I think this is a common open protocol that allows many small networks to talk to each other without giving up control completely so that they can use their own internal protocol. Therefore, SMTP and XMPP are federated protocols.
I could not find an exact definition anywhere, but I have evidence to support my claims:
Dictionary for the definition of the verb "to federate":
(with reference to several states or organizations) are formed or are being formed into a single centralized unit within which each state or organization retains some internal autonomy.
The latest Open Whisper Systems blog post discusses federated and centralized networks:
Indeed, the ban on integrating the application layer protocol into a centralized service is an almost sure recipe for a successful consumer product today. This is what Slack did with IRC, what Facebook did with email, and what WhatsApp did with XMPP. In each case, a federal service is stuck in time, while centralized service can move into the modern world further.
This page refers to SMTP as a "federated email protocol":
Then came SMTP (Simple Mail Transfer Protocol) and allowed these systems to merge into one large mail system.
(In addition to this: although I am not from the United States, it is easiest for me to think about this term by analogy with the American “federal government”: it allows all US states to coordinate their actions at the national level, while maintaining a lot of internal control)
Vicky chijwani
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