Digigram IQOYA CALL Series, User Manual, Page: 73 / 77

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IQOYA *CALL - IQOYA *CALL/LE
User Manual v0.99
APPENDIX D: TYPICAL LATENCY VALUES
The back to back latency between two IQOYA*CALL devices depends on the selected audio format, the network
quality, and the enabled functionalities (backup, half/full duplex, FEC).
See the table underneath for maximum latency values in half­duplex, using neither failover configurations nor FEC,
with the jitter buffer size set to 0, and with an optimized network.
Audio Type Audio format Latency Description
PCM 24 bit
8ms
MPEG 256 kbps
53ms
Layer II, III
AAC­4 LC 128 kbps
74ms
AAC­4 HEv1 96 kbps
178ms
aka AAC­4 LC+SBR
AAC­4 HEv2 48 kbps
219ms
aka AAC­4 LC+SBR+PS
AAC­4 LD 160 kbps
38ms
AAC­4 ELD 160 kbps
32ms
Apt­X 24 bits
12ms
All measurements taken on stereo samples at 48 kHz
(Note: the lower the sample rate, the higher the latency)
Impact of the network on latency
Latency highly depends on the quality of the network. Network jitter and packets loss typically have a direct impact
on latency.
● Network jitter compensation is achieved by buffering audio data on the decoder. A good quality network
generally offers a low jitter, then requiring low buffering on the decoder, which means a low increase of
latency. But a network with a high jitter requires increasing the decoder buffering accordingly, leading to a
significant increase of latency.
● In case of packets loss on the network, it is necessary to enable an FEC, which allows recovering lost
packets thanks to redundant frames. FEC increases the latency.
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