A method, comprising: receiving, at a first network, a first real-time communication initialization message from a first customer communication device operated by a first user; authenticating the first user at the first network; forwarding a second real-time communication initialization message from the first network to a second network, wherein the first network belongs to a first domain operated by a first entity and the second network belongs to a second domain operated by a second entity; and forwarding user authentication information from the first network to the second network such that the user authentication information is used by the second network in connection with processing one or more of i) the second real-time communication initialization message and ii) a communication session created with the second real-time communication initialization message; and wherein the user authentication information includes one or more of results of the authentication of the first user at the first network, an authentication certificate, an identity of the first user, and identification information associated with the first user, the method characterized by: mapping, by the second network, an identity of the first user in the first network to an identity of the first user in the second network; and utilizing the identity of the first user in the second network to retrieve user authentication information for the first user from a database in the second domain, wherein the user authentication information includes one or more of account number, billing information, payment information, communication history, and communication preferences. receiving, at a first network, a first real-time communication initialization message from a first customer communication device operated by a first user; authenticating the first user at the first network; forwarding a second real-time communication initialization message from the first network to a second network, wherein the first network belongs to a first domain operated by a first entity and the second network belongs to a second domain operated by a second entity; and forwarding user authentication information from the first network to the second network such that the user authentication information is used by the second network in connection with processing one or more of i) the second real-time communication initialization message and ii) a communication session created with the second real-time communication initialization message; and wherein the user authentication information includes one or more of results of the authentication of the first user at the first network, an authentication certificate, an identity of the first user, and identification information associated with the first user, the method characterized by: mapping, by the second network, an identity of the first user in the first network to an identity of the first user in the second network; and utilizing the identity of the first user in the second network to retrieve user authentication information for the first user from a database in the second domain, wherein the user authentication information includes one or more of account number, billing information, payment information, communication history, and communication preferences. mapping, by the second network, an identity of the first user in the first network to an identity of the first user in the second network; and utilizing the identity of the first user in the second network to retrieve user authentication information for the first user from a database in the second domain, wherein the user authentication information includes one or more of account number, billing information, payment information, communication history, and communication preferences.