[abbe_k]

How do you tell if it's voip or not? A lot of phone operators use voip for calls. So choosing the default phone app doesn't necessarily mean that you are not using voip. And the phone operators infrastructure for voip is probably way ahead of most other call apps.

[pfranz]

> A lot of phone operators use voip for calls.

I think the problem is that with "analogue" each jump can use a hodgepodge of their own voip going from Analog -> Digital -> Analog. So you can get multiple, lossy compressions with varying settings multiplied together. With user-initiated voip, it's a single compression over the whole connection. So it could be better than user-initiated voip, or a lot worse.

At least that's my laymen's understanding of legacy phone systems.

[zAy0LfpBZLC8mAC]

There is no such thing as analog telephony anymore, and there hasn't been for a long time. While you might still have analog local loops, the network has been completely digital for a long time, be it ISDN or VoIP, and VoIP is perfectly capable of transmitting ISDN voice data without recoding.

[userbinator]

I think what might be being referred to as "analog telephony" is actually the "original digital" system using 64Kbps "uncompressed" PCM, vs. VoIP compressed audio at much lower bitrates. It's like the difference between CD and MP3.

[zAy0LfpBZLC8mAC]

I would be very surprised if any telco were using any sort of compression internally (other than G.711, obviously). 64 kb/s with RTP/IP framing overhead is about 100 kb/s, that's just not a lot of bandwidth anymore that it would be worth installing hardware to do de-/compression. Even a gigabit link can carry ~ 10000 such calls--that's a drop in the bucket compared to the internet needs of the many more than 10000 subscribers that you need to ever have 10000 concurrent calls (probably more in the range hundreds of gigabits, possibly terabits).

[abbe_k]

I'm pretty sure that most operators either use analogue or digital end to end, no mix.

VoLTE (Voice over LTE) have some other advantages over other calling applications. VoLTE is most likely on a very high QCI (priority), which means it probably has less delay and less packet loss than other traffic. VoLTE also often uses header compression over the air which means the packets gets a lot smaller and therefore also reduces packet loss. I don't think VoLTE usually have very high bitrate though, maybe around 10kbit/s. This is one area where other apps could be a lot better.

EDIT: I am of course only speaking about mobile calls. For landlines I agree that other applications provide better quality.

[Rjevski]

The issue is that VoLTE only works for calls made to the same carrier's subscribers, as soon as you call someone on another carrier it will go through a shitty interconnect with a bad codec (usually a variant of G711 which is a joke in 2017).