Abstract:
Critical resource management is disclosed. In one embodiment of the invention, a method is provided. First, the method detects whether maximum utilization of a critical resource has been reached. For example, the critical resource can be a number of modems within a modem pool of an Internet Server Provider (ISP). Second, the method determines the priority of access to this critical resource for each of a plurality of clients. For example, such clients can be end-user computers attempting to dial into the modem pool of the ISP. Third, the method denies access to at least one of the clients that have the lowest priority of access to the critical resource. For example, this can mean that a client currently connected to the ISP via a modem of the model pool is disconnected, or can mean that a client attempting to dial into the ISP is refused access.

Description:
This application is a continuation under 35 U.S.C. 1.53(b) of U.S. patent application Ser. No. 09/169,380, filed Oct. 9, 1998, issued as U.S. Pat. No. 6,434,559, which is incorporated herein by reference in its entirety. 

   FIELD OF THE INVENTION 
   This invention relates generally to critical resources, such as but not limited to server connections and modem pools for servers, and more particularly to the management of such critical resources. 
   BACKGROUND OF THE INVENTION 
   Many Internet Service Providers (ISP&#39;s) offer Internet access by what is known as a dial-up line. For example, an ISP may have a given number of modems in a modem pool, such that when a user desires to connect to the Internet, he or she dials the phone number of the ISP, and the modem of the user&#39;s computer connects with one of the modems in the modem pool of the ISP. Many ISP&#39;s offer users the ability to connect for an unlimited or very large number of hours (for example, 150 hours) for a set fee per month. 
   However, the potential exists that the modem pool may become overloaded. For example, an ISP may have sufficient modems in the pool so that only one-third of its subscribers are able to connect at any given time. If more than one-third of the subscribers try to connect, such users may receive a busy signal when attempting to dial into the ISP. This can be frustrating for ISP subscribers, and potentially may result in a loss of business for the ISP, if those subscribers choose to go elsewhere for Internet access, or a need to add additional modems, resulting in increasing costs. 
   For these and other reasons, there is a need for the current invention. 
   SUMMARY OF THE INVENTION 
   The above-mentioned shortcomings, disadvantages and problems are addressed by the present invention, which will be understood by reading and studying the following specification. The invention in one embodiment includes a method. First, the method detects whether maximum utilization of a critical resource has been reached. In one specific embodiment, the critical resource can be a number of modems within a modem pool of an Internet Server Provider (ISP). Second, the method determines the priority of access to this critical resource for each of a plurality of clients. In one specific embodiment, such clients can be end-user computers attempting to dial into the modem pool of the ISP. Third, the method denies or terminates access to at least one of the clients that have the lowest priority of access to the critical resource. In one specific embodiment, this can mean that a client currently connected to the ISP via a modem of the modem pool is disconnected, or can mean that a client attempting to dial into the ISP is refused access. 
   Thus, the invention provides for advantages not found in the prior art. For example, an ISP can structure its service plans such that users who desire guaranteed access to the Internet have higher priority than other users, but pay for such access priority accordingly. The other users may in return pay a lower monthly fee for Internet access, with the understanding that during peak times there is a potential that they will not be able to access the Internet, or may be kicked off the Internet. Thus, the invention provides for better management of critical resources like modem pools than is found in the prior art. 
   The present invention includes systems, methods, servers and computer-readable media of varying scope. In addition to the aspects and advantages of the present invention described in this summary, further aspects and advantages of the invention will become apparent by reference to the drawings and by reading the detailed description that follows. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of a system according to one embodiment of the invention; 
       FIG. 2  is a flowchart of a method according to one embodiment of the invention; and, 
       FIG. 3  is a diagram of a computer in conjunction with which embodiments of the invention may be practiced. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
   Referring first to  FIG. 1 , a block diagram of a system according to one embodiment of the invention is shown. The system includes a critical resource  100 , a server  102 , and a number of clients  104   a  through  104   n . The critical resource  100  provides a manner by which the clients  104   a  through  104   n  are able to connect to the server  102 . For example, in one specific embodiment of the invention, the critical resource may include a number of modems within a modem pool of the server  102  so that a subset of the clients  104   a  through  104   n  are able to connect to the Internet through the server  102 . 
   However, the invention is not particularly limited to a given critical resource  100 . In different specific embodiments of the invention, the critical resource  100  can also be: a number of modems for connection to the server  102 ; a plurality of server connections for the server  102 ; a given amount of bandwidth to the server  102  (for example, in the case of Digital Subscriber Loop (DSL) connections, as known within the art); as well as other critical resources not listed herein. 
   Each of the clients  104   a  through  104   n  can be in one embodiment of the invention an end-user computer having a modem or other manner by which it is able to connect to the server  102  through the critical resource  100 . Thus, such an end-user computer can in one embodiment connect to the Internet via the server  102 . 
   Each client  104   a  through  104   n  has a priority number of predetermined units of access to the critical resource  100  for a given period of units. Such predetermined units in different embodiments can be: units of times (for example, minutes); and, units of information (for example, megabytes of information transferred or received); as well as other predetermined units not listed herein. Such given periods of units in different embodiments can be: a period of time as measured in predetermined units of time (for example, one month as measured in minutes); and, an amount of information as measured in predetermined units of information (for example, one gigabyte of information as measured in kilobytes of information); as well as other given periods not listed herein. 
   The priority number of predetermined units of access for a given client can in one embodiment be determined by a given access plan paid for by the client: a user desiring more guaranteed Internet access, for example, may have 150 priority hours for $20 a month. Another user desiring cheaper but less guaranteed Internet access may have only 5 priority hours but for $5 a month. 
   Each client  104   a  through  104   n  also has an actual number of predetermined units of access to the critical resource  100  for the given period of units. As opposed to the priority number of predetermined units of access for a given client to the critical resource  100 , which in one embodiment can be determined by the user paying a higher fee for a larger priority number, the actual number of predetermined units of access to the critical resource  100  is the actual number of predetermined units that the given client has accessed the critical resource  100  for the given period. 
   For example, in one specific embodiment the given period of units can be one month as measured back from the current date and the predetermined units can be minutes, such that the actual number of predetermined units of access to the critical resource by a given client for the given period of units is the actual number of minutes that the given client accessed the critical resource in the previous month, as measured back from the current date. 
   The server  102  is in one embodiment of the invention a computer as is described later in the detailed description. The server  102  manages access by the clients  104   a  through  104   n  to the critical resource  100 . Upon maximum utilization of the critical resource  100 , the server denies access to at least one of the clients  104   a  through  104   n  that have the lowest priorities of access to the critical resource  100 . 
   In one embodiment, although the invention itself is not so limited, maximum utilization of the critical resource  100  can be defined as each of the modems within a modem pool being used by (that is, connected to) a different of clients  104   a  through  104   n . In such instance, the server  102  then denies access to one of the clients  104   a  through  104   n  connected to the critical resource  100 . For example, the server can in one embodiment disconnect one of the clients  104   a  through  104   n  that has the lowest priority of access. This enables the server  102  to keep at least one modem within the modem pool open for other clients  104   a  through  104   n  to connect to the critical resource  100 . 
   The server  102  determines the priority of access of each of the clients  104   a  through  104   n  to the critical resource  100 , to measure which of the clients have the lowest priority of access, by subtracting the actual number of predetermined units for the given period of units for each client from the priority number of predetermined units for the given period of units for that client. In one embodiment, where the resulting number is greater than or equal to zero, it is set to zero. The resulting number for each client thus is the priority of that client, where a lower number indicates a lower priority. The client or clients with the lowest priority can then be denied access to the critical resource  100  by the server  102 . 
   As an example intended only to illustrate an embodiment of the invention and not intended to limit the invention as a whole, the critical resource  100  may include two modems within a modem pool, and the clients  104   a  through  104   n  may include three clients: a first client having four hours of priority access and having actually accessed the critical resource five hours in the previous month; a second client having one-hundred fifty hours of priority access and having actually accessed the critical resource twenty hours in the previous month; and, a third client having one-hundred fifty hours of priority access and having actually accessed the critical resource two-hundred hours in the previous month. These clients thus have a priority of: 4−5=−1; 150−20=130 (set to 0); and, 150−200=−50, respectively. Therefore, if the first and the second clients were connected, the first client may be denied access because it has lower priority of access; if the first and the third clients were connected, the third client may be similarly denied access; if the second and the third clients were connected, the third client may similarly be denied access. 
   Referring next to  FIG. 2 , a flowchart of a method according to one embodiment of the invention is shown. The method is desirably realized at least in part as one or more programs running on a (server) computer—that is, as a program executed from a computer-readable medium such as a memory by a processor. Such programs are desirably made up of computer instructions for execution on the computer. The programs are also desirably storable on a computer-readable medium such as a floppy disk or a CD-ROM, for distribution and installation and execution on another (suitably equipped) computer. Thus, in one embodiment, a program is executed by a processor of a (server) computer from a medium thereof to deny access to at least one of a plurality of clients having lowest priorities of access to a critical resource upon maximum utilization of the critical resource. 
   In  200 , the method determines maximum utilization of a critical resource. If maximum utilization of the critical resource has been reached, then the method proceeds with  202  and  210 . In  202 , the method determines a priority of access to the critical resource of each of a number of clients, such as in one embodiment the number of clients currently accessing (that is, connected to) the critical resource. The method determines this priority for each of the clients to determine the clients with the lowest priorities. 
   In one embodiment of the invention, the access priority of each client is determined via  204 ,  206  and  208 . In  204 , the actual number of predetermined units of access for a given period of units is determined for each client. In  206 , the priority number of predetermined units of access for the given period of units is determined for each client. Finally, in  208 , the actual number of predetermined units for the given period of units for each client is subtracted from the priority number of predetermined units for the given period of units for that client. The resulting number can in one embodiment be set to zero if it is greater than or equal to zero. The resulting number for each client thus represents the priority of access for that client, where a lower (negative) number indicates a lower access priority. Clients having the same resulting number have equal access. 
   Thus, in  210 , the method denies access to at least one of the clients having the lowest priorities of access to the critical resource. In one embodiment, this is accomplished by disconnecting a currently connected client having the lowest access priority from the critical resource. That is, the method disconnects current access to the at least one of the clients having the lowest priority of access from the critical resource. In another embodiment of the invention, denying access is accomplished by refusing asked-for access by the at least one of the clients having the lowest priority of access to the critical resource. For example, when such a client or clients attempts to connect to the critical resource, such attempted access is refused to the client or clients. 
   Referring finally to  FIG. 3 , a diagram of a computer in conjunction with which embodiments of the invention may be practiced is shown. Computer  310  is operatively coupled to monitor  312 , pointing device  314 , and keyboard  316 . Computer  310  includes a processor (desirably, an INTEL PENTIUM processor), random-access memory (RAM) (desirably, at least thirty-two megabytes), read-only memory (ROM), and one or more storage devices, such as a hard disk drive, a floppy disk drive (into which a floppy disk can be inserted), an optical disk drive, and a tape cartridge drive. The memory, hard drives, floppy disks, etc., are types of computer-readable media. The invention is not particularly limited to any type of computer  310 . Computer  310  desirably is a PC-compatible computer, running a version of the Microsoft Windows operating system. 
   Monitor  312  permits the display of information within a viewing area, including computer, video and other information, for viewing by a user of the computer. The invention is not limited to any particular monitor  312 , and monitor  312  is one type of display device that may be used by the invention. Such monitors include cathode ray tube (CRT) displays, as well as flat panel displays such as liquid crystal displays (LCD&#39;s). Pointing device  314  permits the control of the screen pointer provided by the graphical user interface of operating systems such as versions of Microsoft Windows. The invention is not limited to any particular pointing device  314 . Such pointing devices include mouses, touch pads, trackballs, wheels, remote controls and point sticks. Finally, keyboard  316  permits entry of textual information into computer  310 , as known within the art, and the invention is not limited to any particular type of keyboard. 
   Critical resource management has been described. Although specific embodiments of the invention have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the following claims and equivalents thereof.