Starting just before Update 30, Warframe included network updates to the way the game transmits data between players and servers. These updates increase the security of our game traffic as part of our campaign to fully support Warframe on new-generation consoles.
Unfortunately, the way Internet Service Providers are configured in some parts of the world- principally Egypt, according to our data- causes interference with the secure connections Warframe requires. This may cause you to be unable to see or join multiplayer sessions, or to see other players online.
We are looking at workarounds to address this in the game client, but currently we do not have a date for when you can expect this to be fixed. Other network-related alternatives may be available to you in the meantime. We regret the frustration that this has caused some of you, but ultimately we do not control the internet, and we must do our best to work within the limitations that are set for us.