問題文
A party on hold is hearing a stream that a music server set up after a REFER from the holding party. In the service example, how does the holding party bring that party back off hold?
選択肢
- With a REFER that names the music server a second time, since the party has to be taken off the stream the same way that it had been brought to it.
- With an INVITE that names the dialog toward that music server, since the dialog that it had held with that party was brought to an end once the music took over.
- With a further INVITE that names the dialog it had held, since that dialog stayed in place underneath the stream that the music server had brought in.
- With an UPDATE that names the dialog it had held, since the direction of that stream was the single thing the hold had altered before the music server came in.