ISP和SIP的区别

Internet Service Provider 提供网络服务的公司，包括了拨接服务，提供专线连线，或是作一些网络上服务（制作Homepage，架设网络...）等等的公司。
(Session Initiation Protocol) Used for setting up communications sessions on the Internet, such as telephony, presence, events notification and instant messaging. The protocol initiates call setup, routing, authentication and other feature messages to endpoints within an IP domain.