sergey-safarov left a comment (kamailio/kamailio#4290)
Let me rephrase the issue description. Please start Kamailio with the config file ``` route{ forward(); } ``` And send an OPTIONS message using the command ``` cat options-extra.txt | nc -u 192.168.1.1 5060 ``` Where a private IP address needs to be replaced with the IP address of Kamailio on the network interface.
In this case, Kamailio will forward the OPTIONS message towards `158.51.225.1`. If you check the forwarded message, you will see the `trailer` bytes in the UDP frame.
If I understand the RFC requirements, `trailer` should be `discarded`.
In the case of message-oriented transports (such as UDP), if the
message has a Content-Length header field, the message body is assumed to contain that many bytes. If there are additional bytes in the transport packet beyond the end of the body, they MUST be discarded.
As I understand it, Kamailio does not meet these requirements.