[Serusers] SER proxy and Asterisk features

I am involved in a new deployment of the famous SER and Asterisk tandem. The goal is to use SER as a SIP proxy (what it is) and Asterisk as an IP-PBX (connection to PSTN and voicemail). We plan to make extensive use of WiFi phones. I begin to have "some" understanding of the interplay between SER and Asterisk, especially when it comes to handle calls to/from the PSTN as well as transfers to voicemail. On the other hand, I keep stumbling on the following question: Besides handling voicemail and interconnection to PSTN, Asterisk offers many of the traditional PBX features (for example CallWaiting activated by hookflash or *64 for DoNotDisturb). For SIP to SIP calls handled solely by SER (unless I am mistaken), how are these features invoked (or activated)? What kind of messaging goes on when hookflash or *xx is activated on the phone? What are the respective roles and responsibilities of SER and Asterisk in handling such messaging? Regards Yves DeSerres (ydeserres(a)raris.net) Raris Communications