Real-time chat service file transfer across different networks

A method of completing real-time chat service (RCS) file transfer, comprising:

• receiving, by a real-time chat session (RCS) server in a second communication network, a first message comprising a first uniform resource locator (URL) designating a file stored in a first message store in a first communication network;
• sending the first URL by the RCS server to a second message store in the second communication network;
• identifying a second URL by the second message store, wherein the second URL is to be associated with the first URL by a proxy server;
• sending the first URL and the second URL by the second message store to the proxy server;
• sending the second URL by the second message store to the RCS server;
• sending a second message comprising the second URL by the RCS server to a communication device engaged in a real-time chat session, whereby the communication device is enabled to request the file from the proxy based on the second URL;
• creating a mapping from the second URL to the first URL by the proxy server;
• storing the mapping from the second URL to the first URL by the proxy server;
• receiving a request for a file transfer by the proxy server from the communication device, wherein the request comprises the second URL;
• in response to receiving the request for the file transfer, looking up the first URL by the proxy server based on the second URL;
• retrieving a file stored at the first message store by the proxy server based on the first URL;
• and
• returning the retrieved file by the proxy server to the communication device.