When A calls B. The INVITE goes through Kamailio. In the Kamalio 's log file, I see it say "bad Via", bad port. And it doesnot reply A with 100 Trying not forwarding INVITE to B.

The INVITE message (espcially the Via header) is OK. 

This problem sometimes happens. Do you know why ?

Please help. Thanks
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Khoa Pham
HCMC University of Science
Faculty of Information Technology