Tag Archives: 400 bad request

Outbound PSTN calls fail from Lync Enterprise Voice enabled Resource Mailbox

During a recent Lync Server 2010 to 2013 migration project, it was reported that a few Exchange resource mailbox accounts enabled for Lync Enterprise Voice were unable to make outbound PSTN calls. However inbound and Lync to Lync calls were successful. Reviewing the Lync client logs from these conference room accounts showed: SIP/2.0 400 Bad… Read More »