What's the name of the socket where the crystal head plugs into the phone?

The socket of the crystal plug phone is called RJ 1 1 interface.

The RJ 1 1 interface is very similar to the RJ45 interface, but only has 2 or 4 pins (RJ45 has 8 pins). In computer systems, RJ 1 1 is mainly used to connect modems.

In the General Integrated Wiring Standard,' RJ11'is not mentioned separately, and all connecting devices must be 8 pins. Therefore, the collaboration and compatibility between RJ 1 1 and RJ45 are not written.

The name RJ stands for registered Jack, USOC from Bell Systems.

(universal service subscription code) code. USOC is a series of registered jacks and their connection modes, which were developed by Bell Systems for connecting user equipment to public networks. FCC regulations control the application of this purpose. The FCC (Federal Communications Commission) issued a document on behalf of the US government, stipulating RJ 1 1.

RJ 1 1 is the general name of the connector developed by western electric company ... its shape is defined as a 6-pin connection device. Formerly known as WExW, where x stands for' activity', contact or sewing needle. For example,

WE6W has all 6 contacts numbered from 1 to 6. We4W interface only uses the outermost two contacts of 4 pins (1 and 6), and WE2W only uses the middle two pins. For RJ 1 1, the information sources are contradictory. It can be a 2-core or 4-core 6-pin connector. What is even more confusing is that RJ 1 1 is not only used to represent a 6-pin connector, but also refers to a 4-pin version.