POWER OF ATTORNEY


KNOW ALL MEN BY THESE PRESENTS, that the undersigned constitutes and appoints
James E. Matthews, Cathy Bartels, and Gayle Ellis, and each of them, his true
and lawful attorneys-in-fact and agents, with full power of substitution, for
him and in his name, place and stead, in any and all capacities, to:

1. Execute for and on behalf of the undersigned, in the undersigned's capacity
as an officer and/or director of
ADTRAN, Inc. (the "Company"), Forms 3, 4 and 5 in accordance with Section 16(a)
of the Securities Exchange Act of 1934, as amended, and the rules thereunder;
2. do and perform any and all acts for and on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Form 3, 4 or 5
and timely file such form with the United States Securities and Exchange
Commission and any stock exchange or similar authority; and
3. take any other action of any type whatsoever in connection with the foregoing
which, in the opinion of such attorney-in-fact, may be of benefit to, in the
best interest of, or legally required by, the undersigned, it being understood
that the documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve in such
attorney-in-fact's discretion.
The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-
fact, or such attorney-in-fact's substitute or substitutes, shall lawfully do or
cause to be done by virtue of this power of attorney and the rights and powers
herein granted.

The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in
such capacity at the request of
the undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to
comply with Section 16 of the Securities Exchange Act of 1934. This Power of
Attorney shall remain in full force and effect until the undersigned is no
longer required to file Forms 3, 4 and 5 with respect to the undersigned's
holdings of and transactions in securities issued by the Company, unless earlier
revoked by the undersigned in
assigned writing delivered to the foregoing attorneys-in-fact.
IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 5th day of May, 2010.





Signature
       William L. Marks	May 5, 2010
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