{E is a series of Recommendations (standards) from the Standardization Sector the International Telecommunication Union ( ITU-T), the description of the E series is: "Overall network operation, telephone service, service operation and human factors".
{E is a series of Recommendations (standards) from the Standardization Sector the International Telecommunication Union ( ITU-T), the description of the E series is: "Overall network operation, telephone service, service operation and human factors".