SipWarpCodecs
A codec is how the voice is packed up to cross the internet. SipWarp does not switch codecs based on who you dialed. You choose, because you are the connecting caller.
When you place the call, SipWarp sends the Enabled list from top to bottom. The service that answers can only use a codec on that list. It takes the highest one it supports. So the order you set is the choice that matters.
Leave them in this order:
| Order | Codec | Use it for |
|---|---|---|
| 1 | G.711u | Phone-network calls in the US and Canada. voip.ms uses this toward a cell phone. This is the one most calls will pick, because it is first and almost every provider supports it. |
| 2 | G.711A | The same kind of call in Europe. |
| 3 | G.722 | A wider, clearer sound when the other end is a SIP phone or a provider that supports it. |
| 4 | Opus | The codec modern SIP apps prefer when both ends are on the internet. A cell call still stays on G.711u while that is first. |
G.711 is not new. Phone networks have used it for decades. G.711u and G.711A are the same quality. The letter is the region.
Speex, GSM, iLBC, and LPCM can sit in Available. They are old, narrow, or uncompressed. Leave them off unless a provider tells you it requires one.
The checkboxes under the list
- VAD stops sending audio when you are quiet. It saves a little bandwidth and can chop the first syllable of a word. Leave it off.
- Echo cancellation removes the other person's voice from your microphone. Leave it on.
- Opus stereo is only for Opus, and only if you truly want two-channel audio. It also turns echo cancellation off. Leave it off for a headset or a call to a cell phone.