Refer to the exhibit.
2015-02-02T19:46:31+01:00 collabedge tvcs: UTCTime=”2015-02-02 18:46:31,144” Module=”network.tcp” Level=”DEBUG”: Src-ip=”JabberPubIP” Src-port=”4211” Dst-ip=”VCS-E_IP” Dst-port=”5061” Detail=”TCP Connecting” 2015-02-02T19:46:31+01:00 collabedge tvcs: UTCTune=”2015-02-02 18:46:31,144” Module="network.tcp” Level=”DEBUG”: Src-ip=”JabberPubIP” Src-port=”4211” Dst-ip=“VCS-E_IP” Dst-port=”5061” Detail=”TCP Connection Established” 2015-02-02T19:46:49+01:00 collabedge tvcs: UTCTime=”2015-02-02 18:46:49,606” Module=”network.tcp” Level=”DEBUG”: Src-ip=”92.90.21.82” Src-port=”4211” Dst-ip=“VCS-E_IP” Dst-port=”5061” Detail=”TCP Connection Closed” Reason="Idle countdown expired”
While reviewing Expressway-E logs, an engineer encounters an idle countdown expired error that occurred when a Jabber client tried to register. There is a firewall in front of the Jabber client. Which cause of this error is true?

A.	SIP inspection is enabled on the firewall
B.	SIP inspection is disabled on the firewall
C.	UDP port 5061 is not allowed through the firewall
D.	TCP port 5061 is not allowed through the firewall