Littelfuse, Inc holds the Chair position for the ITU-T working group that oversees the ITU-T K20/21/44/45 recommendations. The ITU K44 was updated in 2012 with its publication date following in 2013. The K20/21/45 should be updated during 2015, adding clarification to Ethernet and USB port testing. The K44 is the base document, with K20 specifying telecommunication center resistibility levels, K.21 specifying customer premises resistibility levels, and K.45 specifying remote terminal/access equipment resistibility levels. The ITU recommendations use two basic surge simulation waveforms: 10/700µS voltage waveshape, 5/310µS current waveshape OR the 1.2/50µS voltage waveshape with its associated 8/20µS  short circuit waveshape. The ITU recommendations defer to the IEC series of documents for ESD testing definitions and levels. These recommendations will call out for an air- ESD discharge event and a contact ESD discharge event repeated five times. These recommendations use two terms: Basic and Enhanced. Enhanced level testing was initially intended for applications located in Nordic regions where perma-frost causes grounding issues, but some customers are now requiring Enhanced compliance due to the severity of lightning exposure for some outside locations in high lightning activity regions of the world. Otherwise, the Basic levels are used for compliance testing.