ADTRAN, Inc. is a provider of telecommunications network equipment and related products. Headquartered in Huntsville, Alabama.The company is ISO 9001 and TL9000 certified. ADTRAN was the Nasdaq-100 from 1996 to 1998. #85 was on 100 "hot growth companies" in the 100 list in 2006. ADTRAN was founded by Mark C. Smith and Lonnie McMille, and began operations in 1986. AT&T, which is liquidating Bell's regional operators, with restrictions effectively preventing its equipment manufacturing, has provided an opportunity for companies such as ADTRAN to supply network equipment, both for the Seven RBOCs and new and independent phone companies in the United States. ADTRAN adapting telephony technology for use in enterprise-wide networks. ADTRAN has become a supplier of access to local loop and deployment products for fiber, DS3, T1/E1, T1/E1 wireless, digital common line (HDSL, HDSL2, HDSL, SDSL, SHDSL), frame relay, asynchronous transport mode (ATM), integrated digital network services (ISDN), and digital digital data service services (DDS). ADTRAN provides multi-service access platforms and integrated access devices (IADs) for converged audio and data networks.