What Does XJACK Mean?
XJACK is a laptop computer connector that connects a telephone jack to a computer’s internal slim PCMCIA card modem using a standard RJ11 or RJ45 plug.
Today, XJACK is a type of extendable connector or antenna that picks up a local area network (LAN) or wireless signal as part of a type II PC card. When the XJACK is not being used, it retracts into the PC card. Larger type III cards use a regular RJ-type socket but require more space.