Wireshark-users: [Wireshark-users] why my wireshark can't capture SIP packet.

From: 梁泰伦 <liangtailun@xxxxxxxxx>
Date: Sun, 2 May 2010 23:28:59 +0800
when I try to use wireshark to capture SIP packet about two aplication that base on JAIN-SIP in windows.I can't find some packet associate with SIP or other associated informantion.
But I can capture other packet like tcp udp and so on.How can I do to capture sip message?
my English speaking is poor.
thanks for your help.