OPINION AND ORDER

I. INTRODUCTION

Rates Technology Inc. (“RTI”) brings this action against Broadvox Holding Company, LLC, its named subsidiary, Cypress Communications Operating Company, LLC, and its unnamed subsidiaries or affiliates, ABC Companies 1 to 10 (collectively, “Broadvox”), for infringing two of RTFs telecommunications patents: United States Patent No. 5,425,085 (the “'085 Patent”) and United States Patent No. 5,519,-769 (the “'769 Patent”).1

On December 27, 2013, the Court held a Markman hearing. The parties have agreed upon the meaning of three terms in claim 1 of the '085 Patent and two terms in claim 1 of the '769 Patent.2 The parties dispute the meaning of nine terms in claim 1 of the '085 Patent and five terms in claim 1 of the '769 Patent.3 For reference, I have included a list of the constructions I have adopted at the end of this Opinion.4

II. BACKGROUND

A. The Invention

RTI has provided products and services in the telecommunications field for thirty years.5 RTI designs and manufactures technologies including private pay telephones, call cost rate chips, and least-cost-routing chips.6 On June 13, 1995, the Patent and Trademark Office (“PTO”) issued the '085 Patent, designating RTI as the *313sole assignee.7 The claimed invention relates to the routing of calls based on cost.8 Broadvox Holding provides IP-based information services to approximately three hundred wholesale carriers, businesses, and enterprise retail customers.9 On May 21,1996, the PTO issued the '769 Patent to RTI.10 The claimed invention relates to a method for updating a database in a telephone routing system.11 In two 1998 decisions, Judge William Young of the District Court of Massachusetts construed several of the claims disputed here.12 Several years later, the patents were returned to the PTO for reexamination, where the claims were reconsidered in light of prior art.13 While the reexaminations did not affect claim 1 of the '769 Patent, RTI added limitations to claim 1 of the ’085 Patent to overcome the prior art.14

B. Claim Language

The full text of claim 1 of the '085 Patent, with the disputed phrases emphasized, follows:

A device for routing telephone calls along a least cost route originating from a first telephone to a second telephone having an associated telephone number via a network having a plurality of alternate communication switch paths corresponding to different carriers which can be chosen to route the call and normally providing a current to said first telephone when said first telephone is in use, comprising:

[I] a housing forming an enclosure and comprising first jack means for connection to said first telephone, and second jack means for connection to said network;

[ii] switch means operatively connected to said first jack means for disconnecting said first telephone from said network during routing of a telephone call from said first telephone;

[in] means operatively connected to said switch means for generating a current through said switch means to the first telephone corresponding to a current provided by said network, w hen the first telephone is disconnected from said network by said switch means;

[iv] database means for storing billing rate parameters for determining a least cost communication path for call corresponding to said telephone number;

[v] means operatively connected to said switch means for detecting and storing said telephone number originating from the first telephone;

[vi] means for addressing said database means for identifying a plurality of communication switch *314paths to said second telephone and the cost rate of each path;

[vii] means actuated subsequent to the detection of said telephone number originating from said first telephone for comparing the cost rate of each path so as to determine a least cost route; and

[viii] means operatively connected to said switch means and said second jack means for generating a number sequence corresponding to a desired carrier so that said call is routed through said second jack means to the selected communication path and carrier to establish a switched connection between said first telephone and said second telephone.15

The full text of claim 1 of the '769 Patent, with the disputed phrases emphasized, follows:

A method for updating a database that stores billing rate parameters for a call rating device used for cost determinations for a calling station, comprising the steps of:

[I] connecting at a predetermined time and date via a data transfer line the call rating device to a rate provider having billing rate parameters for a plurality of calling stations;

[ii] transmitting over the data transfer line indicia identifying the call rating device and the date and time of the last update of the billing rate parameters;

[iii] verifying if billing parameters should be updated; and

[iv] transmitting from the rate provider to the call rating device the updated billing rate parameters when the rate provider determines that an update is required.16

The parties agree on the construction of the following phrases:

TABLE 117

'085 Patent, Claim 1

Term/Phrase Agreed Upon Construction

1. “device” The term should not be a limitation of the claim.

2. “first jack means for connection to said first First jack for connection to said first telephone,

telephone”

3. “second jack means for connection to said Second jack for connection to said network, network”

'769 Patent, Claim 1

Term/Phrase Agreed Upon Construction

1. “a data transfer line” a data transfer line (or path to transfer data)

2. “indicia identifying the call rating device and the indicia identifying call rating device and the date date and time of the last update of the billing rate and time of the last update of the billing rate parameters” parameters.

The parties dispute the construction of the following phrases:

*315TABLE 218

[[Image here]]

*316[[Image here]]

*317[[Image here]]

III. APPLICABLE LAW

Analysis of a patent infringement claim involves two steps: (1) construction of the terms of the asserted claims and (2) determination of whether the accused device infringes the claims, as construed.19 Claim construction is a question of law,20 the purpose of which is to determine what is covered by an asserted claim. In other words, “[t]he construction of claims is simply a way of elaborating the normally terse claim language in order to understand and explain, but not to change, the scope of the claims.”21

*318 The Federal Circuit has made clear that "there is no magic formula or catechism for conducting claim construction." 22 Thus, courts must be mindful that "applying [the substantive precepts of patent claim interpretationj to the facts of a case can be ... perplexing, particularly where precepts can be in opposition to one another and district judges cannot always tell which one(s) apply in a particular case." 23 As such, the Federal Circuit has provided district courts with some guidance:

[T]he ordinary and customary meaning of a claim term is the meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention, i.e., as of the effective filing date of the patent application.... [This inquiry] provides an objective baseline from which to begin claim interpretation .... Importantly, the person of ordinary skill in the art is deemed to read the claim term not only in the context of the particular claim in which the disputed term appears, but in the context of the entire patent, including the specification.24

To determine how a person skilled in the art understands a disputed claim term, courts should look to publicly available sources, including intrinsic evidence&emdash;such as “the words of the claims themselves, the remainder of the specification, the prosecution history”&emdash;and “extrinsic evidence concerning relevant scientific principles, the meaning of technical terms, and the state of the art.”25

A. Intrinsic Evidence

The Federal Circuit views intrinsic evidence as “a more rehable guide to the meaning of a claim term than are extrinsic sources.”26 Thus, district courts should use the intrinsic record as “the primary tool to supply the context for interpretation of disputed claim terms.”27

1. Claim Language

Although there is no rigid formula to claim construction, “[j]udicial interpretation must begin with and remain focused upon the ‘words of the claims themselves ... to define the scope of the patented invention.’ ”28 On occasion, “the ordinary meaning of claim language as understood by a person of skill in the art” will be so apparent from the claim language itself that no further inquiry is needed.29 However, even when the terms in a claim are self-explanatory, “[t]he context in which a term is used in the asserted claim can be highly instructive.”30

2. The Specification

In addition to the claim itself, a patent is required by statute to “contain a written *319description of the invention .31 This description — known as the specification32 —includes: “an abstract of the invention; a description of the invention’s background; a summary of the invention; patent drawings; and a detailed description that discusses preferred embodiments of the invention.”33 The Federal Circuit has said that specifications are “always highly relevant to the claim construction analysis” and therefore “claims must be read in view of the specification, of which they are a part.”34

However, courts must be mindful thát while “using the specification to interpret the meaning of a claim” is permissible, “importing limitations from the specification into the claim” is not.35 Because words of the claim alone “define the scope of the right to exclude,”36 the specification should generally be used to limit a claim only:

(1) if the claim “explicitly recite[s] a term in need of definition”; or (2) if the specification unambiguously defines a term, i.e., if “a patent applicant has elected to be a lexicographer by providing an explicit definition in the specification for a claim term.”37

Even then, “there will still remain some cases in which it will be hard to determine whether a person of skill in the art would understand the embodiments to define the outer limits of the claim term or merely to be exemplary in nature.”38

3. Prosecution History

The prosecution history of a patent is part of the “intrinsic evidence” and “consists of the complete record of the proceedings before the PTO and includes the prior art cited during the examination of the patent.”39 “[Bjecause the prosecution history represents an ongoing negotiation between the PTO and the applicant, rather than the final product of that negotiation, it often lacks the clarity of the specification and thus is less useful for claim construction purposes.”40 Nonetheless, “[ljike the specification, the prosecution history provides evidence of how the PTO and the inventor understood the patent,” and accordingly, “can often inform the meaning of the claim language.”41

Furthermore, the prosecution history “may be given substantial weight in construing a term where that term was added by amendment.”42 This is because *320changes made to the claim terms during the prosecution history “demonstrare] how the inventor understood the invention and whether the inventor limited the invention in the course of prosecution, making the claim scope narrower than it would otherwise be.”43 As such, “[w]hen the patentee unequivocally and unambiguously disavows a certain meaning to obtain a patent, the doctrine of prosecution history disclaimer narrows the meaning of the claim consistent with the scope of the claim surrendered.”44 The doctrine applies even where the patentee’s statements are not “necessary or persuasive” to the PTO.45

B. Extrinsic Evidence

The extrinsic record “consists of all evidence external to the patent and prosecution history, including expert and inventor testimony, dictionaries, and learned treatises.”46 Although the Federal Circuit allows district courts to “rely on extrinsic evidence,” it views “extrinsic evidence in general as less reliable than the patent and its prosecution history in determining how to read claim terms.”47

“Generally, a patent’s intrinsic record does not warrant consideration of extrinsic evidence.”48 “Where a patent’s claims, written description, and prosecution history are complete and unambiguous, a court need not resort to extrinsic evidence such as treatises, technical references, or expert testimony.”49 But “[w]here the intrinsic record leaves ambiguities and unresolved questions ... a court may consider extrinsic evidence, including expert testimony.”50

The Federal Circuit has noted that “the decision as to the need for and use of experts is within the sound discretion of the district court.”51 It is unhelpful if an expert “simply recites how [he] would construe [a term] based on his own reading of the specification.”52 On the other hand, expert reports and testimony can help the court by:

[providing] background on the technology at issue, [explaining] how an invention works, [ensuring] that the court’s understanding of the technical aspects of the patent is consistent with that of a person of skill in the art, or [establishing] that a particular term in the patent or the prior art has a particular meaning in the pertinent field.53

With this in mind, “a court should discount any expert testimony ‘that is clearly at odds with the claim construction mandated by the claims themselves, the written description, and the prosecution history, in *321other words, with the written record of the patent.’ ”54 “Even if the judge permissibly decide[s] to hear all the possible evidence before construing the claim, the expert testimony, which [is] inconsistent with the specification and file history, should [be] accorded no weight.”55

C. Means-Plus-Function

“Section 112(f) [of Title 35] allows patentees to put structural details into the specification and build into the literal coverage of the claim a certain scope for equivalents in performing a defined function.” 56 Section 112(f) states:

An element in a claim for combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.57

This form of claiming, known as means-plus-function claiming, applies to “purely functional limitations that do not provide the structure that performs the recited function.”58 It “represents a quid pro quo by permitting inventors to use a generic means expression for a claim limitation provided that the specification indicates what structure(s) constitute(s) the means.”59

“[W]hether the limitation in question should be regarded as a means-plus-function limitation, like all claim construction issues, is a question of law for the court, even though ... evidence from experts may be relevant.”60 As with any claim term, a court examines “the words of the claims themselves, the written description, the prosecution history, and any relevant extrinsic evidence.”61 “[W]hether claim language invokes Section 112, II6 depends on how those skilled in the art would understand the structural significance of that claim language, assessed against the presumptions that flow from a drafter’s choice to employ or not employ the term ‘means.’ ”62

The Federal Circuit has established “two guidelines for determining whether the special rules of claim construction set forth in Section 112, ¶ 6 apply to a given claim limitation.”63 First, “use of the word ‘means’ creates a rebuttable presumption that the drafter intended to invoke Section 112, ¶ 6.”64 A challenger may rebut the presumption where a claim re*322cites a function “but then goes on to sufficient structure, material, or acts within the claim itself to perform entirely the recited function.”65 In such a case, “the claim is not in means-plus-function format even if the claim uses the term means.”66

Conversely, “[i]f a claim term does not use the word ‘means,’ we presume that means-plus-function claiming does not apply.”67 “[T]he presumption flowing from the absence of the term ‘means’ is a strong one that is not readily overcome.”68 In deciding whether a challenger has rebutted the presumption, “the focus remains on whether the claim as properly construed recites sufficiently definite structure to avoid the ambit of § 112, ¶ 6.”69 The Federal Circuit requires only that “the claim term be used in common parlance or by ordinarily skilled artisans to designate sufficiently definite structure, ‘even if the term covers a broad class of structures.’ ”70 “If, however, the claim term recites a function without reciting sufficient structure for performing that function, the presumption falls and means-plus-function claiming applies.”71

Construction of a means-plus-function limitation involves two steps. “First, the court must determine the claimed function.”72 “Second, the court must identify the corresponding structure in the written description of the patent that performs the function.”73 “A structure disclosed in the specification qualifies as a ‘corresponding structure’ if the specification or the prosecution history clearly links or associates that structure to the function recited in the claim.”74

D. Indefiniteness

“Whether a claim complies with the definiteness requirement of 35 U.S.C. § 112 ¶ 2 is a matter of claim construction.” 75 Section 112, ¶ 2 states:

The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.76

Under this section, the inventor has a duty to “inform the public of the bounds of the protected invention, i.e., what subject matter is covered by the exclusive rights of the patent.”77 An inventor’s failure to “particularly point[ ] out and distinctly claim [ ]” the subject matter of her invention renders the claim invalid.78

*323Patents issued by the PTO enjoy a presumption of validity,79 and so indefiniteness must be proved by clear and convincing evidence.80 Whether a claim is indefinite is a question of law,81 although “[e]xpert testimony may be helpful in making this determination.”82 “A claim is definite if one skilled in the art would understand the bounds of the claim when read in light of the specification.”83 “A claim is not indefinite merely because it is difficult to construe.”84 To be indefinite, it must be such that “no narrowing construction can properly be adopted” to interpret the claim.85

If a means-plus-function limitation lacks a “structure disclosed in the specification to perform those functions, the claim limitation would lack specificity, rendering the claim as a whole invalid for indefiniteness.”86 A structure disclosed in the specification qualifies as a “corresponding structure” if the specification or the prosecution history “clearly links or associates that structure to the function recited in the claim.”87 “Even if the specification discloses a ‘corresponding structure,’ the disclosure must be adequate ... [to] show[ ] what is meant by that [claim] language.”88 “[T]he testimony of one of ordinary skill in the art cannot supplant the total absence of structure from the specification.”89

IV. DISCUSSION

A. General Claim Construction Issues

At the Markmcm hearing and in their briefs, the parties disagreed on several claim construction issues. Because the issues pertain to claim construction in general, I will address them before construing the individual terms.

1. RTI’s Expert

Broadvox argues that the Court should not consider the declaration of RTFs expert, Bradley Walton.90 First, Broadvox objects that Walton’s opinions are conclusory and contradict the intrinsic record.91 RTI responds that Walton reviewed the relevant claims, specification, and prosecution history to form his opinions.92 RTI notes that Walton is an electrical engineer in the telecommunications field, i.e., a person of ordinary skill in the art.93 Broadvox’s objections are overruled. Expert testimony may be useful to the *324Court in construing RTFs claims.94 If I find that a construction proposed by Walton contradicts the intrinsic evidence, I will simply discount it.

Second, Broadvox argues that Walton’s opinion is irrelevant because he failed to examine the entire prosecution history, specifically the reexaminations of the patents-in-suit.95 But at the Markman hearing, Mr. Spencer&emdash;counsel for RTI&emdash;rep-resented that he had personal knowledge that Walton reviewed “the entire prosecution history.”96 Thus, I will consider Walton’s opinions, including his determination of whether means-plus-function applies to certain terms.

2. Prior Judicial Construction of Claim Terms

The parties next disagree on the precedential effect of the MediaCom cases, in which Judge Young construed several of the claim terms at issue here. Broadvox contends that this Court is bound by the prior constructions under stare decisis.97 RTI urges this Court not to follow the MediaCom opinions, given that they were interlocutory and decided prior to the reexaminations.98 While I am certainly not bound by the MediaCom opinions, I find them persuasive.99 As I stated at the Markman hearing:

RTI was [before Judge Young in the MediaCom cases] and had a full and fair opportunity to litigate. It sounds like estoppel almost.... [RTI] litigated that very claim term fully, completely, and the Court spent a lot of time on it, had this expert, made a record, issued two decisions. That’s pretty persuasive to me.100

Moreover, as Broadvox notes, “the Media-Com cases were decided before the subsequent reexaminations, where RTI was forced to overcome new prior art.”101 Thus, the prior constructions are more favorable to RTI, than they would be today.

3. Effect of Prosecution History

Next, RTI argues that, for purposes of claim construction, it is not bound by statements it made to the PTO Board of Appeals.102 RTI cites no case law to support its assertion, and I see no reason why RTI’s statements to the PTO Appeals Board should not give rise to a prosecution disclaimer where they “unequivocally and unambiguously disavow[ ] a certain meaning ... ”103

Finally, RTI argues that prosecution history statements are never relevant to the determination of whether “means-plus-*325function” claiming applies.104 RTI cites only to Robinson v. Cannondale Corporation, where the Federal Circuit found that means-plus-function did not apply to a claim that used the word “means” because it recited sufficient structure to perform the function.105 In that case, the court did not need to examine the prosecution history because the claim language clearly recited the claimed structure.106 This does not mean that prosecution history is never relevant to the determination of whether means-plus-function applies. To the contrary, under Federal Circuit law, it generally is.107

B. Disputed Constructions for Claim 1 of the '085 Patent

1. “a housing forming an enclosure and comprising”

RTI argues that “a housing forming an enclosure and comprising” should be construed as “one or more housings forming one or more enclosures.”108 Bro-advox proposes “a unitary physical structure that includes a first jack for connection to a first telephone and a second jack for connection to a network.”109 The difference between the proposed constructions is whether both the first and second jack means must be contained in a single housing.

I begin with the intrinsic evidence. The plain language of the claim is consistent with the specification and prosecution history and indicates a single housing enclosing both the first and second jack means. The claim refers to “[a] housing forming an enclosure and comprising first jack means for connection to said second jack means ...”110 The patent’s abstract states, “[t]he device components are contained in the enclosure.”111 Figure 7 illustrates a single housing forming an enclosure connected to a first jack means and a second jack means.112 Finally, other parts of the specification use similar language, such as “[a] housing forms an enclosure and has jacks mounted on the housing ... [a] first jack interconnects to the phone side of the phone line and a second jack interconnects to the network side of the *326phone line.”113 Broadvox agrees with RTI, however, that the claimed device can have more than one “housing forming an enclosure.”114 Therefore, I define “a housing forming an enclosure” to mean “a unitary physical structure that includes a first jack for connection to a first telephone and a second jack for connection to a network. A claimed device may have more than one housing forming an enclosure, as defined above.”

2. “switch means operatively connected to said first jack means for disconnecting said first telephone from said network during routing of a telephone call from said first telephone”

The parties disagree on whether “switch means” is a means-plus-function limitation governed by Section 112(f). In MediaCom I, Judge Young ruled that it is not, reasoning:

Although the switch means element employs “means of_ing” language, it is not a means-plus-function claim, because it describes the structure that supports the disconnecting function (i.e. a switch or switches). Not only is the structure named, but it is described as connected to an adjacent structure, the first jack. Because this element of claim 1 recites a definite structure, it is not a means-plus-function claim element.115

In construing “switch means,” Judge Young observed that “[a]lthough the switch means claim element is not limited by the structure shown in the specification, the specification nevertheless informs construction of the terms in the claim.”116 He concluded that “[n]o special definition appears in the specification to indicate that the words ‘switch’ or ‘disconnect’ are to be understood in any way other than their ordinary meanings.”117 At the Markman hearing, Broadvox conceded that the subsequent reexaminations did not change the claim language.118 Thus, I see no reason why MediaCom I should not control and therefore conclude that this phrase is not governed by the means-plus-function limitation of Section 112(b). I define the phrase as: “switch operatively connected to said first jack for disconnecting said first telephone from said network during routing of a telephone call from said first telephone.”

3. “disconnecting”

Within the “switch means” phrase, the parties dispute the meaning of the word “disconnecting.” Again, the Media-Com decisions are instructive. In

MediaCom II, Judge Young construed “disconnecting” to mean, “the interruption&emdash;the breaking or opening&emdash;of the electrical circuit between the telephone jack and the network.”119 Broadvox urges this construction and RTI offers no good reason why I should not adopt it.120 Thus, *327I construe “disconnecting” as “the interruption — the breaking or opening — of the electrical circuit between the telephone jack and the network.”

4. & 5. “means operatively connected to said switch means for generating a current through said switch means to the first telephone corresponding to a current provided by said network, w hen the first telephone is disconnected from said network to said switch means”121

The parties again disagree on whether the phrase is a “means-plus-function” limitation.122 The court in Media-Com I answered as follows:

As a preliminary matter, this Court construes the generating means element of the claim as a means-plus-function element because it describes no particular structure for performing the function of generating a current corresponding to a current provided by the network.123

The court then looked to the specification to find a description of the structure that generates current.124 After examining the intrinsic evidence, the court concluded that “claim 1 presents questions that are sufficiently complex and technical that the court would be remiss to impose its lay understanding on this patent claim without the benefit of expert guidance.”125 In Me-diaCom II, the court returned to the phrase. After considering the testimony of RTI’s expert, Stephen Burns, the court construed the phrase as “an intermediate element that conditions or regulates electrical power from a more distant source so that it corresponds to the current that would otherwise have been provided directly by the telephone network, and passes the current through the switch to power the telephone.”126

RTI argues that even if the term is a means-plus-function limitation, Walton opined that “current source is the level of detail that the artisan would need to know what performs the function.”127 But as I said at the Markman hearing, Walton may not add language to the claim.128 Moreover, Judge Young construed the term with the benefit of RTFs previous expert. I therefore adopt Judge Young’s construction.129 I construe “means operatively connected ... switch means” as “an intermediate element that conditions or regulates electrical power from a more distant source so that it corresponds to the current that would otherwise have been provided directly by the telephone network, and passes the current through the switch to power the telephone.”

6. “means operatively connected to said switch means for detecting and storing said telephone number originating from the first telephone”

Once again, the parties debate whether this term is a means-plus-function limitation. Because the term uses the word “means,” there is a presumption that *328Section 112(F) applies.130 To rebut the presumption, RTI contends that “the artisan understands the terms ‘detecting’ and ‘storing’ as describing or defining a class of logic operations (i.e., structures) that detect and store.” 131 RTI urges that the phrase be construed as “logic operatively connected to a switch for detecting and storing a telephone number originating from the telephone.”132 RTI explains that “logic” refers to a “software program.”133 As the Federal Circuit has held:

[B]ecause general purpose computers can be programmed to perform very different tasks in very different ways, simply disclosing a computer as the structure designated to perform a particular function does not limit the scope of the claim to the corresponding structure, material, or acts that perform the function, as required by Section 112(f).134

Here, “logic” refers to no structure. Because RTI has engaged in “pure functional claiming,” Section 112(f) applies.135

The first step in construing a means-plus-function limitation is to “determine the claimed function.”136 Because the parties urge no particular meaning of the words used to recite the function, the Court gives them their ordinary meaning.137 Thus, looking only at the language of the claim without narrowing its scope, I construe the function as “detecting and storing said telephone number originating from the first telephone.”

Next, “the court must identify the corresponding structure in the written description of the patent that performs the function.”138 Broadvox and RTI surprisingly cite to the same sections of the specification for the structure, column 4 lines 40-43, which states, “[t]he dial tone detect circuit 86 connects to the line coming from the polarity guard 42 and connects to the line detector 40. The DTMF tone detector 88 detects the tones generated from the first phone.”139 Based on a reading of the full specification, the DTMF tone detector (88) detects and saves any digit it detects, other than the pound sign.140

Broadvox further notes that during the '085 Patent reexamination, RTI urged that the phrase be construed as a means-plus-function element and identified the structure as “Ref No. 88, Col. 4, lines 40-43, Fig. 2.”141 Based on the specification and prosecution history, I define the function as “detecting and storing said telephone number originating from the first telephone.” I construe the corresponding structure as described in column 4 lines 40-43 and as displayed in Figure 2. The dial tone detect circuit (86) connects to the line coming from the polarity guard (42) and connects to the line detector (40). The DTMF tone detector (88) detects and *329saves tones generated from the first phone.

7. “means for addressing said database means for identifying a plurality of communication switch paths to said second telephone and the cost rate of each path”

The term “means” gives rise to a presumption that Section 112(f) applies.142 Despite the presumption, RTI argues that the artisan understands the term “database” as connoting sufficient structure.143 As such, RTFs proposed construction for the term is “logic for addressing said database means for identifying a plurality of communication switch paths to said second telephone and the cost rate of each path.”144 However, “[i]t is not enough for the patentee simply to state or later argue that persons of ordinary skill in the art would know what structures to use to accomplish the claimed function.”145 Because the claim language itself provides no structure, Section 112(f) applies.

First, because the parties urge no particular meaning of the words that recite the function, the Court gives them their ordinary meaning. Thus, the claimed function is “addressing a database that identifies a plurality of communication switch paths to said second telephone and the cost rate of each path.”

Second, the corresponding structure is the algorithm disclosed in the specification column 6 lines 7-47 and Figure 5.146 In the reexamination, RTI identified the structure as “Ref. No. 50, Col. 6 lines 2-30, Fig. 5.”147 However, column 6 lines 7-47 recites the entire structure required to perform the function.

Based on the specification and prosecution history, I construe the phrase to perform the function of “addressing a database that identifies a plurality of communication switch paths to said second telephone and the cost rate of each path.” The corresponding structure is the algorithm disclosed in the specification at column 6 lines 7-47 and Figure 5.

8. “means actuated subsequent to the detection of said telephone number originating from said first telephone for comparing the cost rate of each path so as to determine a least cost route”

As with phrases 6 and 7, this phrase uses the word “means.” By arguing that a skilled artisan “understands the phrase ... to mean comparing logic actuated subsequent to the detection of said telephone number originating from a first telephone for comparing the cost rate of each path so as to determine a least cost route,” RTI again fails to rebut the presumption that Section 112(f) applies.148 “Comparing logic” appears nowhere in the claim language. Thus, “means actuated” is a means-plus-function limitation.

The parties also disagree on the structure. RTI argues that even if Section 112(f) applies “a person having ordinary skill in the art understands that comparing logic provides sufficient structure for comparing the cost rate of each path.”149 Broadvox contends that the specification fails *330to describe a corresponding function, rendering the claim indefinite.150

Here, based on the specification and prosecution history, I find that the structure is enclosed in the microprocessing unit (“MPU”) 50, which includes a conventional address 60, control 62, and data buses 64, and an input output bus 66.151 I thus construe the function as “comparing the cost rate of each path so as to determine a least cost route.” The corresponding structure is enclosed in the MPU 50 and described in column 2 lines 10-11, column 4 lines 1-16, column 6 lines 22-25, and Figures 2 and 5.152

9. “means operatively connected to said switch means and said second jack means for generating a number sequence corresponding to a desired carrier so that said call is routed through said second jack means to the selected communication path and carrier to establish a switched connection between said first telephone and said second telephone”

The word “means” gives rise to a presumption that Section 112(f) applies. RTI once again attempts to rebut the presumption by replacing “means” with “logic” and arguing that an artisan would be able to identify structure.153 However, Federal Circuit law is clear that “[a] pat-entee cannot avoid providing specificity as to structure simply because someone of ordinary skill in the art would be able to devise a means to perform the claimed function.”154

Given that means-plus-function applies, the parties disagree on the proposed structure. Citing to the specification and prosecution history, Broadvox argues that the structure is “the combination of a tone generator with a crystal oscillator (which generates the number sequence), and an analog switch (so that “call is routed through said second jack means to the selected communication path ... ”).155 Broadvox cites column 2 lines 11-18, column 4 lines 34-39, and Figure 2 for support.156

RTI contends that Broadvox’s proposed construction “violates the doctrine of claim differentiation” by limiting claim 1 to the structure of dependent claim 5.157 Claim 5 states “the device according to claim 1 wherein said means for generating said number sequence comprises a dual tone multifrequency generator.”158 RTI also objects that Broadvox improperly imports terms from the “preferred embodiment” by citing to column 4 lines 34-39 and Figure 2.159

RTFs objections are meritless. Where a claim term and a dependent claim term “concern the same function” and a structure for performing that function is disclosed, “a patentee cannot rely on claim differentiation to broaden a means-plus-function limitation beyond those structures *331specifically disclosed in the specification.” 160 Additionally, Section 112(f) requires a court to import “the corresponding structure, material, or acts described in the specification.” 161

I therefore construe the claimed functions as “generating a number sequence corresponding to a desired carrier for routing call to establish a switched connection between said first telephone and said second telephone.” I construe the corresponding structure as described in column 2 lines 11-18, column 4 lines 34-39, and Figure 2.

C. Disputed Constructions for Claim 1 of the '769 Patent

1. “at a predetermined time and date”

RTI argues that an artisan would construe the phrase as “at a predetermined date and time.”162 Broadvox responds that this Court should follow Judge Young’s construction in MediaCom I.163 Judge Young defined the phrase as “a time and date for calling the rate provider are selected a substantial period in advance of the call.”164 Moreover, during the '769 Patent reexamination, RTI limited the meaning of “predetermined date and time to overcome prior art,” stating:

It is also noted that [the prior art] fails to meet the claim language because it does not teach that the call rating device connects to the rate provider “at a predetermined time and date.” [The prior art] teaches ... only that the internal clock triggers the processor “at given time intervals.” Programming the system to update at selected time intervals (e.g. once a week) is not the same as programming it to update at a particular date and time (e.g. May 4, 2001 at 8:45 a.m.).165

As Judge Young stated, “[t]he words [at a predetermined date and time] used in the claim are simple English.... On its face, the language signifies that a particular time and date must be selected substantially in advance of the connection.”166 In light of the prosecution history and construction, I mostly agree with Judge Young’s construction. However, I disagree that “at a predetermined date and time” by its plain terms requires that the date and time be selected substantially in advance.167 Nothing in the prosecution history or specification suggests that the word “substantially” is required.168 I therefore construe “at a predetermined date and time” as “a time and date for calling the rate provider selected a period in advance of the call.”

2. “call rating device”

Although the patent does not use the word “means,” Broadvox argues that Section 112(f) applies because the Federal Circuit has recognized that “generic terms ‘mechanism,’ ‘means,’ ‘element,’ and ‘device,’ typically do not connote sufficiently *332definite structure.”169 Broadvox proposes that the phrase be construed as “an identifiable physical component having the function of receiving rate information from a rate provider over a data transfer line, incorporating the rate information and thereafter managing calls over the least cost routing route.”170 For structure, Broadvox pieces together various lines from the specification.171

The phrase at issue is not a means-plus-function limitation under Section 112(f). First, the phrase does not contain the word “means.” The Federal Circuit will not apply Section 112(f) if the limitation contains a term that “is used in common parlance or by persons of skill in the pertinent art to designate structure.”172 “Call rating device” presumptively connotes a sufficient structure to those skilled in the art.173 Walton explains that such devices were known.174 Furthermore, the specification explains that the invention in the earlier filed '085 Patent is a call rating device, also known as a least cost routing device.175 As Broadvox notes, during the '085 Patent reexamination, RTI distinguished its invention from prior art that included “more primitive” least cost routing devices.176 Finally, although he did not construe the phrase, Judge Young noted that “call rating device” is a known generic term for “Least Cost Routing Device.”177 Thus, the specification and common parlance impart sufficient structure such that Section 112(f) does not apply. At the Markman hearing, Broadvox argued that “call rating device” is a vague term because it is not clear what is being rated, but RTI clarified that the rating is “based on cost.”178 For clarity, I construe “call rating device” as used in the patents-at-issue as “least cost routing device.”

3. “transmitting over the data transfer line”

Broadvox urges that the term be construed as “conveying information over the same wire operatively connected to a call rating device on one end and a phone network on the other.”179 RTI urges the Court to construe the phrase as “transmitting over the data transfer line.”180 RTI argues that Broadvox improperly limits the term to mean a single data transfer line even in the face of Federal Circuit law that definite articles such as “a,” “an,” or “the” mean “one or more.”181 Broadvox responds that RTFs proposed construction will mislead the jury into thinking that information is communicated via a data transfer line different from the earlier defined line.182 Thus, the debate is whether “data transfer line” refers to the same *333“data transfer line” mentioned earlier in Claim 1.

Claim 1 states the following limitations:

[i] connecting at a predetermined time and date via a data transfer line the call rating device to a rate provider having billing rate parameters for a plurality of calling stations;

[ii] transmitting over the data transfer line indicia identifying the call rating device and the date and time of the last update of the billing rate parameters ... 183

Although RTI is correct that the antecedent phrase, “a data transfer line” is broad enough to cover multiple lines, each use of the phrase “the data transfer line” still refers to the antecedent phrase.184 The phrase “data transfer line” connects the call rating device to a rate provider. I therefore adopt Broadvox’s construction with the modification that more than one wire may connect the call rating device to the phone network.185 I construe the phrase as “transmitting information over the same wire or wires operatively connected to a call rating device on one end and a phone network on the other.”

4. “verifying if billing rate parameters should be updated”

Broadvox urges the Court to construe the claim as “the rate provider, based on the information received from the call rating device, verifies if the billing rate parameters should be updated.”186 RTI contends that the term should be construed as is: “verifying if billing rate parameters should be updated.”187 The issue is whether the Court must identify the actor doing the “verifying.”

RTI suggests that the Court follow Judge Young’s analysis of a similar term.188 In construing “connecting at a predetermined data and time” in Media-Corn I, Judge Young concluded that “[t]he language does not require that the person responsible for the selection be identified in order to give meaning to the claim.”189 RTI argues that the same is true for the “verifying” step.190

I disagree. As I stated at the Mark-man hearing, “verifying” is an act that requires an actor, while “connecting” may not be.191 If the actor cannot be identified, the claim fails for indefiniteness.192 However, when read in the context of claim 1, there is no doubt that the rate provider does the “verifying.” Claim 1 recites:

*334A method for updating a database ... comprising the steps of:

[i] connecting at a predetermined time and date via a data transfer line the call rating device to a rate provider having billing rate parameters for a plurality of calling stations;

[ii] transmitting over the data transfer line indicia identifying the call rating device and the date and time of the last update of the billing rate parameters;

[iii] verifying if billing parameters should be updated; and

[iv] transmitting from the rate provider to the call rating device the updated billing rate parameters w hen the rate provider determines that an update is required.193

Thus, the call rating device sends information — including information on the last update — to the rate provider. The rate provider verifies if billing parameters should be updated. If the rate provider determines that an update is required, it transmits updated billing rate parameters to the call rating device. I therefore adopt Bro-advox’s construction. I construe “verifying if billing parameters should be updated” as “the rate provider, based on the information received from the call rating device, verifies if the billing rate parameters should be updated.”

5. “transmitting from the rate provider to the call rating device”

Similarly, Broadvox suggests that the term be construed as “the rate provider, based on the information received from the call rating device, transmits the billing rate parameters to the call rating device.” 194 RTI contends that the term be construed as is: “transmitting from the rate provider to the call rating device.”195 The parties disagree on whether to include the phrase “based on the information received from the call rating device.”

Broadvox argues that the phrase derives from the second limitation of claim 1: “transmitting ... indicia identifying the call rating device and the date and time of the last update of the billing rate parameters.” 196 If the rate provider “determines that an update is required” based on this indicia, it transmits the updated billing parameters to the call rating device. Bro-advox also cites to column 5 lines 55-59 of the specification, stating:

As shown in Fig. 7, the rate provider receives the update request from the call rating device (block 160). It receives 1) the calling station’s phone number; 2) the date and time of the last update; and 3) the current date and time (block 162) ... If a newer rate table is available, (block 173), then an update flag is initiated by the processing unit of the rate provider (block 174) and the update is sent ... 197

RTI responds that Broadvox’s added language “breeds confusion and redundancy,” 198 but, based on the claim language and the specification, I disagree. I construe “transmitting from the rate provider to the call rating device” as “the rate provider, based on the information received from the call rating device, transmits the billing rate parameters to the call rating device.”

*335[[Image here]]

*336[[Image here]]

SO ORDERED.