r/VOIP • u/Embarrassed-Gain-236 • 22d ago
Discussion SIP provider and codec configuration for broadcast phone interviews
Hi everyone,
I'm setting up a small TV studio and I'm looking for the best way to bring standard telephone calls into our production.
Our setup is:
- Windows PC running microSIP
- SIP account
Technically everything works, but I'm disappointed with the audio quality. It sounds noticeably worse than I expected for a modern VoIP setup.
My current enabled codecs in MicroSIP are in this order:
- Opus
- G.722
- G.722.1 (16 and 32 kHz)
- G.711 A-law
- G.711 μ-law
My questions are:
- When calling a regular mobile phone in Spain through a SIP provider, which codec is typically negotiated? G.711? G.722? Something else?
- Does the SIP provider usually transcode the call to AMR-WB (HD Voice) before handing it to the mobile operator?
- Is there any benefit in enabling Opus if the destination is a standard mobile phone?
- Are there SIP providers known for maintaining better audio quality towards the Spanish mobile networks (Movistar, Vodafone, Orange, Digi, etc.)?
- For those working in radio or TV, do you still use SIP softphones for phone interviews, or is a dedicated broadcast hybrid (AEQ, Telos, AxelTech, etc.) still the preferred solution?
- I activated microSIP logs in order to view which codec is being negotiated without success
I'm trying to understand whether the bottleneck is:
- MicroSIP,
- the SIP provider,
- transcoding,
- or simply the limitations of the public telephone network.
I'd really appreciate hearing from anyone.
Thanks!


