M1 Network Configuration


Network Group 0-7	Network Shelf 0-1	Loops 0-255	INI HEX Code	Super Loops 0-252	PER SIGS 0-15	3PE Software LD	IGS 1	Junctor Jacks J1-J22		IGS 0

Group 0	Shelf 0	0-15	9x	0, 4, 8, 12	0 (4x)	0G0 (EX)	2 (5x)	J6	J1	0 (5x)
Group 0	Shelf 1	16-31	Ax	16, 20, 24, 28	1	1G0 (Fx)	3	J17	J22	1

Group 1	Shelf 0	32-47	Bx	32, 36, 40, 44	2	0G1	6	J7	J2	4
Group 1	Shelf 1	48-63	Cx	48, 52, 56, 60	3	1G1	7	J16	J21	5

Group 2	Shelf 0	64-79	Dx	64, 68, 72, 76	4	0G2	10	J8	J3	8
Group 2	Shelf 1	80-95	19x	80, 84, 88, 92	5	1G2	11	J15	J20	9

Group 3	Shelf 0	96-111	1Ax	96, 100, 104, 108	6	0G3	14	J9	J4	12
Group 3	Shelf 1	112-127	1Bx	112, 116, 120, 124	7	1G3	15	J14	J19	13

Group 4	Shelf 0	128-143	1Cx	128, 132, 136, 140	8	0G4	18 (6x)	J10	J5	16 (6x)
Group 4	Shelf 1	144-159	1Dx	144, 148, 152, 156	9	1G4	19 (6x)	J13	J18	17 (6x)

Group 5	Shelf 0	160-175	13x	160, 164, 168, 172	10	0G5	-	-	-	-
Group 5	Shelf 1	176-191	14x	176, 180, 184, 188	11	1G5	-	-	-	-

Group 6	Shelf 0	192-207	15x	192, 196, 200, 204	12	0G6	-	-	-	-
Group 6	Shelf 1	208-223	16x	208, 212, 216, 220	13	1G6	-	-	-	-

Group 7	Shelf 0	224-239	17x	224, 228, 232, 236	14	0G7	-	-	-	-
Group 7	Shelf 1	240-255	18x	240, 244, 248, 252	15	1G7	-	-	-	-

M1 System Sizes:

Option 21E - 6 ENETS + 1 Superloop or 7 Loops
Option 51/51C - 1/2 Network Group (16 Loops 0-15)
Option 61/61C - 1 Full Network Group (32 Loops 0-31)
Option 71/81/81C with IGS - Up to 5 Network Groups 0-4 (160 Loops 0-159)
Option 81 & 81C with FNF - Up to 8 Network Groups 0-7 (256 Loops 0-255)

Some background info - from the days before IP!

The system uses 'timeslots' to connect each party on an active call. These timeslots are present on Network Equipment components called Loops. Each Loop has 30 timeslots, and Super-loops have 120 timeslots (4 loops). Loop and Super-loop cards sit in the Network Equipment shelves, there are 16 Loops per Network shelf. 32 loops are called a Group (eg, 2 Network shelves). The Option 81C is called a multi-group system because you can equip up to five Network groups. This was later expanded to 8 Network groups with a dual ring fiber optic network replacing the intergroup cards and intergroup module, providing a maximum of 7680 timeslots!

What is a Timeslot?: A timeslot is one (64Kbps) voice channel
What is a Loop?: A loop is a collection of 30 timeslots
What is a Slot?: A slot is a physical single card location within a network or IPE shelf; In a Network Shelf, one slot provides two loops, ie: 60 timeslots
What is a Super Loop?: 1 Super Loop = 4 Loops; Thus one Super Loop contains 120 timeslots, and takes up 2 slots in a Network shelf
What is a Network Shelf?: A collection of 8 physical slots, or 16 network Loops (4 Super Loops)
What is a Network Group?: A pair of Network Shelves (8 Super Loops)
Summary:: 1 Loop = 30 timeslots; 1 Slot = 2 Loops = 60 timeslots; 1 Super Loop = 2 slots = 4 Loops = 120 timeslots; 1 Network Shelf = 4 Super Loops = 8 Slots = 16 Loops = 480 timeslots; 1 Network Group = 2 Network Shelves = 8 Super Loops = 16 Slots = 960 timeslots; 8 Network Groups = 64 Super Loops = 256 Loops = 7680 timeslots (256 loops x 30 timeslots)