August 16, 2019
Different standards, different sizes (RJ11 has 6P6C6P4C4P4C4P2C, where C stands for the number of gold needles in the crystal head; RJ45 has 8P8C).
Due to the different sizes of the two (RJ11 is 4 or 6 pins, RJ45 is 8-pin connector), it is obvious that the RJ45 plug cannot be inserted into the RJ11 jack. The reverse is physically feasible (the RJ11 plug is smaller than the RJ45 jack), which makes people mistakenly think that the two should work together. This is actually not the case. It is highly recommended not to use the RJ11 plug for the RJ45 jack.