Dear all, Today we had an attack. One of our clients lost password to his SIP account. So with this password attackers made calls on our client's behalf to very expensive destinations. We have Opensips as a border controller and Freeswitch as a Softswitch. This phone was confugured for 1 concurrent line using module limit of FS. Howerver they somehow managed to make several concurrent calls per one account. On CDR's we found that there was Attended transfer. Does anybody knows what kind of attack was that and how I can protect us against this? Is it sip refer attack when attacker set REFERED BY HEADER? When I check if limit works whith a sipphone, I see that it worked 100%. Thanks in advance -- Kamil Nigmatullin Tel: 77272323748 mob: 7 (707) 2517003 Skype: kamil.nigmatullin