In the RFC 4479 (A Data model For Presence)section below it is said that the Presentity can have multiple URIs.
But however as an End user i might not know about the protocol used by the device/client software i am using to access the service in
that case is it the responsibility of the client software to actually prepend and/or append the neccessary
protocol related identifiers to whatever User enters as his Login ID during authorization to use the service ?
3.1. Presentity URI
The
identifier for the presentity is a URI. For each unique
presentity in the network, there is one
or more presentity URIs. A
presentity may have multiple URIs because they are identified by both
a URI from the Presence (pres) scheme [12] and a protocol-specific
URI, such as a SIP URI [11] or an Extensible Messaging and Presence
Protocol Internationalized Resource Identifier (XMPP IRI) [13]. Or,
it can be because a user has several aliases in a domain, all of
which are equivalent identifiers for the presentity.
Kindly pardon me if it sounds naive.
Best Regards,
Vinay G. A.