Maximum Number Of Stations Per Ring With Various Cabling Types

The Intel® Token Ring Network Adapters have been tested as having one of the industry's lowest jitter values, both concerning "correlated" and "un-correlated" jitter, which means that by using the Intel adapters, users can build networks which meet or exceed all required Industry Standards concerning maximum number of workstations per ring or maximum length of the lobe cables.

The Intel® Token Ring Network Adapters are guaranteed to meet or exceed all cabling specifications outlined in the "IBM Token Ring Network Introduction and Planning Guide" and in the "IBM Local Area Network Technical Reference Manual". As an example, for 100 meter (328 Feet) lobe length, a total of 136 adapters (connected via 17 MAU's) are guaranteed to be supported at 16 Mbps operation. Using shorter lobe lengths will allow additional Adapters.

The IEEE 802.5 Standard calls for a maximum of 250 adapters on one single ring. At this time, 16 Mbps rings with more than 260 workstations using Intel's Token Ring network adapters and connected via "type-1 (shielded twisted pair) cabling" have been tested without showing even a single error. TokenExpress supports 150ohms on STP cable and 100ohms on UTP cable.

For 16 Mbps operation, Intel guarantees a MAXIMUM ADAPTER LOBE LENGTH, measured as total cable length between the MAU and the adapter's connector, of:

173 Meters/568 Feet

In addition, although no industry-wide specification for operation via "type-3 (unshielded twisted pair)" cabling exists at this time, recent measurements have shown the Intel Token Ring network adapters running via the Intel "16/4 Mbps on board Type-3 Media Filter" will meet or exceed one of the "de facto" Industry Standards of:

At least 72 Token Ring Workstations with up to 65 meters (213 feet) lobe lengths on one ring via IBM specified "type-3 or unshielded twisted pair" (Belden 1154A T3M E 24 AWG) cabling At least 104 Token Ring Workstations with up to 100 meters (328 feet) lobe length on one ring via AT&T Systimax 2061 Cabling At least 72 Token Ring Workstations with at least 70 meters (230 feet) lobe lengths on one ring via AT&T Systimax PDS DIW 4/24 cabling

To accommodate future network growth using multiple MAU's at 16 MBps operation, the Network should be planned using the following tables for typical ADAPTER LOBE LENGTHS for single-wiring-closet "type-1" or "type-2" (STP) cabled networks:

All Lobe Cable Length in Meters

# of MAU's

         <---------------- Number of Racks ---------------->
            1   2    3    4    5    6    7    8    9    10
       -----------------------------------------------------
      1 | 173                                             |
      2 | 167  160                                        |
      3 | 163  156  151                                   |
      4 | 159  152  147  142                              |
      5 | 156  148  143  138  133                         |
      6 | 152  144  139  134  129  124                    |
      7 | 148  140  135  130  125  120  115               |
      8 | 145  136  131  126  121  116  111  106          |
      9 | 141  132  127  122  117  112  107  102   97     |
     10 | 137  128  123  118  113  108  103   98   93   88|
     11 | 134  124  119  114  109  104   99   94   89   84|
     12 | 130  121  116  111  106  101   96   91   86   81|
   * 13 | 116  117  112  107  102   97   92   87   82   77|
   * 14 | 112  113  108  103   98   93   88   83   78   73|
   * 15 | 109  109  104   99   94   89   84   79   74   69|
   * 16 | 105  105  100   95   90   85   80   75   70   65|
   * 17 | 101  101   96   91   86   81   76   71   66   61|
   * 18 |  98   97   92   87   82   77   72   67   62   57|
   * 19 |  94   93   88   83   78   73   68   63   58   53|
   * 20 |  90   85   80   75   70   65   60   55   50   45|
   * 21 |  87   77   72   67   62   57   52   47   42   37|
   * 22 |  83   69   64   59   54   49   44   39   34   29|
   * 23 |  79   61   56   51   46   41   36   31   26   21|
   * 24 |  75   53   48   43   38   33   28   23   18   13|
   * 25 |  67   40   35   30   25   20   15   10    5     |
   * 26 |  63   32   27   22   17   12    7               |
   * 27 |  59   23   18   13    8    3                    |
   * 28 |  56   15   10    5                              |
   * 29 |  52    7                                        |
   * 30 |  48                                             |
   * 31 |  45                                             |
   * 32 |  41                                             |
   * 33 |  37                                             |
   --------------------------------------------------------

Intel® Network Planning Guide Using "TYPE-1" STP Cabling (In Feet) To accommodate future network growth using multiple MAU's at 16 MBps operation, the Network should be planned using the following tables for typical ADAPTER LOBE LENGTHS for single-wiring-closet "type-1" or "type-2" STP cabled networks:

All Lobe Cable lengths in Feet

# MAU's

       <---------------- Number of Racks ---------------->
          1    2    3    4    5    6    7    8    9    10
     ----------------------------------------------------
     1 | 569                                             |
     2 | 556  524                                        |
     3 | 544  511  494                                   |
     4 | 531  498  482  465                              |
     5 | 518  485  469  452  436                         |
     6 | 505  472  456  439  423  407                    |
     7 | 492  459  443  427  410  394  377               |
     8 | 479  447  430  414  397  381  365  348          |
     9 | 467  434  417  401  385  368  352  335  319     |
    10 | 454  421  405  388  372  355  339  323  306  290|
    11 | 441  408  392  375  359  343  326  310  293  277|
    12 | 428  395  379  363  346  330  313  297  281  264|
    13 |*380  383  366  350  333  317  300  284  268  251|
    14 |*367  370  353  337  320  304  288  271  255  238|
    15 |*358  357  340  324  308  291  275  258  242  226|
    16 |*344  344  328  311  295  278  262  246  229  213|
    17 |*331  331  315  298  282  266  249  233  216  200|
    18 |*321  318  302  286  269  253  236  220  204  187|
    19 |*308  306  289  273  256  240  224  207  191  174|
    20 |*295  280  264  247  231  214  198  181  165  149|
    21 |*285  251  235  218  202  185  169  153  136  120|
    22 |*272  225  209  193  176  160  143  127  111   94|
    23 |*259  200  183  167  150  134  118  101   85   68|
    24 |*246  174  158  141  125  108   92   76   59   43|
    25 |*220       132  116   99   83   66   50   34   17|
    26 |*207       106   90   74   57   41   24          |
    27 |*193        74   58   41   25    9               |
    28 |*183        49   32   16                         |
    29 |*171        23                                   |
    30 |*157                                             |
    31 |*148                                             |
    32 |*135                                             |
    33 |*121                                             |
      ---------------------------------------------------

Intel® Network Planning Guide Using "TYPE-3" UTP Cabling (In Meters)

To accommodate future network growth using multiple MAU's at 16 MBps operation, the Network should be planned using the following tables for typical ADAPTER LOBE LENGTHS for single-wiring-closet "type-3" cabled networks:

All Lobe Cable lengths in meters

Number Of Adapters	Number Of MAU's	Belden 1154A 24AWG	Systimax PDS 206	Systimax PDS DIW 14/24
1-8	1	82	125	87
9-16	2	79	122	84
17-24	3	77	120	82
25-32	4	75	118	80
33-40	5	73	116	78
41-48	6	71	114	76
49-56	7	69	112	74
57-64	8	67	110	72
65-72	9	65	108	70
73-80	10		106
81-88	11		104
89-96	12		102
97-104	13		100

All lengths are in Meters. For length in Feet, multiply above lengths with a factor of 3.28.

Note: Distance between MAU's = 7 Feet = 2.13 Meters. Maximum 12 MAU's per Rack.

Note: Due to type-3 cabling being un-shielded, networks based on type-3 cabling are sensitive to the electrical environment; how the cables are physically run and distances from electrically "noisy" components (power transformers, motors, etc.). In addition, the electrical characteristics of the cables may vary. For instance, for older versions of the "Belden 1154A T3M 24 AWG" cable, laboratory measurements of up to 130 Meters have been measured for maximum error-free adapter drive distance.

NOTE: Level 3 cable has 2 twists per foot. Higher levels have more twists per foot.

Intel®  Network Planning Guide - Planning Formulas

Cable Budget =

(longest lobe length) plus (total length of all cables between all MAU's).

(2 * longest lobe length) plus (total length of all cables between all MAU's).

(total length of all cables between all MAU's) minus (length of shortest cable between MAU's).

Worst Case Maximum Adapter Signal Drive Distance =

2 * ((longest lobe length) plus (Adjusted Ring Length)) = 2 * ((longest lobe length) plus (total length of all cables between all MAU's) - (length of shortest cable connecting two MAU's)).

This applies to:

TokenExpress™ 16/p Adapter TokenExpress™ EISA 16/4 Adapter TokenExpress™ EISA 32 Adapter TokenExpress™ MCA Adapter TokenExpress™ PRO LAN Adapter