|  | 
      
      
        
          | Option # | Top Level Part #
 | Manufacturing Part #
 | Description | Substitute Part #
 |  
          | X1155A | 605-1611 | 370-2728
              [F] | High Speed Serial Interface (HSI/P) 2.0 | n/a |  
          | X1157A | 605-1623 | 501-3028
              [F] | SunATM-155/MFiber 4.0 | n/a |  
          | X1158A | 605-1624 | 501-3027
              [F] | SunATM-155/UTP 4.0 | n/a |  
          | X1159A | 605-1625 | 501-3029 [F] | SunATM-622/MFiber 4.0 | n/a |  
          | X2156A | 605-1644 | 375-0100
              [F] | Serial Asynchronous Interface (SAI/P) 3.0 | n/a |  
           
            | Table Legend |   
            | [F] = Field Replaceable 
              Unit (FRU) [S] = Supported, but can no longer be ordered 
              with this system
 [N] = No longer supported for this system
 |  |