Difference between revisions of "VoIP: Memperhitungkan Kualitas Suara"
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Persepsi pengguna di representasikan dalam nilai dari [[MOS]] dan [[R Factor]] adalah sebagai berikut | Persepsi pengguna di representasikan dalam nilai dari [[MOS]] dan [[R Factor]] adalah sebagai berikut | ||
| − | |||
{| border="1" cellpadding=2 style="border-collapse: collapse" | {| border="1" cellpadding=2 style="border-collapse: collapse" | ||
! Opini Pengguna | ! Opini Pengguna | ||
| − | ! R Factor | + | ! [[R Factor]] |
| − | ! MOS Score | + | ! [[MOS]] Score |
|- | |- | ||
| Maximum yang di dapat G.711 | | Maximum yang di dapat G.711 | ||
| Line 41: | Line 40: | ||
|} | |} | ||
| + | [[Image:Voiptroubleshootercom.jpg|right|200px|thumb]] | ||
[[MOS]] dapat di lihat di http://www.voiptroubleshooter.com/diagnosis/emodel.html | [[MOS]] dapat di lihat di http://www.voiptroubleshooter.com/diagnosis/emodel.html | ||
| − | |||
Cuplikan hasil perhitungan [[MOS]] dan [[R Factor]] adalah sebagai berikut | Cuplikan hasil perhitungan [[MOS]] dan [[R Factor]] adalah sebagai berikut | ||
| − | Codec | + | {| border="1" cellpadding=2 style="border-collapse: collapse" |
| − | Frame | + | ! [[Codec]] |
| − | Packet Loss | + | ! [[Frame]] |
| − | MOS | + | ! [[Packet Loss]] |
| − | R Factor | + | ! [[MOS]] |
| − | Kbps | + | ! [[R Factor]] |
| − | G.711 | + | ! [[Kbps]] |
| − | 20ms | + | |- |
| − | 0% | + | | G.711 |
| − | 4.4 | + | | 20ms |
| − | 93 | + | | 0% |
| − | 80.8 | + | | 4.4 |
| − | G.723 5kbps | + | | 93 |
| − | 20ms | + | | 80.8 |
| − | 0% | + | |- |
| − | 3.8 | + | | G.723 5kbps |
| − | 74 | + | | 20ms |
| − | 16.5 | + | | 0% |
| − | G.723 6kbps | + | | 3.8 |
| − | 20ms | + | | 74 |
| − | 0% | + | | 16.5 |
| − | 4.0 | + | |- |
| − | 78 | + | | G.723 6kbps |
| − | 17.5 | + | | 20ms |
| − | G.729 | + | | 0% |
| − | 20ms | + | | 4.0 |
| − | 0% | + | | 78 |
| − | 4.1 | + | | 17.5 |
| − | 83 | + | |- |
| − | 24.8 | + | | G.729 |
| + | | 20ms | ||
| + | | 0% | ||
| + | | 4.1 | ||
| + | | 83 | ||
| + | | 24.8 | ||
| + | |} | ||
| − | + | ==MOS vs. Packet Loss== | |
| − | + | Efek dari [[packet loss]] di jaringan karena berbagai hal akan menyebabkan [[MOS]] dan [[R Factor]] turun drastis sesudah 5% packet loss. | |
| − | |||
| − | |||
| − | MOS | ||
| − | R Factor | ||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | 5% | ||
| − | |||
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| − | |||
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| − | |||
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| − | + | {| border="1" cellpadding=2 style="border-collapse: collapse" | |
| + | ! [[Codec]] | ||
| + | ! [[Frame]] | ||
| + | ! [[Packet Loss]] | ||
| + | ! [[MOS]] | ||
| + | ! [[R Factor]] | ||
| + | ! [[Kbps]] | ||
| + | |- | ||
| + | | G.729 | ||
| + | | 20ms | ||
| + | | 0% | ||
| + | | 4.1 | ||
| + | | 83 | ||
| + | | 24.8 | ||
| + | |- | ||
| + | | G.729 | ||
| + | | 20ms | ||
| + | | 5% | ||
| + | | 3.3 | ||
| + | | 64 | ||
| + | | 24.8 | ||
| + | |- | ||
| + | | G.729 | ||
| + | | 20ms | ||
| + | | 10% | ||
| + | | 2.7 | ||
| + | | 52 | ||
| + | | 24.8 | ||
| + | |- | ||
| + | | G.729 | ||
| + | | 20ms | ||
| + | | 20% | ||
| + | | 1.9 | ||
| + | | 37 | ||
| + | | 24.8 | ||
| + | |} | ||
| − | + | ==MOS vs Frame Size== | |
| − | Frame | ||
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| + | Panjang payload / [[frame size]] suara yang semakin panjang akan menurunkan [[bandwidth]] yang dibutuhkan karena overhead [[protocol]] menjadi semakin rendah. [[Frame size]] yang normal digunakan adalah 20ms suara dengan [[bandwidth]] sekitar 25Kbps. | ||
| + | {| border="1" cellpadding=2 style="border-collapse: collapse" | ||
| + | ! [[Codec]] | ||
| + | ! [[Frame]] | ||
| + | ! [[Packet Loss]] | ||
| + | ! [[MOS]] | ||
| + | ! [[R Factor]] | ||
| + | ! [[Kbps]] | ||
| + | |- | ||
| + | | G.729 | ||
| + | | 2.5ms | ||
| + | | 0% | ||
| + | | 4.1 | ||
| + | | 83 | ||
| + | | 41.6 | ||
| + | |- | ||
| + | | G.729 | ||
| + | | 5ms | ||
| + | | 0% | ||
| + | | 4.1 | ||
| + | | 83 | ||
| + | | 41.6 | ||
| + | |- | ||
| + | | G.729 | ||
| + | | 10ms | ||
| + | | 0% | ||
| + | | 4.1 | ||
| + | | 83 | ||
| + | | 41.6 | ||
| + | |- | ||
| + | | G.729 | ||
| + | | 20ms | ||
| + | | 0% | ||
| + | | 4.1 | ||
| + | | 83 | ||
| + | | 24.8 | ||
| + | |- | ||
| + | | G.729 | ||
| + | | 30ms | ||
| + | | 0% | ||
| + | | 4.1 | ||
| + | | 83 | ||
| + | | 19.2 | ||
| + | |} | ||
==Referensi== | ==Referensi== | ||
| Line 159: | Line 179: | ||
* [[VoIP: Bandwidth Internet Telepon]] | * [[VoIP: Bandwidth Internet Telepon]] | ||
* [[VoIP]] | * [[VoIP]] | ||
| + | |||
| + | |||
| + | [[Category: VoIP]] | ||
| + | [[Category: Internet Telepon]] | ||
Latest revision as of 15:31, 10 May 2010
Kualitas suara menjadi penting, karena ini akan sangat mempengaruhi penerimaan suara di lawan bicara kita. Satuan kualitas suara yang digunakan biasa di sebut Mean Opinion Score (MOS) dan R Factor. Kualias suara sangat tergantung pada dua (2) hal, yaitu,
- Teknik kompresi yang digunakan.
- Banyaknya packet loss di jaringan.
Persepsi pengguna di representasikan dalam nilai dari MOS dan R Factor adalah sebagai berikut
| Opini Pengguna | R Factor | MOS Score |
|---|---|---|
| Maximum yang di dapat G.711 | 93 | 4.4 |
| Sangat memuaskan | 90-100 | 4.3-5.0 |
| Memuaskan | 80-90 | 4.0-4.3 |
| Baik | 70-80 | 3.6-4.0 |
| Banyak yang tidak puas | 60-70 | 3.1-3.6 |
| Buruk | 50-60 | 2.6-3.1 |
| Tidak direkomendasikan | 0 – 50 | 1.0-2.6 |
MOS dapat di lihat di http://www.voiptroubleshooter.com/diagnosis/emodel.html
Cuplikan hasil perhitungan MOS dan R Factor adalah sebagai berikut
| Codec | Frame | Packet Loss | MOS | R Factor | Kbps |
|---|---|---|---|---|---|
| G.711 | 20ms | 0% | 4.4 | 93 | 80.8 |
| G.723 5kbps | 20ms | 0% | 3.8 | 74 | 16.5 |
| G.723 6kbps | 20ms | 0% | 4.0 | 78 | 17.5 |
| G.729 | 20ms | 0% | 4.1 | 83 | 24.8 |
MOS vs. Packet Loss
Efek dari packet loss di jaringan karena berbagai hal akan menyebabkan MOS dan R Factor turun drastis sesudah 5% packet loss.
| Codec | Frame | Packet Loss | MOS | R Factor | Kbps |
|---|---|---|---|---|---|
| G.729 | 20ms | 0% | 4.1 | 83 | 24.8 |
| G.729 | 20ms | 5% | 3.3 | 64 | 24.8 |
| G.729 | 20ms | 10% | 2.7 | 52 | 24.8 |
| G.729 | 20ms | 20% | 1.9 | 37 | 24.8 |
MOS vs Frame Size
Panjang payload / frame size suara yang semakin panjang akan menurunkan bandwidth yang dibutuhkan karena overhead protocol menjadi semakin rendah. Frame size yang normal digunakan adalah 20ms suara dengan bandwidth sekitar 25Kbps.
| Codec | Frame | Packet Loss | MOS | R Factor | Kbps |
|---|---|---|---|---|---|
| G.729 | 2.5ms | 0% | 4.1 | 83 | 41.6 |
| G.729 | 5ms | 0% | 4.1 | 83 | 41.6 |
| G.729 | 10ms | 0% | 4.1 | 83 | 41.6 |
| G.729 | 20ms | 0% | 4.1 | 83 | 24.8 |
| G.729 | 30ms | 0% | 4.1 | 83 | 19.2 |