no SI (service interface) for the receiver side??

Hi experts,

I was going through the folllowing link:

http://www.****************/Tutorials/XI/WebService2RFC/page2.htm

Although I have tried to create the ESR and ID part exactly as it's in the scenerio but I couldnt understand why we havent created 2SI ..?

does it happens with every RFC scenerio?

secondly, I know between proxy and Rfc .proxy is preferred but why..?

Thanks in advance ...!