'290 claims a method for a user to access an ISP from a remote location.

The claims of the ’290 patent relate to a method of providing network customers with access to a network, such as the internet, when they are away from their normal base of operations. The claimed method operates as follows: a customer who is temporarily in a remote location uses contact and login information (i.e., a telephone number and a preassigned user ID and password) to access the internet through an internet service provider (ISP) or through a third-party modem bank affiliated with that ISP. ’290 patent, col. 4, ll. 62-64 & col. 6, ll. 11-13. Through that internet connection the user then contacts another entity called an “internet service provider access service” or ASP. The ASP provides the user with login information for a new ISP that is more suitable to the customer’s remote location, typically because it is closer to that location. The user then terminates the connection to the internet established through the first ISP and reconnects to the internet by using the new ISP. To generalize the invention, the claims use the term Network Service Provider or NSP to refer to a party in a generic network performing the function of an ISP and providing modem services to network users. ’290 patent, col. 5, ll. 38-44 & col. 6, ll. 11-13. The district court construed all the asserted claims to require the presence of an NSP, a conclusion unchallenged here, and it defined NSP as “a party that provides a connection to the network and authenticates users for access to the network.” The issue on appeal relates to the authentication requirement.

Each of the defendants’ practices are the same in all respects pertinent to this appeal. In each accused architecture, a user dials in to a third-party modem bank associated with the defendant. The modem bank confirms that the user’s ID has a “realm string” indicating that the user has an account with a domain serviced by the modem bank. Thus, for example, if the modem bank services EarthLink customers, the modem bank looks for the term “earthlink” in the customer’s ID, as in the ID “user@earthlink.net.” If the realm string does not match a domain serviced by the modem bank, the modem bank denies the user internet access. If the realm string matches, the modem bank sends the user’s ID and password to the defendant that operates that domain. The defendant checks the ID and password combination against a database of valid users. The result of that authentication query is then communicated to the modem bank, where the user is allowed or denied internet access depending on whether the authentication process indicates that the customer is a valid user entitled to service. Once connected, the defendant updates the user’s access information, which may include new or updated user IDs and passwords, or telephone numbers for third-party modem providers. The user then reconnects at a later time using the new access information.

The problem for MyMail was that the defendants acted as the ASP, and performed authentication, whereas '290 claims that the NSP does the authentication.

The district court found that the patent defines authentication as the process of checking whether the user ID and password are valid. Because the defendants are the ones performing the authentication check and, under MyMail’s theory, the defendants are the ASPs, the district court determined that the alleged NSPs did not perform the required authentication and thus the defendants could not infringe the patent.

The spec provided no succor to MyMail.

The specification also indicates that the ISP (and therefore the NSP) is the entity performing the authentication... The specification shows that the ASP cannot perform the required authentication. Besides explicitly stating that the ISP performs the authentication, the specification describes the authentication and connection steps as being completed before the ASP becomes relevant. See ’290 patent, col. 7, ll. 32-33. With the exception of the unclaimed embodiment discussed below, nothing in the specification suggests that the ASP assists in the connection process... Accordingly, we interpret the specification as requiring the NSP to perform the authentication function.

But the foolishness is that MyMail had already conceded the crucial claim construction point, so had no basis whatsoever to think an appeal would succeed.

Moreover, before the district court MyMail agreed that the patent contemplates that the NSP will perform the authentication function... [C]ounsel acknowledged that under the patent the “NSP has to do [authentication]”.

Having agreed to that construction before the district court, MyMail “cannot now argue against that claim construction simply because it resulted in an adverse ruling on summary judgment.” LizardTech, Inc. v. Earth Res. Mapping, Inc., 424 F.3d 1336, 1341 (Fed. Cir. 2005). In light of the specification’s teachings and MyMail’s admissions [], the district court’s claim construction must be affirmed.

The defendants had cross-appealed patent ownership, an issue subject to state law, not Federal law, as the defendants argued.

MyMail obtained ownership of the ’290 patent through an assignment from Mr. Robert Derby. Mr. Derby had acquired the patent application through a state court foreclosure action on a promissory note secured by the application. The cross-appealing defendants allege that the promissory note was fraudulent and that MyMail’s chain of title is therefore insufficient to establish lawful ownership of the ’290 patent.

A plaintiff must demonstrate legal title to the patent at the inception of the lawsuit to be entitled to sue for patent infringement. Paradise Creations, Inc. v. UV Sales, Inc., 315 F.3d 1304, 1309 (Fed. Cir. 2003). State law—in this case Texas law—governs the question of who has legal title. Int’l Nutrition Co. v. Horphag Research Ltd., 257 F.3d 1324, 1329-30 (Fed. Cir. 2001); Jim Arnold Corp. v. Hydrotech Sys., 109 F.3d 1567, 1572 (Fed. Cir. 1997). Here, MyMail has shown that it was the legal owner of the ’290 patent at the inception of the lawsuit. MyMail relies in part on an enforceable state court judgment that transferred title under Texas law, a judgment that under Texas law is open to challenge only in certain limited circumstances. The cross-appealing defendants must nullify that judgment to establish a break in the title chain. They have not attempted to do so under the applicable provisions of state law.

We agree with the district court that the state court judgment is not amenable to collateral attack in this proceeding and therefore deny relief on the cross-appeal.