Ip Telephone Voice Performance; Ip Codes; Coding Rate; Objective Evaluation On Voice - Zte ZXMSG 5200 Technical Manual

ZXMSG 5200 (V2.0) Technical Manual

IP Telephone Voice Performance

IP Codes

The ZXMSG 5200 service processing unit supports the following codes:
G.711 (5ms/10ms/20ms Ethernet packets)
G.729a (10ms/20ms Ethernet packets)
G.723.1 (30ms Ethernet packets)

Coding Rate

Different coding algorithms need gateways to have different coding rates:
For G.729a, the coding rate is required to be less than 18 kbps.
For G.723.1 (5.3), the coding rate is required to be less than 12 kbps;
for G.723.1 (6.3) less than 15 kbps.

Objective Evaluation on Voice

In a good network condition: PSQM mean value is less than 1.5.
Poor network condition (packet loss ratio = 1%, network jitter = 20
ms, delay = 100 ms): PSQM mean value is less than 1.8.
Worst network condition (packet loss ratio = 5%, network jitter = 60
ms, delay = 400 ms): PSQM mean value is less than 2.0.

Subjective Evaluation on Voice

In a good network condition: MOS > 4.0
Poor network condition (packet loss ratio = 1%, network jitter = 20
ms, delay = 100 ms): MOS > 3.5
Worst network condition (packet loss ratio = 5%, network jitter = 60
ms, delay = 400 ms): MOS > 3.0

Delay Indices

The delay of IP telephone can mean coding/decoding delay, input buffer
delay at the receiving end and internal queue delay.
G.729 delay is less than 150 ms.
G.723.1 delay is less than 200 ms.
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