September 2008
Intermediate to advanced
550 pages
18h 10m
English
Content preview from VoIP Voice and Fax Signal Processing
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13.11 DEPLOYMENT TESTS
In actual deployment, several inter-op and voice quality tests are conducted, but the scope of testing is limited. Required additional tests are supplemented with laboratory test setup. Several voice ports from the deployment are also looped back to the laboratory test setup, and deployment performance is evaluated with several laboratory tests. It is also common practice to use several listening tests with various call combinations. Some popular options for voice quality tests are as follows:
- Multiple listeners in noisy and noise-free environment.
- Echo canceller tests through listening and measurements with Sage 960B.
- Testing using instruments like Opticom P.563 [URL (Opticom-P563)], which is based on a single-ended voice quality measure [www.opticom.de] that measures one-way voice without calling for reference speech signal.
- Voice quality monitoring using VQmon, Real-Time Transport Control Protocol-Extended Report (RTCP-XR), and E-model, which conduct voice quality monitoring as a remote logging operation from the servers.
- PESQ–MOS measurements by looping the calls to the laboratory or using distributed test nodes with instruments like Malden Electronics MultiDSLA.
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