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+<a id="dir-spec.txt-3.4"></a>
+
+# Exchanging votes
+
+Authorities divide time into Intervals.  Authority administrators SHOULD
+try to all pick the same interval length, and SHOULD pick intervals that
+are commonly used divisions of time (e.g., 5 minutes, 15 minutes, 30
+minutes, 60 minutes, 90 minutes).  Voting intervals SHOULD be chosen to
+divide evenly into a 24-hour day.
+
+Authorities SHOULD act according to interval and delays in the
+latest consensus.  Lacking a latest consensus, they SHOULD default to a
+30-minute Interval, a 5 minute VotingDelay, and a 5 minute DistDelay.
+
+Authorities MUST take pains to ensure that their clocks remain accurate
+within a few seconds.  (Running NTP is usually sufficient.)
+
+The first voting period of each day begins at 00:00 (midnight) UTC.  If
+the last period of the day would be truncated by one-half or more, it is
+merged with the second-to-last period.
+
+An authority SHOULD publish its vote immediately at the start of each voting
+period (minus VoteSeconds+DistSeconds).  It does this by making it
+available at
+
+`http://<hostname>/tor/status-vote/next/authority.z`
+
+and sending it in an HTTP POST request to each other authority at the URL
+
+`http://<hostname>/tor/post/vote`
+
+If, at the start of the voting period, minus DistSeconds, an authority
+does not have a current statement from another authority, the first
+authority downloads the other's statement.
+
+Once an authority has a vote from another authority, it makes it available
+at
+
+`http://<hostname>/tor/status-vote/next/<fp>.z`
+
+where `<fp>` is the fingerprint of the other authority's identity key.
+And at
+
+`http://<hostname>/tor/status-vote/next/d/<d>.z`
+
+where `<d>` is the digest of the vote document.
+
+Also, once an authority receives a vote from another authority, it
+examines it for new descriptors and fetches them from that authority.
+This may be the only way for an authority to hear about relays that didn't
+publish their descriptor to all authorities, and, while it's too late
+for the authority to include relays in its current vote, it can include
+them in its next vote.  See section 3.6 below for details.