Instant messaging interoperability between disparate service providers

A method for performing instant messaging and identifying presence status with an external network distinct from a primary network, the method comprising the steps of:

• receiving an add request from a primary network user of the primary network;
• in response to receiving the add request from the primary network user of the primary network, sending a subscribe request to an external network user of the external network;
• in response to sending the subscribe request to the external network user of the external network, receiving an acceptance of the subscribe request from the external network user;
• in response to receiving the acceptance of the subscribe request from the external network user, receiving, from the external network, information indicative of a presence of the external network user;
• after receiving the information indicative of the presence of the external network user, initiating, by the primary network user, an instant messaging session between the primary network user and the external network user to allow the primary network user and the external network user to perform instant messaging communications;
• subsequent to initiating, by the primary network user, the instant messaging session, receiving, from the primary network user, an instant messaging communication for receipt by the external network user;
• and
• in response to receiving the instant messaging communication, sending, to the external network user, the instant message communication.

A system for performing instant messaging and identifying presence status with an external network, the system comprising the steps:

• a primary network including a plurality of servers,
• wherein the primary network is distinct from the external network;
• a processor programmed to perform a method of performing the instant messaging and identifying the presence status, the method comprising the steps of:
• receiving an add request from a primary network user of the primary network;
• in response to receiving the add request from the primary network user of the primary network, sending a subscribe request to an external network user of the external network;
• in response to sending the subscribe request to the external network user of the external network, receiving an acceptance of the subscribe request from the external network user;
• in response to receiving the acceptance of the subscribe request from the external network user, receiving, from the external network, information indicative of a presence of the external network user;
• after receiving the information indicative of the presence of the external network user, initiating, by the primary network user, an instant messaging session between the primary network user and the external network user to allow the primary network user and the external network user to perform instant messaging communications;
• subsequent to initiating, by the primary network user, the instant messaging session, receiving, from the primary network user, an instant messaging communication for receipt by the external network user;
• and
• in response to receiving the instant messaging communication, sending, to the external network user, the instant message communication.