Optical Fiber Interoperability: Using Fiber Standards and Specifications to Ensure Reliable Network PerformanceStandards for singlemode optical fiber are published by several different organizations, including the ITU, the IEC, the TIA and Telcordia. Their documents contain an alphabet soup of abbreviations. For example, the commonly used ITU G.657.A1 singlemode fiber can also be referred to as OS2, IEC 60793-2-50 B6_A1 and TIA-492CAAB. On top of that, each Tier 1 fiber manufacturer markets several different singlemode products, which can lead to confusion about which fiber grades to specify and whether or not different fibers can be mixed in a network,