How much background traffic would you expect between a phone and the server?

[greychain]

I have a customer that has collected statistics showing the phone generates 5MB/minute in one direction and
about half the other way. So that's about 11GB/month is this a normal amount of traffic?

It's 3CX Debian V16, the phones are Yealink T21 P2 and the phone is on a separate network segment to the server.

 

[leejor]

A lot will depend on whether it is only voice traffic, or the sets are using things such as BLF keys. Are the set to using STUN, or is there an SBC, so the local call traffic stays local? What type of Codec is being used? How many calls are the sets taking? A lot of variables, that mean no two set-ups are going to be the same. I cannot recall seeing stats on "total" traffic, from a site simply based on the number of sets.

There's this... https://www.3cx.com/blog/docs/bandwidth-utilised-for-voip/