SIP 协议部署
基于 Trillium SIP 协议栈可以开发不同服务，包括 呼叫控制（call control），注册管理服务（registry management services），和 定位服务（location services）。 下面还是用英文说明这3类服务。
Call control on a UA initiates and terminates a call, including signalling and meida. It is reponsible for resource reservation, media management, authentication, security, encryption, and providing supplementry services. On SIP Gateways, it can support an interworking function to other kinds of networking protocols. On a proxy server, it additionally controls call routing and call state maintenances for the server controlling a firewall.
The registry management function is reponsible for registering all physical users at a SIP UA with the registrar server. At a registrar server, registry maintains the database of the endpoints ( or users logged on the endpoints ) and reponds to all address resolution requests for these users.
Location services provide user location services to the SIP layer. It can do this by either:
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Calling on the database maintained by the registry management function Calling on one or more global location services ( finger, LDAP, rwhois, multicast-based protocols, or operating system-dependent mechanisms ) whether resident on the local server or on one or more remote location servers
SIP 编程模型
SIP 编程开发需要两个协议栈，SIP 和 TCP/UDP 协议栈
用户可以利用 SIP 协议栈编写终端接口应用程序、网关应用程序、防火墙，资源存储，认证以及及时消息应用程序，而 TCP/UDP 提供下层同操作系统的套接字接口。