[vinay427]

I'm unclear why you claim that "private is not the only kind of call." [EDIT below to clarify.] Also, your IP address is only potentially revealed to your contacts, which is rather different from the Telegram situation in which another party that you don't specifically authorize has access to your data.

EDIT: What I meant by this, as upon re-reading it seems unclear, is that the privacy as I understand it is not supposed to protect one party from the other party with which they are communicating, but rather conceal the conversation from third parties.

[lxgr]

The confusion seems to stem from two kinds of privacy goals here: Metadata privacy towards third parties (i.e. who is calling who; Signal explicitly does not provide this) and reciprocal location privacy of two calling parties (i.e. I don't know where I am called from and vice versa, only who I am talking to).

Signal's conscious choice is to interpret a user adding another as a contact as an implicit signal to mark them trustworthy enough to forfeit the second kind of privacy in exchange for better voice quality (latency and bandwidth) as well as to lighten the strain on their resources.