Login for Updatable Subscriptions
If you selected Replicate on the Updatable Subscriptions page of this wizard, you must specify an account at the Subscriber under which connections to the Publisher are made for immediate updating subscriptions. Connections are used by the triggers that fire at the Subscriber and propagate changes to the Publisher. This account is required even if you selected Queue changes and commit when possible on the Updatable Subscriptions page, because by default the New Subscription Wizard configures queued updating with the ability to switch to immediate updating if required.
The account specified for the connection should only be granted permission to insert, update, and delete data on the views that replication creates in the publication database; it should not be given any additional permissions. Grant permissions on views in the publication database that are named in the form syncobj_<HexadecimalNumber> to the account you configured at each Subscriber.
There are three options available for the type of connection:
A linked server or remote server that you have already defined.
A linked server that replication creates; the connection is made with the credentials you specify in this wizard.
A linked server that replication creates; the connection is made with the credentials of the user making the change at the Subscriber.
The first two options can be specified in this wizard. The last option can only be specified using sp_link_publication (Transact-SQL); specify a value of 1 for the parameter @security_mode.