5.6.4. The Election Process

The election is performed on the responder. The responder compares the Origin-Host received in the CER with its own Origin-Host as two streams of octets. If the local Origin-Host lexicographically succeeds the received Origin-Host, a Win-Election event is issued locally. Diameter identities are in ASCII form; therefore, the lexical comparison is consistent with DNS case insensitivity, where octets that fall in the ASCII range 'a' through 'z' MUST compare equally to their uppercase counterparts between 'A' and 'Z'. See Appendix D for interactions between the Diameter protocol and Internationalized Domain Name (IDNs).

The winner of the election MUST close the connection it initiated. Historically, maintaining the responder side of a connection was more efficient than maintaining the initiator side. However, current practices makes this distinction irrelevant.