CALCULATING RING LENGTH
Page C-7
STP CABLE LENGTH WORKSHEET
1. Maximum Drive Limit
2. Internal Trunk Length
3. Maximum Type 1 Lobe Length
4. Actual Longest Lobe
Single Wiring Closet
(1263 feet for 4 Mbit/s or 569 feet for 16 Mbit/s)
(1) – (2) = (3)
(Value from Table below)
4 Mbit/sec
16 Mbit/sec
569 ft.
5. If you get a negative result, adjust
cable lengths or add active
components to the ring.
1.
2.
–
ft.
3.
ft.
5.
4.
ft.
–
1263 ft.
1.
2.
–
ft.
3.
ft.
5.
4.
ft.
–
Number of
Number of Racks (Single Closet)
Concentrators 1
2
3
4
5
6
7
8
9
10
1
12
2
24
90
Values are Type 1
3
36
102
135
Equivalent in feet
4
48
114
147
180
5
60
126
159
192
225
6
72
138
171
204
237
270
7
84
150
183
216
249
282
315
8
96
162
195
228
261
294
327
360
9
108
174
207
240
273
306
339
372
405
10
120
186
219
252
285
318
351
384
417
450
11
132
198
231
264
297
330
363
396
429
462
12
144
210
243
276
309
342
375
408
441
474
13
222
255
288
321
354
387
420
453
486
14
234
267
300
333
366
399
432
465
498
15
246
279
312
345
378
411
444
477
510
16
258
291
324
357
390
423
456
489
522
17
270
303
336
369
402
435
468
501
534
18
282
315
348
381
414
447
480
513
546
19
294
327
360
393
426
459
492
525
558
20
306
339
372
405
438
471
504
537
570
21
318
351
384
417
450
483
516
549
582
22
330
363
396
429
462
495
528
561
594
23
342
375
408
441
474
507
540
573
606
24
354
387
420
453
486
519
552
585
618
25
399
432
465
498
531
564
597
630
26
411
444
477
510
543
576
609
642
27
423
456
489
522
555
588
621
654
28
435
468
501
534
567
600
633
666
29
447
480
513
546
579
612
645
678
30
459
492
525
558
591
624
657
690
31
471
504
537
570
603
636
669
702
32
483
516
549
582
615
648
681
714
33
495
528
561
594
627
660
693
726