Pairing a network user to an SIP ID

Hello all, I have successfully implemented opensips with freeradius as AAA server, what I'd like to know is whether it's possible to assign a network user of freeradius to an SIP ID which can be used for opensips. The network is using freeradius as authenticator, after the user have been authenticated and authorized to use the network, then said user will be assigned an SIP ID to use for VoIP calls via opensips. The authentication and authorization of the SIP ID also done in freeradius too. Is it possible to do it in freeradius? Thank you for the answers.