Jacks, Plugs, and Blocks

The Universal Service Ordering Codes (USOC) Registered Jack Configurations (RJ):

USOC RJ-61	USOC RJ-25	USOC RJ-14	USOC RJ-11
USOC RJ-31X	USOC RJ-48X	USOC RJ-48S	USOC RJ-45S

Other Configurations:

Unshielded Twisted-Pair Blocks

A 110-Type Cross-Connect Block looks like this:

A 66-Type Cross-Connect Block looks like this:

110 and 66 blocks pin-out as follows:

Or more clearly:

Wire	Tip/Ring and color	Pair Number	50-pin Cable Connector Positions	66/110 Block Positions
	T=white/blue R=blue/white	Pair 1	26 1	1 2
	T=white/orange R=orange/white	Pair 2	27 2	3 4
	T=white/green R=green/white	Pair 3	28 3	5 6
	T=white/brown R=brown/white	Pair 4	29 4	7 8
	T=white/slate R=slate/white	Pair 5	30 5	9 10
	T=red/blue R=blue/red	Pair 6	31 6	11 12
	T=red/orange R=orange/red	Pair 7	32 7	13 14
	T=red/green R=green/red	Pair 8	33 8	15 16
	T=red/brown R=brown/red	Pair 9	34 9	17 18
	T=red/slate R=slate/red	Pair 10	35 10	19 20
	T=black/blue R=blue/black	Pair 11	36 11	21 22
	T=black/orange R=orange/black	Pair 12	37 12	23 24
	T=black/green R=green/black	Pair 13	38 13	25 26
	T=black/brown R=brown/black	Pair 14	39 14	27 28
	T=black/slate R=slate/black	Pair 15	40 15	29 30
	T=yellow/blue R=blue/yellow	Pair 16	41 16	31 32
	T=yellow/orange R=orange/yellow	Pair 17	42 17	33 34
	T=yellow/green R=green/yellow	Pair 18	43 18	35 36
	T=yellow/brown R=brown/yellow	Pair 19	44 19	37 38
	T=yellow/slate R=slate/yellow	Pair 20	45 20	39 40
	T=violet/blue R=blue/violet	Pair 21	46 21	41 42
	T=violet/orange R=orange/violet	Pair 22	47 22	43 44
	T=violet/green R=green/violet	Pair 23	48 23	45 46
	T=violet/brown R=brown/violet	Pair 24	49 24	47 48
	T=violet/slate R=slate/violet	Pair 25	50 25	49 50

Optical Fiber

Plugs and Jacks

Patch Panels for Cross-Connects

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