SECURITIES AND EXCHANGE COMMISSION
              Washington, D.C.  20549

                  Schedule 13G

      Under the Securities Exchange Act of 1934

               (Amendment No. 3)

                Intl. Telecommunication Data Systems, Inc.
                (Name of Issuer)

                     Common
          (Title of Class of Securities)

                   46047F 10 4
                  (CUSIP Number)

                December 31, 1998
(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule 
is filed:

/x/ Rule 13d-1(b)   / / Rule 13d-1(c)   / / Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting 
person's initial filing on this form with respect to the subject class of 
securities, and for any subsequent amendment containing information which 
would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be 
deemed to be "filed" for the purposes of Section 18 of the Securities 
Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that 
section of the Act but shall be subject to all other provisions of the Act 
(however, see the Notes).

           (Continued on following page(s))


CUSIP No. 46047F 10 4
Schedule 13G

1
NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS 

        Dresdner RCM Global Investors LLC  94-3244780

2
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a)  [  ]                  (b)  [  ]

3
SEC USE ONLY

4
CITIZENSHIP OR PLACE OF ORGANIZATION

        Dresdner RCM Global Investors LLC - DE Limited Liability Co.

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

5 SOLE VOTING POWER             833,675

6 SHARED VOTING POWER           -0-

7 SOLE DISPOSITIVE POWER        1,255,875

8 SHARED DISPOSITIVE POWER      200

9
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

        1,256,075

10
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

11
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

        7.27%

12
TYPE OF REPORTING PERSON

        Dresdner RCM Global Investors LLC -IA,OO



Item 1(a) Name of Issuer:

        Intl. Telecommunication Data Systems, Inc.

Item 1(b) Address of Issuer's Principal Executive Offices:

        225 High Ridge Rd.
        Suite 205
        Stamford, CT  06905

Item 2(a) Name of Person Filing:

        Dresdner RCM Global Investors LLC

Item 2(b) Address of Principal Business Office or, if none, Residence:

        Four Embarcadero Center
        San Francisco, California  94111

Item 2(c) Citizenship:

        Dresdner RCM Global Investors LLC - DE Limited Liability Co.

Item 2(d) Title of Class of Securities:

        Common

Item 2(e) CUSIP Number:

        46047F 10 4

Item 3.  If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b), 
check whether the person filing is a:

        (e)  [X]  An investment adviser in accordance with 
        SECTIONS 240.13d-1(b)(1)(ii)(E).

Item 4.  Ownership.

        See responses to Items 5, 6, 7, 8, 9, and 11 of Cover Page.

Item 5.  Ownership of Five Percent or Less of a Class.

        If this statement is being filed to report the fact that as of the 
date hereof the reporting person has ceased to be the beneficial owner of 
more than five percent of the class of securities, check the following [  ].

Item 6.  Ownership of More than Five Percent on Behalf of Another Person.

        Not Applicable.

Item 7.  Identification and Classification of the Subsidiary Which Acquired 
the Security Being Reported on By the Parent Holding Company.

        Not Applicable.

Item 8.  Identification and Classification of Members of the Group.

        Not Applicable.

Item 9. Notice of Dissolution of Group.

        Not Applicable.

Item 10.  Certification.

        Not Applicable.

After reasonable inquiry and to the best of my knowledge and belief, I 
certify that the information set forth in this statement is true, complete 
and correct.

DRESDNER RCM GLOBAL INVESTORS LLC

By /s/ Susan C. Gause                 January 8, 1999
        Susan C. Gause
        Chief Operating Officer