cXML request - unknown attributes

Question

I received one document from the supplier that describes how I can send the cXML request to purchase orders from their website. They send me an example, but I'm not sure do we need to make some sort of connection, because here we have :

Credential domain
Identity
SharedSecret

Is this something common in XML requests, and do I need to contact them to set up a connection, Im not sure, and I don't wanna be stupid because they already send me documentation but this part is not so good explained, any help?

<Header>
     <From>
         <Credential domain="AribaNetworkUserId">
             <Identity>admin@acme.com</Identity>
         </Credential>
     </From>
     <To>
         <Credential domain="DUNS">
             <Identity>114315195</Identity>
         </Credential>
     </To>
     <Sender>
         <Credential domain="AribaNetworkUserId">
             <Identity>sysadmin@ariba.com</Identity>
             <SharedSecret>abracadabra</SharedSecret>
         </Credential>
         <UserAgent>Network Hub V1.1</UserAgent>
     </Sender>
</Header>

Answer 1

TL;DR

Credential contains an Identity element and optionally a SharedSecret element. The Identity element states who the Credential represents, while the optional authentication elements verify the identity of the party.

Detailed Review

The Header element contains addressing and authentication information.

The From and To elements are synonymous with From and To in SMTP mail messages; they are the logical source and destination of the messages. You will match them against the Ariba Network Account which can be retrieved by the Ariba Network ID / AN User Id or Duns ID. Usually the From will be your AN Id (you're supposed to know your account Id) and To can be AN Id or duns (for example of catalog purchase the supplier would have put its duns Id in the catalog)

Credential specifies the type of credential. This attribute allows documents to contain multiple types of credentials for multiple authentication domains. For messages sent on Ariba Network, for instance, the domain can be AribaNetworkUserId to indicate an email address, DUNS for a D-U-N-S number, or NetworkId for a preassigned ID.

Sender is the party that opens the HTTP connection and sends the cXML document.

Sender contains the Credential element, which allows the receiving party to authenticate the sending party. This credential allows strong authentication without requiring a public-key end-to-end digital certificate infrastructure. Only a user name and password need to be issued by the receiving party to allow the sending party to perform Requests.

When the document is initially sent, Sender and From are the same, However, if the cXML document travels through network hubs, the Sender element changes to indicate current sending party.