Business system/service Service without party: info needed

Question

Hi,
I am a newbie in XI world. I have a scenario of interfacing a 3rd party system to R/3 via XI. This system will dump a file to XI which needs to be converted to IDOC for R/3 use and later an outbound interface should send some data in a file format to this 3rd party system.
As per various blogs, I have managed to define business system and basid IR config. Since this a 2 way asyncronous interface,  I wanted to know
1> In XI, do I need to create a separate Buss System for 3rd Party sender interface( legacy->XI->R/3)
and a new Buss system for 3rd party Receiver interface.(R/3->Xi>Legacy). However in R/3 should I can create only one and assign the inbound/outbound IDOC partner profiles. ( But do the names of legacy systems in R/3 and XI have to be same)
2> What is the difference between Party and Service without Party( I saw these in ID). Do I need to define party for my interface scenario. If yes, How?
3> For testing, I wanted XI to pick files from my desktop and then post to R/3. As per various sdn threads, I realise, I need to give the IP of my PC and use Service without party. Since I am new in this area, I do not know how to define this serv-without party for my scenario. Any blogs or threads which define this would be very helpful.
Appreciate your help and time.
Helpful answers will be rewarded.
Thanks and regards
Shirin

Answer 1

Hi Shirin,
For 3rd party sysytems u can directly configure in ID under bussiness service
we will choose service without party when we are having A2A communication.
A2A means application to application communication, it is used when two systems in same landscape try to communicate with each other. Systems in same landscape means both the systems are belongs to same organization or a company.
Normally in A2A communication sender and receiver is inside one organization and developer have freedom to define communication rules .
refers to link
http://help.sap.com/saphelp_nw04s/helpdata/en/66/58934257a5c96ae10000000a155106/content.htm
we will choose service withparty when we are having B2B communication
B2B means Business to Business communication .It is used when there is exchange of information between two different Parties or companies or landscape.
When two applications in different companies communicates with each other we call it B2B Communication.
in case of B2B every party has it own rules which must be followed if we want to communicate between different organization.
refers to link
http://help.sap.com/saphelp_erp2004/helpdata/en/ca/efb540efe68631e10000000a1550b0/content.htm
communication party (party for short) represents a larger unit, which is involved in a collaborative process. Using a communication party, you generally address a company within a cross-company process.That means we use party only when we r using B2B communcation.for example communication of two diffrent organization who r having different landscape.
The matter of Party comes only when there are number of partners included in the environment. Thats usually happens in B2B systems. The services without party usually happens in normal A2A systems; were normal applications handle the message processing between systems and no multiple partners are interested in same data that are been handled.
/people/michal.krawczyk2/blog/2005/03/29/xi-error--unable-to-convert-the-sender-service-to-an-ale-logical-system
Business System : It is registered in SLD,We should have all the technical details to use
it, A business system is something that physicallu exists. generally for R/3 applications
we use this one.
Business Service : When we don't have all the technical details then we use the business
service, it is mostly used for B2B scenarios.
In ID objects tab in Business service is there, there right click and create the new business service, and fill the details like interface,...
BUSINESS SERVICE CREATION STEPS:
You can create the Business Service in ID itself.It is an abstract unit and it will act as Business System while exchanging the messages.In ID goto Service Without Party>Choose Business Service>Right Click and say as New>Give Servie Name as your Naming Conventions and choose u r configuration Scenario to adding the same> click on create>It will create the service and u can edit the service>u can find the tabs Receiver,Sender and etc--> Add ur Inbound/Outbound interfaces and corresponding Communication channels.
Regards,
Vinod.