49 seconds... how trusting! ;-) We use 25. Pete (it's true, but said tongue-in-cheek as I'm sure you have your data to show where the bulk of NATs expire) > On 11/06/2021, at 12:46 AM, Dovid Bender <dovid at telecurve.com> wrote: > > <snip> (we send SIP OPTIONS every 49 seconds) to ensure that the session stays alive.