FIELD OF THE INVENTION  
       [0001]     The present invention relates to a method and apparatus for routing contacts between a plurality of contact centres in a communications network.  
       BACKGROUND TO THE INVENTION  
       [0002]     Call centers are known in which incoming calls are routed to one of a plurality of agents. For example, the call center might provide help desk facilities for a particular group of products and customers who are able to call in and be allocated to an agent who has the necessary skills to deal with his or her query. Each agent has one or more skills, for example, a particular agent has knowledge about sales for product X and about technical support for product Y. An incoming call is received and information from that call used by the call center, together with information about the agents, in order to route the incoming call to an agent with the appropriate skill. For example, an interactive voice response system (IVR system) may be used to find out what type of agent skill is required. Associated with each skill is a queue into which incoming calls are placed until an agent with that skill becomes available.  
         [0003]     The terms “call center” and “contact center” as used herein are not intended to be restricted to situations in which telephone calls are made to the center. Other types of call or contact are also envisaged, such as email, fax, SMS, chat, web access and any other suitable method of contact including conventional telephone calls and voice over internet protocol telephone calls. Similarly, the terms “call” and “contact” as used herein are not intended to be restricted to conventional telephone calls but include contacts made by email, fax, voice over IP and any other suitable medium.  
         [0004]     It is known to use a network of contact centres and to route contacts from one of those contact centres to another contact centre in the network. For example, if one contact centre is particularly busy, contacts can be routed to another less busy contact centre. In this type of network of contact centres so called “network skillsets” also known as “workgroups” are often used. Agents with particular knowledge and ability can be members of a network skillset despite being associated with different contact centres in the network. For example, suppose there is a network skillset for agents who speak French. Agents can be allocated to that network skillset despite being located at different call centres, provided they speak French. Incoming contacts that require service by a French speaking agent can then be allocated to any of the agents in the French network skillset. A particular agent can be a member of more than one different network skillset.  
         [0005]     As the volumes of traffic increase to call centers and the number of different agent skills increases the complexity of routing incoming contacts to the appropriate, queues increases. In addition, there is a need to balance workload between not only the different contact centres in the network but also between agents in network skillsets.  
         [0006]     Recently such load balancing between agents in a network skillset has become a particular problem. Not only is there a need to ensure efficient use of agent resources in the network skillset but increasingly labour law and union requirements mean that work must be shared between agents in an equitable manner.  
         [0007]     As described in the following three US patent documents U.S. Pat. Nos. 5,546,452; 5,878,130; 5,848,143 a central controller is used to collect information from all contact centres in a network. That processor then receives all incoming contacts and routes those to the contact centres on the basis of the collected information and an optimisation algorithm or strategy. For example, these three patent documents describe seeking to route a contact to the highest skilled and longest available (i.e. longest inactive) agent in a workgroup. However, a problem with this approach is that there is no guarantee that the contact will be successfully routed to the longest inactive agent in the workgroup. If the chosen agent has in the meantime become active with another contact, the pending contact risks being dropped. This leads to customer dissatisfaction and potential loss of business. Alternatively, if the chosen agent is no longer inactive, the pending contact is routed to a different agent with the result that the required load balancing is not achieved.  
         [0008]     Another problem with the approach described in these three patent documents is that a central controller must be provided to which status information from all contact centres is sent. In addition, all incoming contacts need to be routed via the central controller. This is a complex approach which requires additional network equipment, increases traffic requirements in the network and is not robust because failures at the central controller affect the whole process.  
       OBJECT TO THE INVENTION  
       [0009]     The invention seeks to provide a method and apparatus for routing contacts between a plurality of contact centres in a communications network which overcomes or at least mitigates one or more of the problems noted above.  
         [0010]     Further benefits and advantages of the invention will become apparent from a consideration of the following detailed description given with reference to the accompanying drawings, which specify and show preferred embodiments of the invention.  
       SUMMARY OF THE INVENTION  
       [0011]     As mentioned above, load balancing between agents in a network skillset has become a particular problem. Not only is there a need to ensure efficient use of agent resources in the network skillset but increasingly labour law and union requirements mean that work must be shared between agents in an equitable manner. The present invention addresses these problems by using a source contact node in a network of contact centres to request nodal longest idle agent information from the other contact centres in the network. Using this information a network longest idle agent is identified and the incoming contact routed to that agent. A reservation system is used in combination with the longest idle agent information in order to prevent dropped contacts and to ensure equal sharing of work between agents in a network skillset. Contact centre servers are linked over a separate network, isolated from a network linking the contact centre switches. This enables real-time communications between the contact centre servers to quickly and effectively share the nodal longest idle agent information and/or other contact centre management information, statistics, parameters or “intrinsics”.  
         [0012]     According to an aspect of the present invention there is provided a method of routing a contact in a network comprising a plurality of contact centres, said method comprising the steps of: 
        receiving a contact at one of the contact centres, said contact centre being a source contact centre;     sending a reservation request from the source contact centre to each of the contact centres, said reservation request being for an agent with a specified relative intrinsic value;     for one or more of the reservation requests, receiving at the source contact centre, a value of the specified intrinsic and an associated agent identifier;     routing the received contact to one of the agents on the basis of the received intrinsic.        
 
         [0017]     This provides the advantage that load balancing can be achieved in a particular manner on the basis of intrinsics such as longest idle agent, average answer delay, calls queued count, calls answered count, number of idle agents, expected wait time and logged-in agent count. By using the reservation requests in conjunction with the intrinsic it is possible to ensure that the load balancing method based on the particular intrinsic is implemented correctly.  
         [0018]     According to another aspect of the invention there is provided a method of routing a contact in a network comprising a plurality of contact centres, said method comprising the steps of: 
        receiving a contact at one of the contact centres, said contact centre being a source contact centre;     sending a reservation request from the source contact centre to each of the contact centres, said reservation request being for a nodal longest idle agent;     for one or more of the reservation requests, receiving at the source contact centre, a nodal longest idle time and associated agent identifier;     routing the received contact to the agent with the longest of all the received nodal longest idle times.        
 
         [0023]     This provides the advantage that true “longest idle agent” routing is achieved and work is allocated equally between agents to meet union or other requirements. By using the reservation requests in conjunction with the longest idle agent information it is possible to ensure true “longest idle agent” routing rather than a “next best” or “pragmatic working” alternative.  
         [0024]     Preferably the method further comprises the step of cancelling unused reservations. This frees up reserved agents for other incoming contacts.  
         [0025]     Preferably the contact is received at any one of the contact centres. This is advantageous because it is not necessary to configure one of the contact centres (or one particular node) to receive all the incoming contacts. This reduces the amount of processing needed at any one of the contact centres and provides a robust system because for example, contacts can still be successfully routed despite failure at one of the contact centres.  
         [0026]     Preferably said contact is associated with a specified network skiliset and wherein said reservations requests are also for agents of that specified skillset. This provides the advantage that equal allocation of work can be achieved for agents in a network skillset, despite the fact that those agents are spread throughout the network.  
         [0027]     According to another aspect of the present invention there is provided a contact centre suitable for use in a network of contact centres, said contact centre comprising: 
        an input arranged to receive a contact;     an output arranged to send a reservation request to one or more contact centres in the network of contact centres, said reservation request being for an agent with a specified relative intrinsic value;     a second input arranged to receive, for one or more of the reservation requests, a value of the specified intrinsic and an associated agent identifier;     a processor arranged to route the contact to one of the agents on the basis of the received intrinsic.        
 
         [0032]     According to another aspect of the invention there is provided a contact centre suitable for use in a network of contact centres, said contact centre comprising: 
        an input arranged to receive a contact;     an output arranged to send a reservation request to one or more contact centres in the network of contact centres, said reservation request being for a nodal longest idle agent;     a second input arranged to receive, for one or more of the reservation requests, a nodal longest idle time and associated agent identifier;     a processor arranged to route the contact to the agent with the longest of all the received nodal longest idle times.        
 
         [0037]     According to another aspect of the invention there is provided a communications network comprising a plurality of contact centres as described above. Preferably, each of said contact centres comprises a contact centre server and a switch. The contact centre servers are advantageously linked to one another by a first part of said communications network and said switches are linked to one another by a second part of said communications network, said first and second parts being substantially isolated from one another. This provides the advantage that signalling traffic between the contact centre servers is insulated from all other types of traffic. In this way information about intrinsic values such as longest idle agent information is quickly and simply passed between contact centre servers.  
         [0038]     It is also preferred that each contact centre server is connected to its associated switch using a dedicated embedded local area network connection. In this way signalling traffic between a switch and its associated server is insulated from all other types of signalling such as inter-contact centre server signalling or signalling between a contact centre server and an administrator client server.  
         [0039]     The invention also provides for a system for the purposes of digital signal processing which comprises one or more instances of apparatus embodying the present invention, together with other additional apparatus.  
         [0040]     The preferred features may be combined as appropriate, as would be apparent to a skilled person, and may be combined with any of the aspects of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0041]     In order to show how the invention may be carried into effect, embodiments of the invention are now described below by way of example only and with reference to the accompanying figures in which:  
         [0042]      FIG. 1  is a schematic diagram of a network of contact centres suitable for use with the present invention;  
         [0043]      FIG. 2  shows the network of  FIG. 1  and includes arrows indicating a flow of messages through the network;  
         [0044]      FIG. 3  is a flow diagram of a method of routing a contact in a network of contact centres such as that of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF INVENTION  
       [0045]     Embodiments of the present invention are described below by way of example only. These examples represent the best ways of putting the invention into practice that are currently known to the Applicant although they are not the only ways in which this could be achieved.  
         [0046]     The term “nodal longest idle agent (LIA)” is used to refer to an agent who is not actively dealing with a contact and, of all the agents associated with the same contact centre server, has been in this idle state for the longest time.  
         [0047]     The term “network longest idle agent” is used to refer to an agent who is not actively dealing with a contact and, of all the agents in a network of contact centres, has been in this state for the longest time.  
         [0048]     The term “longest idle time” means the time for which the longest idle agent has been idle. For example, longest network idle time is the time for which the network longest idle agent has been idle.  
         [0049]     The term “intrinsic” means an item of information about a contact centre such as a statistic or parameter. Examples include nodal longest idle agent, average answer delay, calls queued count, calls answered count, number of idle agents, expected wait time and logged-in agent count.  
         [0050]     Average answer delay is an indication of how quickly a particular agent answers a contact that is routed to him or her.  
         [0051]     Calls queued count is the number of calls or contacts queued for a particular agent.  
         [0052]     Calls answered count is the number of calls or contacts answered within a specified time period, either by a particular agent or by a contact centre as a whole.  
         [0053]     Number of idle agents is the number of agents at a specified contact centre who are inactive at a particular time.  
         [0054]     Expected wait time is an indication of how long it will take for a contact to be routed to an available agent at a particular time. If agents are available to serve a call when it arrives, this parameter is zero.  
         [0055]     Logged-in agent count is the number of agents, either for a particular network skillset or for a particular contact centre, that are logged-in at a particular time.  
         [0056]      FIG. 1  is a schematic diagram of a plurality of contact centres  10 ,  11 ,  12  in a communications network  5 . Each contact centre comprises a call centre server  14  and a switch  15 . Any suitable type of call centre server can be used. The switches  15  are arranged to receive incoming contacts and route these to the associated call centre server  14 . Each switch  15  is connected to a plurality of agent stations as known in the art and is instructed to route incoming contacts either to those agent stations or to other contact centre servers  14  in the network by the contact centre server. Any suitable type of switch can be used. For example, if the contact centre is a multi-media contact centre means is provided for contacts of different media type to reach the contact centre server as known in the art.  
         [0057]     In the example illustrated in  FIG. 1  each contact centre server is connected to its associated switch using a dedicated embedded local area network (ELAN) connection. This provides the advantage that signalling traffic between the switch and its associated server is insulated from all other types of signalling (e.g. inter-contact centre server signalling (CLAN signalling) or signalling between a contact centre server and admin client servers); thus the engineering limits for ELAN traffic do not have to take these other forms of signalling into account and are defined solely on the basis of incoming call traffic. Communication between the contact centre server and the switch takes place using any suitable protocol as known in the art.  
         [0058]     In a preferred embodiment, the contact centre servers are linked to one another using a CLAN  17  (customer LAN) which is isolated from the connections between each of the contact centre servers and its associated switch. This substantial isolation or insulation is implemented for capacity reasons equivalent to those explained above with reference to the ELAN connections. In addition, the switches  15  are linked to one another using trunks  18  supporting any suitable communications protocol. The network between the switches is provided to connect voice channels between terminals which reside on different switches. The CLAN network between the contact centre servers is used to exchange signalling information on calls (e.g. for the contact centre servers to agree which node will receive a call). Once the source node decides where a call will be routed, a path such as a speech path for example is connected between the source and target switches.  
         [0059]     A Network Control Centre (NCC) server  19  is also provided. This is connected to the CLAN such that it can communicate with each of the contact centre servers  14 . However this NCC is not connected to the switches  15 . The NCC  19  creates routing tables  20  and propagates these to each of the contact centre servers  14  as known in the art.  
         [0060]     As mentioned above, each of the switches  15  is arranged to enable incoming contacts to reach the associated contact centre server  14 . This is illustrated in  FIG. 2  which shows a user terminal  25  connected to a public switched telephone network  26  which is in turn connected to one of the switches  15 .  FIG. 2  also shows agents  27  connected to the switches  15 .  
         [0061]     A method of routing a contact in the communications network of  FIG. 2  is now described. A customer using the terminal  25  places a call to source contact centre A over the PSTN  26 . This is illustrated by dotted line  30  in  FIG. 2 . The contact is held at switch  15  of the source contact centre whilst the contact centre server  14  at that source queues the incoming contact to all the other contact centre servers  14  in the network as well as to itself. This is illustrated by arrows  32  in  FIG. 2 . This process requests a reservation for an agent associated with a particular intrinsic value. Any suitable intrinsic value can be used such as the nodal longest idle agent, average answer delay, calls queued count, next-but-one longest idle agent, or similar at each of the contact centres. The requests are sent over the CLAN  17  to each contact centre server  14  and from there to each switch  15  using a reserve message over the dedicated ELAN  16 . Any suitable reserve message can be used.  
         [0062]     The source contact centre A waits for a response from each of the contact centre servers  14  over the CLAN  17 . These responses comprise an identifier for each agent associated with the particular intrinsic value (e.g. nodal longest idle agent) as well as the intrinsic value itself (e.g. nodal longest idle time). Using this information the source contact centre A determines a network-wide value of the intrinsic such as the network longest idle agent time. It then instructs its associated switch  15  to route the incoming contact to the associated agent. For example, the network longest idle agent. If this agent is at a different contact centre then the contact is routed to the relevant switch  15  over the trunks. For example, line  33  in  FIG. 2  illustrates a contact being transferred from contact centre A to an agent  27  at another contact centre.  
         [0063]     This method is now described in more detail with reference to  FIG. 3 . A contact arrives at a source contact centre (see box  40 ). The source contact centre then sends a queuing request to all other contact centres (see box  41 ), including itself, to request and reserve an agent associated with a particular intrinsic value. Any intrinsic may be used as mentioned above, for example, the nodal longest idle agent. The queuing request requires the contact centres to determine the nodal longest idle agent, to send back an identifier for that agent together with the nodal idle agent time, as well as making a reservation for that agent. The source contact centre waits for a pre-specified time. If, during that time, one or more of the other contact centres have returned nodal longest idle agent information (or other intrinsic information as mentioned above), the source contact centre compares the nodal longest idle times to find the greatest. This is the network longest idle agent time. The source contact centre is then able to instruct its associated switch to route the contact to the network longest idle agent (see box  42 ).  
         [0064]     If no contact centres return nodal longest idle agent information during the pre-specified time, this means that no suitable agents are currently available. In that case, the source contact centre server A waits for the first response it receives. This first response will be for the network longest idle agent because no other suitable agents are available. In that case the contact is routed to the agent identified in the first response (see box  43 ).  
         [0065]     Preferably the method is carried out for particular network skillsets. In that case, the incoming contact requires a specified network skillset, as determined by an interactive voice response (IVR) system or other suitable means. The source contact centre sends reservation requests to only those contact centres which have members of the required network skillset and the reservation requests and longest idle agent information are all specific to the particular network skillset.  
         [0066]     Advantageously, the source contact centre server places reservations at the other contact centre servers. This ensures that when the contact is eventually routed to the network longest idle agent, that agent is available and the contact is not dropped. This is achieved without the need for a central controller as in the prior art and a simple, robust system results. In addition, by using the reservation method in combination with the intrinsic information in a distributed manner it is possible to guarantee a specified distribution of contacts between agents in a network skillset. For example, the amount of work can be shared equally between agents in a network skillset, by ensuring new work is always allocated to the network longest idle agent.  
         [0067]     Once the incoming contact has been routed to the selected agent the unused reservations at any of the other contact centres are cancelled by the source contact centre server.  
         [0068]     Preferably, each contact centre server is arranged to continually monitor for intrinsic values in each skillset. It is then able to provide this information immediately on request from the source contact centre. In this manner the process of routing the contact to a chosen agent is able to operate in real time. Communication between the contact centre servers via the CLAN is separate from communication between the switches  15 . This facilitates inter contact centre server communication in order that the agent selection is achieved quickly and effectively in real time.  
         [0069]     In the embodiments described above the intrinsic “longest idle agent” is mentioned. However, it is also possible to use different intrinsics such as average answer delay or calls queued count. Also, it is possible to use an intrinsic such as the “next-but-one longest idle agent” in order to achieve a workable result.  
         [0070]     Any range or device value given herein may be extended or altered without losing the effect sought, as will be apparent to the skilled person for an understanding of the teachings herein.
Load balancing between agents in a network skillset has become a particular problem. Not only is there a need to ensure efficient use of agent resources in the network skillset but increasingly labour law and union requirements mean that work must be shared between agents in an equitable manner. A source contact node in a network of contact centres requests nodal longest idle agent information from the other contact centres in the network. Using this information a network longest idle agent is identified and the incoming contact routed to that agent. A reservation system is used in combination with the longest idle agent information in order to prevent dropped contacts and to ensure equal sharing of work between agents in a network skillset. Contact centre servers are linked over a separate network, isolated from a network linking the contact centre switches.