A router for receiving and relaying initial Diameter session request and response messages from clients (11, 12, 13, 14) and servers (31, 32, 33) in an IMS network, respectively, the router being separate from the clients, the router comprising: a load balancing component operative to receive initial Diameter request messages and to relay initial Diameter request messages to a selected server in the network based on at least one routing policy; and a routing policy component operative to select a server of the network for routing of a given initial Diameter request message based at least partially on a type of IMS message session, application services, subscriber information, or billing information, wherein the routing policy component includes a traffic and load analysis component operative to dynamically monitor traffic load and an alive status of the servers, the routing policy component selecting the server for routing the given initial Diameter request message based at least partially on the traffic load and alive status of the servers; the routing policy component includes a home or visit network component operative to determine whether a new call session associated with the given initial Diameter request message is initiated by a caller from a home or visited network, the routing policy component selecting the server for routing the given initial Diameter request message based at least partially on whether the call session is initiated by a caller from a home or visited network; and the routing policy component includes a Diameter reference of points component operative to distinguish Diameter request messages and to identify suitable host servers in the network capable of providing services associated with the initial Diameter request message, and wherein the routing policy component selects the server for routing the given initial Diameter request message from the identified suitable host servers. a load balancing component operative to receive initial Diameter request messages and to relay initial Diameter request messages to a selected server in the network based on at least one routing policy; and a routing policy component operative to select a server of the network for routing of a given initial Diameter request message based at least partially on a type of IMS message session, application services, subscriber information, or billing information, wherein the routing policy component includes a traffic and load analysis component operative to dynamically monitor traffic load and an alive status of the servers, the routing policy component selecting the server for routing the given initial Diameter request message based at least partially on the traffic load and alive status of the servers; the routing policy component includes a home or visit network component operative to determine whether a new call session associated with the given initial Diameter request message is initiated by a caller from a home or visited network, the routing policy component selecting the server for routing the given initial Diameter request message based at least partially on whether the call session is initiated by a caller from a home or visited network; and the routing policy component includes a Diameter reference of points component operative to distinguish Diameter request messages and to identify suitable host servers in the network capable of providing services associated with the initial Diameter request message, and wherein the routing policy component selects the server for routing the given initial Diameter request message from the identified suitable host servers.