Sorry, the last reply comes from book of Monson-Haefel, it is wrong.
BP:
5.6.8 Multiple Ports on an Endpoint
When input messages destined for two different wsdl

orts at the same network endpoint are indistinguishable on the wire, it may not be possible to determine the wsdl

ort being invoked by them. This may cause interoperability problems. However, there may be situations (e.g., SOAP versioning, application versioning, conformance to different profiles) where it is desirable to locate more than one port on an endpoint; therefore, the Profile allows this.
R2711 A DESCRIPTION SHOULD NOT have more than one wsdl

ort with the same value for the location attribute of the soapbind:address element.