SIP代表会话发起协议， VoIP代表IP 语音区域单元，这些技术用于批准任何类型的网络通信。但是，VoIP(IP 语音)单独用于 IP 电信，而 SIP(会话发起协议)是处理传输交换的协议。另外具体来说，SIP(Session Initiation Protocol)信令协议是由于标准化了VoIP(Voice over IP)或IP电信。
会话发起协议用于排列网络电话呼叫、视频会议和替代传输连接。另一方面，语音 IP 用于通过信息网络传输语音流量。
让我们看看下面以表格形式给出的 SIP 和 VoIP 协议之间的区别：
| S.NO | SIP | VOIP |
|---|---|---|
| 1. | SIP stands for Session Initiation Protocol. | Whereas VoIP stands for Voice over IP. |
| 2. | SIP can handle all types of media. | While it can handles voice calls as well as messages. |
| 3. | SIP is more flexible. | While it is a little bit flexible. |
| 4. | SIP is not depend any other device. | But it depend on that devices which provide internet. |
| 5. | It is protocol of application layer. | While it is Layer 3 network protocol. |
| 6. | It is related with signalling protocol to manipulate the technologies. | Whereas it is related with Separate and severally noticeable technology. |
| 7. | It is compatible with internet. | While it is also compatible with internet. |
| 8. | SIP uses severally systems for handling completely different operations. | While it uses only particular system for handling entire operations. |