Hi Just wondering if these could be implemented in the soft-phone offering (SIP T1, T2 & T4). We have a couple of customers who are bordering on 500ms round-trip time, and one or two that are in the region of ~950ms. The SIP re-transmission on calling is causing a number of problems when they make calls. As far as I know, no softphone implements customisable SIP retransmission timers. We recommend 3CXPhone and, have a pre-configured link, as it's by far the best soft-phone for Windows. However, I've tried 3CXPhone, X-Lite, Zoiper, SJPhone, ExpressTalk and, none of these allow you to change T1. I'm not sure how many other people would think this would be a welcome addition but, I think that for some problematic internet connections, it's a life-saver and would put 3CX phone even further ahead of the competition!! Kind Regards Daryl PS - I know it's community led, with no tech support but, if any developers do read this, please do consider it!!