CFN is a confusion message based on ISDN. Generally, CFN is generated as a result of a protocol error. The generated CFN will encourage the node (in your case the MSC) to re-send the message, e.g. IAM.
VBR/ Wallis Dudhnath
vivek - 15th March 2015 (06:01 GMT)
Me too facing same issue.same doudt.any idea on this for anyone.post this message call failing as cv-127 after acm
Mahmoud - 29th October 2011 (12:47 GMT)
It depend on your counters.
Realy it's not service affecting, but load exrta unused load for signaling nd also increase call establishment time.
You can follow up the case with peer side and find mismatch between you MSC and peer side, (Some requested parameter in IAM are not in same configuration)
Neeraj Kumar - 24th October 2011 (10:50 GMT)
when I am sending IAM message, every time I m receving CFN message brfore ACM. On this connectivity, I have less CSR and ASR issue. Please let me know is that CFN message can effect on CSR and ASR..