<PAGE>   1

                                                                    EXHIBIT 4.14



                          SECOND SUPPLEMENTAL INDENTURE


               Second Supplemental Indenture, dated as of December 22, 1997, by
and among IXC Communications, Inc., a Delaware corporation (the "Company"), each
of the Guarantors listed on the signature page hereto and IBJ Schroder Bank &
Trust Company, as trustee (the "Trustee"), under the Indenture dated as of
October 5, 1995, as amended by Amendment No. 1 to Indenture and Subsidiary
Guaranty dated as of June 4, 1996 and supplemented by the First Supplemental
Indenture dated as of October 23, 1997 among the Company, the Guarantors listed
on the signature pages thereto (the "Guarantors"), and the Trustee (as amended
and supplemented, the "Indenture") pursuant to which the Company's 12 1/2%
Senior Notes due 2005 (the "Senior Notes") were issued. Capitalized terms used
herein, but otherwise not defined herein, shall have the meanings given to such
terms in the Indenture.

               WHEREAS, the Board of Directors of the Company has determined
that it is in the best interests of the Company to authorize and approve an
amendment to the Indenture, in accordance with subparagraph (d) of Section 9.01
of the Indenture, in order to add IXC Internet Services, Inc. ("IXC Internet" or
the "New Guarantor ") as a Guarantor pursuant to the requirements of the
Indenture; and

               WHEREAS, Section 9.01 of the Indenture provides, among other
things, that the Company and the Trustee may amend or supplement the Indenture
as provided herein without the consent of any Holder to make any change that
would provide additional rights or benefits to the Holders of the Senior Notes
or that does not adversely affect the legal rights thereunder of any Holder of
the Senior Note; and

               WHEREAS, all acts and proceedings required by law, the Indenture
and the charter documents of the Company necessary to constitute this Second
Supplemental Indenture as a valid and binding agreement for the uses and
purposes herein set forth, in accordance with its terms, have been done and
taken; and the execution and delivery of this Second Supplemental Indenture by
the Company and each of the Guarantors have been in all respects duly
authorized; and

               WHEREAS, the Company has furnished the Trustee with (i) an
Officers' Certificate and an Opinion of Counsel stating that the conditions
precedent to the execution by the Trustee of this Second Supplemental Indenture
have been satisfied, (ii) resolutions of the Company, each of the Guarantors and
IXC Internet, authorizing the execution of the Second Supplemental Indenture,
and (iii) a request of the Company.

               NOW, THEREFORE, each party hereto, for the equal and
proportionate benefit of the other parties hereto and the Holders, are executing
and delivering this Second Supplemental Indenture.



<PAGE>   2

        Section 1. Guarantee by IXC Internet.

               For value received, IXC Internet agrees to become a party to the
Indenture as a Guarantor under and pursuant to the provisions of the Indenture
and hereby agrees to be bound by the terms and conditions set forth in the New
Subsidiary Guarantee set forth in Exhibit A attached hereto.

        Section 2. Miscellaneous.

                a. Effect of Second Supplemental Indenture. Upon the execution
and delivery of this Second Supplemental Indenture by the Company, the
Guarantors and the Trustee, the Indenture shall be supplemented in accordance
herewith, and this Second Supplemental Indenture shall form a part of the
Indenture for all purposes, and every Holder of Senior Notes heretofore or
hereafter authenticated and delivered under the Indenture shall be bound hereby.

                b. Indenture Remains in Full Force and Effect. Except as
supplemented hereby, all provisions in the Indenture shall remain in full force
and effect.

                c. Ratification of Indenture. As amended by this Second
Supplemental Indenture, the Indenture is in all respects ratified and confirmed
and, as so supplemented by this Second Supplemental Indenture, shall be read,
taken and construed as one and the same instrument.

                d. Confirmation and Preservation of Indenture. The Indenture as
supplemented by this Second Supplemental Indenture is in all respects confirmed
and preserved.

                e. Conflict with Trust Indenture Act. If any provision of this
Second Supplemental Indenture limits, qualifies or conflicts with any provision
of the TIA that is required under the TIA to be part of and govern any provision
of this Second Supplemental Indenture, the provision of the TIA shall control.
If any provision of this Second Supplemental Indenture modifies or excludes any
provision of the TIA that may be so modified or excluded, the provision of the
TIA shall be deemed to apply to the Indenture as so modified or to be excluded
by this Second Supplemental Indenture, as the case may be.

                f. Severability. In case any provision in this Second
Supplemental Indenture shall be invalid, illegal or unenforceable, the validity,
legality and enforceability of the remaining provisions shall not in any way be
affected or impaired thereby.

                g. Headings. The Section headings of this Second Supplemental
Indenture have been inserted for convenience of reference only, are not to be
considered a part of this Second Supplemental Indenture and shall in no way
modify or restrict any of the terms or provisions hereof.

                h. Benefits of Second Supplemental Indenture, etc. Nothing in
this Second Supplemental Indenture or the Senior Notes, express or implied,
shall give to any Person, other than




                                      - 2 -

<PAGE>   3

the parties hereto and thereto and their successors hereunder and thereunder and
the Holders of the Senior Notes, any benefit of any legal or equitable right,
remedy or claim under the Indenture, this Second Supplemental Indenture or the
Senior Notes.

                i. Successors. All agreements of the Company and in this Second
Supplemental Indenture shall bind its successors. All agreements of the Trustee
in this Second Supplemental Indenture shall bind its successors.

                j. The Trustee. In entering into this Second Supplemental
Indenture, the Trustee shall be entitled to the benefit of every provision of
the Indenture relating to the conduct or affecting the liability or affording
protection to the Trustee. The Trustee shall not be responsible in any manner
whatsoever for the recitals of fact herein, all of which are made by the Company
and the Guarantors.

                k. Governing Law. The internal law of the State of New York
shall govern and be used to construe this Second Supplemental Indenture without
regard to principals of conflict of laws thereof.

                l. Events of Default. To the extent provisions of the Indenture
have been deleted by this Second Supplemental Indenture, the Company is hereby
relieved of its obligations under such provisions and such provisions shall not
hereafter give rise to a Default or an Event of Default. To the extent
provisions of the Indenture have been amended by this Second Supplemental
Indenture, a Default or an Event of Default may arise hereafter under such
provisions only as amended.

                m. The Effective Date. This Second Supplemental Indenture shall
become a legally effective and binding instrument upon the execution and
delivery hereof by all parties hereto.

                n. Counterparts. This Second Supplemental Indenture may be
executed in any number of counterparts and by the parties hereto in separate
counterparts, each of which so executed shall be deemed to be an original, but
all of such counterparts shall together constitute but one and the same
agreement.












                                      - 3 -

<PAGE>   4



        IN WITNESS WHEREOF, the parties hereto have caused this Second
Supplemental Indenture to be executed by their respective officers, thereunto
duly authorized and attested, all as of the day and year first above written.


                                      "Company"

Attest:                               IXC COMMUNICATIONS, INC.,


By:     /s/ Jeffrey C. Smith          By:     /s/ James F. Guthrie
      -------------------------------       ------------------------------------
Name:   Jeffrey C. Smith              Name:   James F. Guthrie
Title:  Senior Vice President,        Title:  Executive Vice President and Chief
        General Counsel and Secretary         Financial Officer

                                      "Guarantors"
                                      ATLANTIC STATES MICROWAVE
                                         TRANSMISSION COMPANY
                                      CENTRAL STATES MICROWAVE
                                         TRANSMISSION COMPANY
                                      TELCOM ENGINEERING, INC.
                                      TOWER COMMUNICATION SYSTEMS CORP.
                                      WEST TEXAS MICROWAVE COMPANY
                                      WESTERN STATES MICROWAVE
                                         TRANSMISSION COMPANY
                                      RIO GRANDE TRANSMISSION, INC.
                                      IXC CARRIER, INC.
                                      IXC LONG DISTANCE, INC.
                                      LINK NET INTERNATIONAL, INC.
                                      IXC INTERNATIONAL, INC.
Attest:                               IXC INTERNET SERVICES, INC.



By:     /s/ Jeffrey C. Smith          By:     /s/ James F. Guthrie
      -------------------------------       ------------------------------------
Name:   Jeffrey C. Smith              Name:   James F. Guthrie
Title:  Senior Vice President,        Title:  Executive Vice President and Chief
        General Counsel and Secretary         Financial Officer






                                      - 4 -

<PAGE>   5

                                      "Trustee"


Attest:                               IBJ SCHRODER BANK & TRUST
                                      COMPANY


By:     /s/ Barbara McCluskey         By:     /s/ Terence Rawlins
      -------------------------------       ------------------------------------
Name:   Barbara McCluskey             Name:   Terence Rawlins
Title:  Assistant Secretary           Title:  Assistance Vice President



























                                      - 5 -

<PAGE>   6


                                    EXHIBIT A
                            NEW SUBSIDIARY GUARANTEE


               The New Guarantor (which term includes any successors or assigns
under the Indenture), agrees to irrevocably and unconditionally guaranteed on an
unsecured basis (i) the due and punctual payment of the principal of, and
premium and Liquidated Damages, if any, and interest on the Senior Notes,
whether at stated maturity, by acceleration or otherwise, the due and punctual
payment of interest on the overdue principal of, and premium if any, and (to the
extent permitted by law) interest, and Liquidated Damages on any interest, if
any, on the Senior Notes, and the due and punctual performance of all other
obligations of the Company, to the Holders or the Trustee all in accordance with
the terms set forth in the Indenture, (ii) in case of any extension of time of
payment or renewal of any Senior Notes or any such other obligations, that the
same will be promptly paid in full when due or performed in accordance with the
terms of the extension or renewal, whether at stated maturity, by acceleration
or otherwise, and (iii) the payment of any and all costs and expenses (including
reasonable attorneys' fees) incurred by the Trustee or any Holder in enforcing
any rights under this New Subsidiary Guarantee.

               The obligations of the New Guarantor to the Holders and to the
Trustee pursuant to this New Subsidiary Guarantee and the Indenture are
expressly set forth in Article 11 of the Indenture and reference is hereby made
to such Indenture for the precise terms of this Guarantee.

               No stockholder, officer, director, or incorporator, as such,
past, present or future of the New Guarantor shall have any liability under this
New Subsidiary Guarantee by reason of his or its status as such stockholder,
officer, director or incorporator.

               This is a continuing Guarantee and shall remain in full force and
effect and shall be binding upon the each New Guarantor and its successors and
assigns until full and final payment of all of the Company's obligations under
the Senior Notes and Indenture and shall inure to the benefit of the successors
and assigns of the Trustee and the Holders, and, in the event of any transfer or
assignment of rights by any Holder or the Trustee, the rights and privileges
herein conferred upon that party shall automatically extend to and be vested in
such transferee or assignee, all subject to the terms and conditions hereof.
This is a Guarantee of payment and not of collectibility.

               Any term or provision of this Guarantee to the contrary
notwithstanding, the aggregate amount of the Obligations guaranteed hereunder
shall be reduced to the extent necessary to prevent this Guarantee from
violating or becoming voidable under applicable law relating to fraudulent
conveyance or fraudulent transfer or similar laws affecting the rights of
creditors generally.

               The Obligations of the New Guarantor under the New Subsidiary
Guarantee pursuant to Article 11 of the Indenture shall be senior to the
Indebtedness of the New Guarantor on the same basis as the Senior Notes are
senior to the Indebtedness of the Company. For purposes of the foregoing
sentence, (a) the New Guarantor may make, and the Trustee and the Holders of the
Notes have the right to receive and/or retain, payments by the New Guarantor
only at such times as they may receive and/or retain payments in respect of the
Senior Notes pursuant to the Indenture, including Article 11 thereof, and (b)
the rights and obligations of the relevant parties relative to the New
Subsidiary Guarantee and the New Guarantor's Indebtedness shall be the same as
their respective rights and obligations relative to the Senior Notes of the
Company pursuant to Article 11 of the Indenture.




                                      - 6 -

<PAGE>   7

               THE TERMS OF ARTICLE 11 OF THE INDENTURE ARE INCORPORATED
HEREIN BY REFERENCE.

               Capitalized terms used herein have the same meanings given in the
Indenture unless otherwise indicated.






























                                      - 7 -