth entries E 1  to E 9  in the in the first to third databases DB 1  to DB 3  and service database  28  have been replaced with new entries, as will be explained in the following description. Some of these new entries have content that is changed at various points in time, while others are added or removed at various points in time. The points in time are sequential and are designated respectively as first to fifth time points Time 1  to Time 5 . 
     According to  FIG. 3 , the first database DB 1  has a tenth entry E 10  that associates the first access point SAP 1  with a sixth policy PID 6 . An eleventh entry E 11  in the first database defines QoS parameters of the sixth policy PID 6  to be PIR=100, CIR=50, and MBS=200. A twelfth entry E 12  in the first database DB 1  defines a first override O 1 PID 6  for the sixth policy PID 6 , wherein a first override PIR value is defined as PIR=120. Likewise, the second database DB 2  has a thirteenth entry E 13  that associates the second access point SAP 2  with the sixth policy PID 6 . A fourteenth entry E 14  in the second database defines QoS parameters of the sixth policy PID 6  to be PIR=100, CIR=50, and MBS=200. A fifteenth entry E 15  in the second database DB 2  defines a second override O 2 PID 6  for the sixth policy PID 6 , wherein a second override PIR value is defined as PIR=110. 
     At the first time point Time 1 , the service application  26  obtains policy information regarding the first and seconds service access points SAP 1 , SAP 2  from the first and second databases DB 1 , DB 2  in a manner as previously described with reference to  FIG. 1  and  FIG. 2 . The service application applies the first and second overrides for the sixth policy O 1 PID 6 , O 2 PID 6  before assigning the first and second access points SAP 1 , SAP 2  to new or existing policy groups, again in the same manner as previously described. The resultant policy group assignment is stored in the service database  28 , for example as a sixteenth entry E 16 . In this case two new policy groups are created, a third policy group PG 3  for the first service access point SAP 1  and a fourth policy group PG 4  for the second service access point because of their different PIR values that result when their respective override policies O 1 PID 6 , O 2 PID 6  are applied. 
     At the second time point Time 2 , the first override PIR in the twelfth entry E 12  is changed to 140, and the second override PIR in the fifteenth entry E 15  is also changed to 140. These changes are shown in the figure by the boldface arrow and text. 
     At the third time point Time 3  the service application  26  again obtains policy information regarding the first and second service access points SAP 1 , SAP 2  from the first and second databases DB 1 , DB 2 . The service application  26  applies the first and second PIR overrides (PIR=140) before assigning the first and second access points SAP 1 , SAP 2  to new or existing policy groups. The resultant policy group assignment is stored in the service database  28 , for example as a seventeenth entry E 17  which replaces the sixteenth entry E 16  since that entry is no longer relevant. In this case a new policy group is created, a fifth policy group PG 5 , and both the first and second service access points SAP 1 , SAP 2  are associated with this group PG 5 . For clarity of this description the new policy group was assigned a new number, e.g. PG 5 , however it should be appreciated that an already used policy group number could have been used, e.g. PG 3 , PG 4 , if all entries specifying that policy group have already been deleted (e.g. E 16 ) from the service database  28 . 
     At the fourth time point Time 4 , the third database is provisioned with the third service access point SAP 3  and policy information that associates it with the sixth policy PID 6 . This result of this provisioning is shown as an eighteenth entry E 18 , which defines the third service access point SAP 3  and associates it to the sixth policy PID 6 , and a nineteenth entry E 19 , which provides the QoS parameters of the sixth policy as being PIR=140, CIR=50, MBS=200. This provisioning could be accomplished by entering information of the eighteenth and nineteenth entries directly at the third router R 3 , or entering that information at the management entity  14 , or by specifying at the service platform  18  that the information of the fifth policy group PG 5  should be used. In the later case, the provisioning would be effected as previously described, that is, by the service application  26  issuing control commands  24  to the management entity  14  to effect the provisioning. 
     At the fifth time point Time 5 , the service application  26  obtains policy information regarding the first to third service access points SAP 1  to SAP 3  from the first to third databases DB 1  to DB 3 . The service application  26  applies the first and second PIR overrides (PIR=140) before assigning the first and second access points SAP 1 , SAP 2  to new or existing policy groups. The resultant policy group assignment is stored in the service database  28 , for example as a twentieth entry E 20  which replaces the seventeenth entry E 17  since that entry is no longer relevant. In this case an existing policy group is used, the fifth policy group PG 5 , and the first to third service access points SAP 1  to SAP 3  are assigned with this group PG 5  since the policy information of each specifies the same policy, the sixth policy PID 6 , and their QoS parameters have the same values, namely PIR=140, CIR=50, and MBS=200. 
     From the foregoing description with reference to  FIG. 3 , it should be appreciated the service application  26  with the method of configuring services that it embodies, is useful for promoting consistent use of policies on a network-wide basis, both in dealing with override policies on existing services, e.g. with regard to the first and second routers R 1 , R 2 , and in adding new services, e.g. with regard to the third router R 3 . The policy groupings, e.g. PG 1  to PG 5 , in the service database  28  can be considered as virtual groups in that they are not configured directly per se on the network routers, e.g. R 1  to R 3 , and the management entity  14 , but rather are created dynamically when needed, for example at request of a user or responsive to a configuration change detected via an event notification  22 . 
     Numerous modifications, variations and adaptations may be made to the embodiment of the invention described above without departing from the scope of the invention, which is defined in the claims.

Technology Classification (CPC): 7