Subspace communication

Subspace communication is a method of communication betweeb to points by sending the information through subspace.

Ancients
The Ancients developed subspace comunicators for use among their starships and their city-ships such as Atlantis. They also developed a Intergalactic communication device that link users extragalactically.

Asgard
The Asgard used less envasive subspace communicators, allowing them to communicate between galaxies as well. A platform would allow them to communicate with a hologram of one individual with a group of people.

Goa'uld
The Goa'uld used communication spheres to communicate between stars. It would allow them to communicate with each other visually.

Replicators
The Replicators were linked through together through a subspace communication network, which is what allowed them to store information so quickly. It also allowed them to upload "immunities" to weapons that they encountered.