Use of Identifiers in Communication channel definition

Question

Hi all,
I have read the help.sap links about identifiers and their areas of usage. But still having some doubts.
I have got an idea about its usage in value mapping. I would like to know how the identifier is used by the communication channels in inbound and outbound processing.
The link says that <i>If a message from an external party contains an identifier for a company in the message header, the identifier is mapped to the name of the internal party</i>
But I thought the message headers are created only in XI after picking up the message content from the sender.  Can someone please explain me.

Answer 1

Hi Aarthi, 
In the communication channel, you can then specify the identifier to be used as the ID for the communication party.  In the identifiers tab of the communication channel screen, information wil be entered to help the system identify the sender as customer & not a logical system.
The available identifiers are specified in the communication party as alternative identifiers.
A 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. 
You can assign a communication party one or more services to address it as the sender or receiver of messages
Identifiers are used to identify objects uniquely.
An identifier comprises the following:
·Agency
Defines the identification scheme and issues names for the objects to be identified.
·Identification Scheme (or ‘scheme’ for short)
Constitutes the reference framework within which objects are uniquely identified by names.
·Name/Value
A name or value that identifies the object within the given identification scheme.
An object can only be uniquely identified when all three have been specified.
A person can be identified in many different ways, for example, by their customer number at a mail order company, or their name or employee number at their place of work. To be able to identify a person uniquely, it is not sufficient to just know the customer number, for example, you must know that this number is a customer number. Only once the frame of reference (the identification scheme Customer Number) is also known can a person be identified uniquely (by using the number).
In the example, the agency Mail Order Company manages the identification scheme Customer Number. Different customers are issued unique names (customer numbers) within this scheme.
Use
Identifiers are used in the following areas of SAP Exchange Infrastructure.
·To identify communication parties
·In value mappings.
·To set a receiver in the proxy runtime
These r the web-sites which give a detailed description about identifiers :
http://help.sap.com/saphelp_nw04/helpdata/en/2b/d5653fd1d3b81ae10000000a114084/content.htm
http://help.sap.com/saphelp_nw04/helpdata/en/81/104bb1fbab254c8644877c7f856bbf/content.htm
http://help.sap.com/saphelp_nw04/helpdata/en/9f/36bf393a06ec4fbd079233c3fcdea2/content.htm( This web-site gives all & detailed information regarding identifiers usage)
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cheers,
gyanaraj