Hi Anusha,
External ID as associate with Doctype while extracting sender ID and receiver ID for incoming Document.
We have to associate external ID in doctype extraction while defining Doctype, based on external id and corresponding value it will recognize Sender/Receiver partner profile in TN.
We have various build in external id like DUNS, user defined1, EAN, mutually defined etc, and also we can create custom external id also as per business requirement.
Thanks,
Arun
#B2B-Integration#webMethods#Integration-Server-and-ESB