Tollgrade Communications (TLGD) SC 13D/A TOLLGRADE COMMUNICATIONS / Starboard Value ownership change

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO

§ 240.13d-2(a)

(Amendment No. 10)1

Tollgrade Communications, Inc.

(Name of Issuer)

Common Stock, $ 0.20 Par Value

(Title of Class of Securities)

889542106

(CUSIP Number)

JEFFREY C. SMITH

STARBOARD VALUE LP

599 Lexington Avenue, 19th Floor

New York, New York 10022

(212) 845-7977

STEVEN WOLOSKY, ESQ.

OLSHAN GRUNDMAN FROME ROSENZWEIG & WOLOSKY LLP

Park Avenue Tower

65 East 55th Street

New York, New York 10022

(212) 451-2300

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

March 31, 2011

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box ¨.

Note:  Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits.  See § 240.13d-7 for other parties to whom copies are to be sent.

_______________

1              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 disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose 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).

CUSIP NO. 889542106

1	NAME OF REPORTING PERSON STARBOARD VALUE AND OPPORTUNITY FUND LTD
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION CAYMAN ISLANDS
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 965,199
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 965,199
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 965,199
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 7.4%
14	TYPE OF REPORTING PERSON CO

2

CUSIP NO. 889542106

1	NAME OF REPORTING PERSON STARBOARD VALUE LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 2,094,957
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 2,094,957
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,094,957
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 16.0%
14	TYPE OF REPORTING PERSON PN

3

CUSIP NO. 889542106

1	NAME OF REPORTING PERSON STARBOARD VALUE GP LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 2,094,957
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 2,094,957
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,094,957
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 16.0%
14	TYPE OF REPORTING PERSON OO

4

CUSIP NO. 889542106

1	NAME OF REPORTING PERSON STARBOARD PRINCIPAL CO LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 2,094,957
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 2,094,957
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,094,957
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 16.0%
14	TYPE OF REPORTING PERSON PN

5

CUSIP NO. 889542106

1	NAME OF REPORTING PERSON STARBOARD PRINCIPAL CO GP LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 2,094,957
	8	SHARED VOTING POWER - 0 -
	9	SOLE DISPOSITIVE POWER 2,094,957
	10	SHARED DISPOSITIVE POWER - 0 -
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,094,957
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 16.0%
14	TYPE OF REPORTING PERSON OO

6

CUSIP NO. 889542106

1	NAME OF REPORTING PERSON JEFFREY C. SMITH
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER - 0 -
	8	SHARED VOTING POWER 2,094,957
	9	SOLE DISPOSITIVE POWER - 0 -
	10	SHARED DISPOSITIVE POWER 2,094,957
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,094,957
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 16.0%
14	TYPE OF REPORTING PERSON IN

7

CUSIP NO. 889542106

1	NAME OF REPORTING PERSON MARK MITCHELL
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER - 0 -
	8	SHARED VOTING POWER 2,094,957
	9	SOLE DISPOSITIVE POWER - 0 -
	10	SHARED DISPOSITIVE POWER 2,094,957
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,094,957
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 16.0%
14	TYPE OF REPORTING PERSON IN

8

CUSIP NO. 889542106

1	NAME OF REPORTING PERSON PETER A. FELD
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) o   (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER - 0 -
	8	SHARED VOTING POWER 2,094,957
	9	SOLE DISPOSITIVE POWER - 0 -
	10	SHARED DISPOSITIVE POWER 2,094,957
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,094,957
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 16.0%
14	TYPE OF REPORTING PERSON IN

9

CUSIP NO. 889542106

The following constitutes Amendment No. 10 (“Amendment No. 10”) to the Schedule 13D filed by the undersigned.  This shall be deemed to amend and restate in their entirety Items 2, 3 and 5 and add to Items 6 and 7 of the Schedule 13D.  The primary purpose of amending the Schedule 13D is to report changes among the Reporting Persons as a result of a spin-off of Ramius’s Value and Opportunity business into a stand-alone and independent business managed by Starboard Value LP.  The spin-off became effective as of March 31, 2011.

Item 2. Identity and Background.

Item 2 is hereby amended and restated to read as follows:

(a)           This statement is filed by:

(i) Starboard Value and Opportunity Fund Ltd, a Cayman Islands exempted company (“Starboard V&O Fund”), with respect to the Shares directly and beneficially owned by it;

(ii) Starboard Value LP (“Starboard Value LP”), as the investment manager of Starboard V&O Fund and of certain managed accounts (the “Starboard Value LP Accounts”);

(iii) Starboard Value GP LLC (“Starboard Value GP”), as the general partner of Starboard Value LP;

(iv) Starboard Principal Co LP (“Principal Co”), as a member of Starboard Value GP;

(v) Starboard Principal Co GP LLC (“Principal GP”), as the general partner of Principal Co;

(vi) Jeffrey C. Smith, as a member of Principal GP and as a member of each of the Management Committee of Starboard Value GP and the Management Committee of Principal GP;

(vii) Mark Mitchell, as a member of Principal GP and as a member of each of the Management Committee of Starboard Value GP and the Management Committee of Principal GP; and

(viii) Peter A. Feld, as a member of Principal GP and as a member of each of the Management Committee of Starboard Value GP and the Management Committee of Principal GP.

Each of the foregoing is referred to as a “Reporting Person” and collectively as the “Reporting Persons.”  Each of the Reporting Persons is party to that certain Joint Filing Agreement, as further described in Item 6.  Accordingly, the Reporting Persons are hereby filing a joint Schedule 13D.

(b)           The address of the principal office of each Starboard Value LP, Starboard Value GP, Principal Co, Principal GP, and Messrs. Smith, Mitchell and Feld is 599 Lexington Avenue, 19th Floor, New York, New York 10022.  The address of the principal office of Starboard V&O Fund is c/o Citco Fund Services (Cayman Islands) Limited, Regatta Office Park, Windward 1, 2nd Floor, PO Box 31106, Grand Cayman KY1-1205, Cayman Islands.  The officers and directors of Starboard V&O Fund and their principal occupations and business addresses are set forth on Schedule A and are incorporated by reference in this Item 2.

10

CUSIP NO. 889542106

(c)           The principal business of Starboard V&O Fund is serving as a private investment fund.  Starboard V&O Fund has been formed for the purpose of making equity investments and, on occasion, taking an active role in the management of portfolio companies in order to enhance shareholder value.  Starboard Value LP provides investment advisory and management services and acts as the investment manager of Starboard V&O Fund.  Starboard Value LP also serves as the investment manager of the Starboard Value LP Accounts and has sole voting and dispositive power over the Shares held by the Starboard Value LP Accounts.  The principal business of Starboard Value GP is providing a full range of investment advisory, pension advisory and management services and serving as the general partner of Starboard Value LP.  The principal business of Principal Co is providing investment advisory and management services.  Principal Co is a member of Starboard Value GP.  Principal GP serves as the general partner of Principal Co.  Messrs. Smith, Mitchell and Feld serve as members of Principal GP and the members of each of the Management Committee of Starboard Value GP and the Management Committee of Principal GP.

(d)           No Reporting Person, nor any person listed on Schedule A, annexed hereto, has, during the last five years, been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

(e)           No Reporting Person, nor any person listed on Schedule A, annexed hereto, has, during the last five years, been party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f)           Messrs. Smith, Mitchell and Feld are citizens of the United States of America.  The citizenship of the persons listed on Schedule A is set forth therein.

Item 3. Source and Amount of Funds or Other Consideration.

Item 3 is hereby amended and restated to read as follows:

The Shares purchased by Starboard V&O Fund were purchased with working capital (which may, at any given time, include margin loans made by brokerage firms in the ordinary course of business) in open market purchases.  The aggregate purchase price of the 965,199 Shares beneficially owned by Starboard V&O Fund is approximately $4,964,003, excluding brokerage commissions.

The aggregate purchase price of the 1,129,758 Shares held in the Starboard Value LP Accounts is approximately $6,460,545, excluding brokerage commissions.  The Shares held in the Starboard Value LP Accounts were acquired with the working capital of entities managed by Starboard Value LP.

Item 5. Interest in Securities of the Issuer.

Item 5 is hereby amended and restated to read as follows:

The aggregate percentage of Shares reported owned by each person named herein is based upon 13,092,152 Shares outstanding, as of March 22, 2011, which is the total number of Shares outstanding as reported in the Issuer’s Definitive Proxy Statement, filed with the Securities and Exchange Commission on April 1, 2011.

11

CUSIP NO. 889542106

A. Starboard V&O Fund

(a) As of the close of business on April 1, 2011, Starboard V&O Fund beneficially owned 965,199 Shares.

Percentage: Approximately 7.4%.

(b) 1. Sole power to vote or direct vote: 965,199

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 965,199

4. Shared power to dispose or direct the disposition: 0

(c) Starboard V&O Fund has not entered into any transactions in the Shares during the past 60 days.

B. Starboard Value LP

(a) As of the close of business on April 1, 2011, 1,129,758 Shares were held in the Starboard Value LP Accounts.  Starboard Value LP, as the investment manager of Starboard V&O Fund, may be deemed the beneficial owner of the 965,199 Shares owned by Starboard V&O Fund.

Percentage: Approximately 16.0%.

(b) 1. Sole power to vote or direct vote: 2,094,957

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 2,094,957

4. Shared power to dispose or direct the disposition: 0

(c) Starboard Value LP has not entered into any transactions in the Shares during the past 60 days.

C. Starboard Value GP

(a) Starboard Value GP, as the general partner of Starboard Value LP, may be deemed the beneficial owner of the (i) 965,199 Shares owned by Starboard V&O Fund and (ii) 1,129,758 Shares held in the Starboard Value LP Accounts.

Percentage: Approximately 16.0%.

(b) 1. Sole power to vote or direct vote: 2,094,957

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 2,094,957

4. Shared power to dispose or direct the disposition: 0

(c) Starboard Value GP has not entered into any transactions in the Shares during the past 60 days.

12

CUSIP NO. 889542106

D. Principal Co

(a) Principal Co, as a member of Starboard Value GP, may be deemed the beneficial owner of the (i) 965,199 Shares owned by Starboard V&O Fund and (ii) 1,129,758 Shares held in the Starboard Value LP Accounts.

Percentage: Approximately 16.0%.

(b) 1. Sole power to vote or direct vote: 2,094,957

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 2,094,957

4. Shared power to dispose or direct the disposition: 0

(c) Principal Co has not entered into any transactions in the Shares during the past 60 days.

E. Principal GP

(a) Principal GP, as the general partner of Principal Co, may be deemed the beneficial owner of the (i) 965,199 Shares owned by Starboard V&O Fund and (ii) 1,129,758 Shares held in the Starboard Value LP Accounts.

Percentage: Approximately 16.0%.

(b) 1. Sole power to vote or direct vote: 2,094,957

2. Shared power to vote or direct vote: 0

3. Sole power to dispose or direct the disposition: 2,094,957

4. Shared power to dispose or direct the disposition: 0

(c) Principal GP has not entered into any transactions in the Shares during the past 60 days.

F. Messrs. Smith, Mitchell and Feld

(a) Each of Messrs. Smith, Mitchell and Feld, as a member of Principal GP and as a member of each of the Management Committee of Starboard Value GP and the Management Committee of Principal GP, may be deemed the beneficial owner of the (i) 965,199 Shares owned by Starboard V&O Fund and (ii) 1,129,758 Shares held in the Starboard Value LP Accounts.

Percentage: Approximately 16.0%.

(b) 1. Sole power to vote or direct vote: 0

2. Shared power to vote or direct vote: 2,094,957

3. Sole power to dispose or direct the disposition: 0

4. Shared power to dispose or direct the disposition: 2,094,957

(c) None of Messrs. Smith, Mitchell or Feld has entered into any transactions in the Shares during the past 60 days.

To the best of the Reporting Persons’ knowledge, none of the persons listed on Schedule A, who are not also Reporting Persons, beneficially owns any securities of the Issuer.

13

CUSIP NO. 889542106

(d) No person other than the Reporting Persons is known to have the right to receive, or the power to direct the receipt of dividends from, or proceeds from the sale of, the Shares.

(e) Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

Item 6 is hereby amended to add the following:

On April 4, 2011, the Reporting Persons entered into a Joint Filing Agreement in which the Reporting Persons agreed to the joint filing on behalf of each of them of statements on Schedule 13D with respect to the securities of the Issuer to the extent required by applicable law.  The Joint Filing Agreement is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

Item 7. Material to be Filed as Exhibits.

Item 7 is hereby amended to add the following exhibits:

99.1 Joint Filing Agreement by and among Starboard Value and Opportunity Fund Ltd, Starboard Value LP, Starboard Value GP LLC, Starboard Principal Co LP, Starboard Principal Co GP LLC, Jeffrey C. Smith, Mark Mitchell and Peter A. Feld, dated April 4, 2011.

99.2 Power of Attorney for Jeffrey C. Smith, Mark Mitchell and Peter A. Feld, dated April 4, 2011.

14

CUSIP NO. 889542106

SIGNATURES

After reasonable inquiry and to the best of his knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated:  April 4, 2011

STARBOARD VALUE AND OPPORTUNITY FUND LTD By: Starboard Value LP,        its investment manager   STARBOARD VALUE LP By: Starboard Value GP LLC,        its general partner STARBOARD VALUE GP LLC By: Starboard Principal Co LP,        its member   STARBOARD PRINCIPAL CO LP By: Starboard Principal Co GP LLC,        its general partner   STARBOARD PRINCIPAL CO GP LLC

By:	/s/ Jeffrey C. Smith
	Name:	Jeffrey C. Smith
	Title:	Authorized Signatory

/s/ Jeffrey C. Smith 

Jeffrey C. Smith

Individually and as attorney-in-fact for

Mark Mitchell and Peter A. Feld

15

CUSIP NO. 889542106

SCHEDULE A

Directors and Officers of Starboard Value and Opportunity Fund Ltd

Name and Position	Principal Occupation	Principal Business Address	Citizenship
Patrick Agemian Director	Director of Global Funds Management, Ltd.	PO Box 10034, Harbour Place 2nd Floor 103 South Church Street Grand Cayman Cayman Islands, KY1-1001	Canada
Mark Mitchell Director*
Don Seymour Director	Managing Director of dms Management Ltd.	dms Management Ltd. dms House, 20 Genesis Close P.O. Box 31910 Grand Cayman Cayman Islands, KY1-1208	Cayman Islands

* Mr. Mitchell is a Reporting Person and, as such, the information with respect to Mr. Mitchell called for by Item 2 of Schedule 13D is set forth therein.