The Camel SIP component depends on org.apache.servicemix.specs / org.apache.servicemix.specs.jain-sip-api-1.2
That JAR depends on javax.sip / jain-sip-api
The JAIN sip-api classes are not under an Apache compatible free software license.
The related jain-sip-ri classes (the runtime implementation) are under an Apache compatible license so this bug doesn't concern them.
The solution is to change the dependency to org.opentelecoms.sip / sip-api or one of the other implementations.