exhibit 2. 1 execution copy asset sale and purchase agreement dated 11 december 2011 regarding the sale and purchase of the nsn dslam, gpon and aci products and the related services businesses bird & bird / metis aspa execution copy project london 11. 12. 2011 between 1. nokia siemens networks b. v., werner von siemensstraat 7, 2712pn zoetermeer, the netherlands, a limited liability company ( besloten vennootschap met beperkte aansprakelijkheid – b. v. ) under the laws of the netherlands, registered in the trade register under the number 34259706, - “ parent seller ” - 2. nokia siemens networks gmbh & co. kg, st. - martin - straße 76, 81541 munich, germany, a german private limited partnership ( kommanditgesellschaft ), registered with the commercial register of munich under the number hra 88537, - “ seller subsidiary 1 ” - - parent seller and seller subsidiary 1 collectively the “ sellers ” and each a “ seller ” - 3. adtran gmbh, c / o metis rechtsanwalte llp, untermainkai 30, 60329 frankfurt / main, a german limited liability company ( gesellschaft mit beschrankter haftung ), registered with the commercial register of charlottenburg under the number hrb 135656 b, - “ purchaser ” - 4. adtran, inc., a corporation under the laws of the state of delaware, usa, with its principal office at 901 explorer boulevard, huntsville, alabama 35806, usa, - “ purchaser ’ s parent ” - - parent seller, seller subsidiary 1 and purchaser are hereinafter also collectively referred to as the “ parties ” and each as a “ party ” - 2 execution copy table of content september 30, page table of content 3 index of defined terms 4 preamble 6 1. selected defined terms and abbreviations 7 2. scope of transaction and purchaser transfer right 8 3. the sold business 9 4. the sold business pertaining to seller subsidiaries 14 5. updates 15 6. sale, assignment and transfer, assumption of the sold business 16 7. third party consents, purchaser ’ s indemnification covenants, release of payments and subcontracting 20 8. new agreements between sellers and purchaser 23 9