Rev 1.0 22/3/21
Rev 1.1 14/4/21
Rev 1.2 21/12/21
Rev 1.3 20/1/22

This is one of my personal "Cheat Sheets" which I've accumulated and built up
over the years to help me and other Technical People solve problems. And maybe
remind them or point out some tricks which they may have forgotten or not been
aware of.
I call them "Cheat Sheets" as they are intended to be very summarised hints
that someone might love to have in an exam :)

VoIP and CODECs CheatSheet
--------------------------
G.711 - 64 kbps
- Sample rate 64 kbit/s (8000 samples/sec x 8 Bits)
- Passes audio 300Hz-3.4kHz
- Telephone toll quality audio
- Typical algorithmic delay is 0.125 ms with no look ahead delay
- Can be used for fax over IP networks as defined in T.38 specification.
G.711u (PCMU) - (Often 3CX default)
- Popular in North America
- Waveform based compression. Reconstructs the signal without any speech models.
- Uncompressed linear CODEC
G.711a (PCMA)
- Popular in Europe and some Asia countries
- Waveform based compression. Reconstructs the signal without any speech models.
- Uncompressed linear CODEC
The basic difference between PCMU and PCMA are actual quantization, coding
steps, dynamic range and bit formats.
G.722 - High Fidelity voice
G.723 - 5.3-6.3 kbps - Low bandwidth CODEC
G.729 - 8 kbps - Low bandwidth CODEC
- 8 kbit/s
- Narrow band audio data compression algorithm using a frame length of 10 milliseconds.
G.729A
- Slightly lower voice quality than G.729
- Compatible with G.729
G.729B
- Extends G.729 with silence suppression. Not compatible with previous versions.
G.729AB
- Extends G.729A with silence suppression and is only compatible with G.729B
G.729D,F,H,I,C+
- 6.4 kbit/s
G.729E,G,H,I,C+
- 11.8 kbit/s

TPG VoIP SIP Servers for Software SIP Phones
3/12/09 Configuration worked:
Proxy: aphone5.tpg.com.au
Domain: tpg.com.au
Codec: G.729 No other Codec worked. Tried G.722,726,711u,711a
Codecs that worked around 2018
 aphone 1+2 G.723
 aphone 3-6 G.729
TPG 10/12/21 Rica says use G.729

STUN Servers
------------
stun.3cx.com
stun.internetcalls.com
 
Edward Jozis
"The Digital Doctor"
micronica.com.au
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