The question is not quite clear to me. In principle, the Jabra Pro 920 should be able to be connected to the Yealink T48G. The pairing of the "Swisscom software" (whichever it is) with the Jabra has nothing to do with each other ... or then I understand the question completely wrong. There are 3 components involved here (phone, headset and an unknown Swisscom software).