Exhibit 5.1
                                January 25, 2002


C-COR.net Corp.
60 Decibel Road
State College, Pennsylvania  16801

               Re:  C-COR.net Corp. Registration Statement on Form S-3
                    --------------------------------------------------

Ladies and Gentlemen:

     We have acted as special counsel to C-COR.net Corp., a Pennsylvania
corporation (the "Company") in connection the preparation and filing with the
Securities and Exchange Commission (the "Commission") under the Securities Act
of 1933, as amended (the "Act"), of a Registration Statement on Form S-3 (the
"Registration Statement") relating to the registration under the Act of an
aggregate amount of up to $150,000,000 of one or more series of (i) debt
securities of the Company ("Debt Securities"), (ii) shares of common stock, $.05
par value per share, of the Company ("Common Stock"), (iii) shares of preferred
stock, without par value, of the Company ("Preferred Stock"), and (iv) warrants
to purchase Debt Securities, Common Stock, or Preferred Stock ("Warrants").

     In our capacity as counsel, we have examined originals or copies, certified
or otherwise identified to our satisfaction, of the Registration Statement and
all exhibits thereto. We have also examined and relied upon such corporate
records of the Company, and other agreements, documents and instruments, and
such certificates or comparable documents of public officials, officers and
representatives of the Company and other persons, and have made such inquiries
of such officers, representatives and other persons and have considered such
matters of law as we have deemed appropriate as the basis for the opinions
hereinafter set forth. In all cases, we have assumed the legal capacity and
competence of all natural persons, the genuineness of all signatures, the
authenticity of all documents submitted to us as originals and the conformity to
original documents of documents submitted to us as certified, conformed,
photostatic or facsimile copies and the accuracy and completeness of all
corporate records and other information made available to us by the Company.

     Based upon the foregoing and subject to the assumptions, exceptions,
limitations and qualifications set forth herein, we are of the opinion that:



January 25, 2002
Page 2


     1. Assuming that the Debt Securities and the indenture (and any
supplemental indenture) to be entered into in connection with the issuance of
such Debt Securities have been duly authorized, when (i) the Registration
Statement has become effective under the Act, (ii) an indenture and any
supplemental indenture relating to the Debt Securities have been duly
authorized, executed and delivered, (iii) the terms of the Debt Securities and
their issuance and sale have been duly established in accordance with the
applicable indenture and any applicable supplemental indenture relating to such
Debt Securities so as not to violate any applicable law or result in a default
under or breach of any agreement or instrument binding upon the Company and so
as to comply with any requirement or restriction imposed by any court or
governmental or regulatory body having jurisdiction over the Company, and (iv)
the Debt Securities have been duly executed and authenticated in accordance with
the applicable indenture and any applicable supplemental indenture relating to
such Debt Securities and duly issued and delivered by the Company in the manner
contemplated in the Registration Statement and any prospectus supplement
relating thereto, the Debt Securities (including any Debt Securities duly issued
(y) upon exchange or conversion of any shares of Preferred Stock that are
exchangeable or convertible into Debt Securities, or (z) upon exercise of any
Warrants exercisable for Debt Securities) will constitute valid and binding
obligations of the Company.

     2. When (i) the Registration Statement has become effective under the Act,
(ii) the shares of Common Stock have been duly and properly authorized for
issuance, and (iii) the shares of Common Stock have been duly issued, sold and
delivered as contemplated in the Registration Statement and any prospectus
supplement relating thereto, the shares of Common Stock (including any Common
Stock duly issued (x) upon the conversion or exchange of any Debt Securities
that are convertible or exchangeable into Common Stock, (y) upon the exchange
or conversion of any shares of Preferred Stock that are exchangeable or
convertible into Common Stock, (z) upon the exercise of any Warrants exercisable
for Common Stock), will be legally issued, fully paid and non-assessable.

     3. When (i) the Registration Statement has become effective under the Act,
(ii) the Preferred Stock has been duly and properly authorized for issuance and
an Articles of Amendment to the Amended Restated Articles of Incorporation of
the Company classifying the Preferred Stock and setting forth the terms thereof
has been filed, and (iii) the shares of Preferred Stock have been duly issued
and paid for in the manner contemplated in the Registration Statement and any
prospectus supplement relating thereto, the shares of Preferred Stock will be
legally issued, fully paid and non-assessable.

     4. Assuming that a warrant agreement relating to the Warrants (the "Warrant
Agreement") has been duly authorized, when (i) the Registration Statement has
become effective under the Act, (ii) the Warrant Agreement has been duly
executed and delivered, (iii) the terms of the Warrants and of their issuance
and sale have been duly established in conformity with the Warrant Agreement
relating to such warrants so as not to violate any applicable law or result in
default under or breach of any agreement or instrument binding upon the Company
and so as to comply with any requirement or restriction imposed by any court of
governmental or regulatory body having jurisdiction over the Company, and (iv)
the Warrants have been duly executed and countersigned in accordance with the
Warrant Agreement relating to such Warrants and issued and sold in the form and
in the manner contemplated in the Registration Statement and any



January 25, 2002
Page 3

prospectus supplement relating thereto, such Warrants will constitute valid and
binding obligations of the Company.

     The opinions set forth in paragraphs 1 and 4 are subject to the effect of
applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent
conveyance, fraudulent transfer, marshalling or similar laws affecting
creditors' rights and remedies generally; and general principles of equity,
including without limitation, concepts of materiality, reasonableness, good
faith and fair dealing (regardless of whether such enforceability is considered
in a proceeding in equity or at law).

     We express no opinion concerning the laws of any jurisdiction other than
the federal law of the United States of America and the Commonwealth of
Pennsylvania.

     We hereby consent to the sole use of this opinion as an exhibit to the
Registration Statement and to the use of our name under the heading "Legal
Matters" in the prospectus included therein. This opinion is not to be used,
circulated, quoted, referred to or relied upon by any other person or for any
other purpose without our prior written consent.

                                  Very truly yours,

                                  /s/ BALLARD SPAHR ANDREWS & INGERSOLL, LLP