表一：以MOS級別判斷VoIP服務品質標準
|
| 級別 | 評分 | 用戶滿意度 |
| 優 | 4~5 | 很好，聽的清楚，延遲很小，溝通順暢。 |
| 良 | 3.5~4 | 稍差，聽的清楚，延遲小，交流尚順暢，有點雜音。 |
| 中 | 3~3.5 | 還可以，聽不太清楚，有一定延遲，可以交流。 |
| 差 | 1.5~3 | 勉強，聽不太清楚，延遲較大，溝通需重複多次。 |
| 劣 | 0~1.5 | 極差，聽不懂，延遲大，溝通不順暢 |
表二：封包漏失率和抖動對網路的影響
|
| 網路等級 | 封包漏失率 | 抖動 |
| 良好 | 0% | 1ms |
| 一般 | 1% | 20ms |
| 差 | 5% | 60ms |
表三：延遲對語音品質的影響
|
| 網路等級 | 封包延遲時間 | 使用者感受 |
| 良好 | <=150ms | 最好，為大多數用戶應用程式所接受 |
| 尚可 | 150~250ms | 可接受，部分用戶感受到品質有些許影響 |
| 一般 | 250~400ms | 大多數用戶明顯感受到品質的降低 |
| 差 | >=400ms | 大多數用戶不能接受 |
Spirent Test Case:
1. VoIP Call Setup Rate
Test will determine the maximum setup rate for Voice over IP(VoIP) calls that can be estalished through a DUT.
2. Converged VoIP and Data test
Test the quality of VoIP calls as data and media is introduced to the same network.
3. VoIP test during DoS attacks
Test will determine the effect of Denial of Service attacks have on Voice over IP(VoIP) calls through a DUT.
4. VoIP Performance with NAT
Test will determine the maximum mumber of Voice over IP(VoIP) calls that can be established through a DUT while NAT is enabled.
5. VoIP Performance Over IPsec
Test will determine the maximum number of IPsec VPNs that can be established through a DUT before call setup degradation
6. Maximum Concurrent VoIP Calls
Test will determine the maximum number of Voice of IP(VoIP)calls that can be established through a DUT.
Integration Test Case:
1. VoIP pass through VPN.
