Abstract:
A method and apparatus for generating a Fiber Channel compliant frame when a user enters a simple test pattern. A system is provided in which a user can enter an unencoded user test pattern for a Fiber Channel link which is being tested. The system then can then determine and combine additional information that will format the user&#39;s unencoded test pattern into a Fiber Channel compliant frame. The user can then visualize on a display the established Fiber Channel compliant frame and decide whether to modify the Fiber Channel compliant frame before outputting it to the link under test. A comparison can be performed between the data stream that is received after a transmission to the Fiber Channel link to determine whether the Fiber Channel link is in compliance with an established standard.

Description:
BACKGROUND 
     In computer systems, a variety of technologies can be utilized to connect components of a computer system. One such technology is known as Fibre Channel. Fibre Channel employs a network of links established between components. As Fibre Channel links are created, it is necessary to test these links between the various devices on the Fibre Channel system to make sure that the links are compliant with applicable standards. These standards might be industry standards or particular standards established by a customer for the customer&#39;s computer system. 
     In the past, installers of Fibre Channel have been forced to generate a frame of Fibre Channel compliant data by hand. This has involved generating data that meets the specifications of a Fibre Channel data structure. As a result, the testing process has required a great deal of time since the need to generate the test pattern has required much physical labor. Furthermore, it is difficult to know whether a certain pattern of data that is entered by a test technician will result in a data string that taxes the Fibre Channel link to its performance threshold. This is because the encoding of the data pattern and addition of formatting data can alter the characteristics of the data string. Therefore, it is presently a difficult process for a technician to thoroughly test a Fibre Channel link in an efficient manner. In addition, it is very difficult for such a technician to derive a data string that pushes a Fibre Channel link to its ultimate performance threshold. 
     For example, a Fibre Channel compliant frame typically encompasses a serial data string of binary signals, such as voltage signals between 0.6 and 1.6 volts. The transition between the 0.6 and 1.6 volt signals can be a factor for determining whether a Fibre Channel link complies with a compliance standard. Therefore, there is a need for an apparatus and method that allow a user to visualize the transition in a Fibre Channel compliant frame and to determine whether such a transition sequence will be a useful test pattern for the Fibre Channel link. 
     SUMMARY 
     The present invention satisfies the existing needs and provides solutions to existing problems. One advantage of one embodiment of the present invention is that it allows a user to enter a test pattern for a Fibre Channel link and see the resulting Fibre Channel compliant frame that is generated from the test pattern. 
     A further advantage of another embodiment of the invention is that it allows a user to generate a Fibre Channel compliant frame through the use of a computer. 
     Another embodiment of the invention is advantageous in that it permits a user to modify a previously entered test pattern. 
     One embodiment of the invention allows a user to enter an unencoded pattern and format the unencoded pattern into a Fibre Channel compliant frame. The unencoded pattern is converted to a coded pattern and combined with additional data necessary to create the Fibre Channel compliant frame. This is accomplished through the use of a computer. 
     Another embodiment of the invention allows a user to visualize the initial Fibre Channel compliant frame and modify that Fibre Channel compliant frame so as to create a different Fibre Channel compliant frame. This is accomplished in one case by modifying the unencoded pattern input by the user. The resulting Fibre Channel compliant frame is then transmitted through a Fibre Channel link which is under test to see if the Fibre Channel compliant link meets standards established by the user. 
     Other and further advantages and features of the invention will be apparent to those skilled in the art from a consideration of the following description taken in conjunction with the accompanying drawings, wherein certain methods and apparatuses of an installation for practicing the invention are illustrated. However, it is to be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention and scope of the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated into and form a part of the specification, illustrate several embodiments of the present invention and together with the description, serve to explain the principles of the invention. 
     FIG. 1 illustrates a flow chart for allowing a user to enter an unencoded pattern, formatting the unencoded pattern into a Fibre Channel compliant frame, and allowing a user to modify the Fibre Channel compliant frame. 
     FIG. 2 illustrates a sample unencoded user test pattern using symbolic ones and zeroes. 
     FIG. 3 shows a hypothetical encoded user test pattern, e.g., 10 bit format converted from 8 bit format. 
     FIG. 4 illustrates a hypothetical Fibre Channel compliant frame in which the frame comprises header information, encoded pattern, error correction code data, as well as end of frame data. 
     FIG. 5 illustrates a Fibre Channel compliant frame that is transmitted through a Fibre Channel link under test and a possible resulting data stream at the opposite end of the Fibre Channel link. 
     FIG. 6 illustrates a hardware configuration for the testing of a Fibre Channel link. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to FIG. 1, there is shown a system generally designated  100  which comprises a method for performing a preferred embodiment of the present invention. The method includes the actions of entering a pattern that is to be formatted into a Fibre Channel compliant frame  104 , converting the unencoded pattern into a code which satisfies the format for the Fibre Channel compliant frame, combining additional bookkeeping information that permits the Fibre Channel compliant frame to be recognized and processed properly, and allowing the user to visualize and modify the Fibre Channel compliant frame. As shown in FIG. 6, this method is applied to establish a Fibre Channel compliant frame which is then utilized with a Fibre Channel link in order to test whether the Fibre Channel link  650  complies with standards that the user is trying to meet. 
     FIG. 1 demonstrates one embodiment of the present invention. A user is first allowed to enter an unencoded pattern. The pattern is then stored in a memory  604  associated with a computer  600 . Furthermore, the unencoded test pattern  200  entered by a user is encoded by utilizing the computer to encode the unencoded user test pattern so as to generate an encoded test pattern  300 . Typical examples of an unencoded user test pattern  200  and an encoded user test pattern  300  can be seen in FIGS. 2 and 3, respectively. To accomplish the acts of entering an unencoded test pattern and storing that test pattern, means for allowing a user to enter a user test pattern  104  and means for storing the unencoded user test pattern in the memory associated with the computer  108  are utilized. These means are accomplished by simple computer software routines each of which would be readily understood by those of ordinary skill in the art. Furthermore, a means for encoding the unencoded user test pattern so as to generate an encoded user test pattern is utilized to accomplish the act of encoding a user test pattern. For example, a means for performing an 8 bit to 10 bit conversion on the unencoded user test pattern so as to generate a 10 bit formatted test pattern string  112  could be utilized. 
     As the unencoded user test pattern is converted, current and next disparity is determined using a software routine such as means for determining current and next disparity  116  as shown in FIG.  1 . The current disparity at the end of the coding process is also utilized to determine end of frame data  424  shown in FIG.  4 . Similarly, a means for determining error correction code data such as a means for performing a cyclic redundancy check (CRC)  120  is utilized to determine CRC data for the encoded pattern. 
     In a Fibre Channel compliant frame, an established amount of header information will typically be required by the Fibre Channel standard. Therefore, a means for providing header information  124 , such as frame type descriptors and addressing information is utilized to properly format a test pattern into a Fibre Channel compliant frame. In addition to the header information, start-of-frame data, end of frame data, and error correction code data will typically be necessary as well. Furthermore, means for providing idle primitive data can be utilized to provide idle primitive data which act as spacing primitives between frames. The idle primitive data is part of the data string—yet, it is not a part of the Fibre Channel frame. 
     The computer program is programmed with any pre-existing information of which the frame will be comprised. A means for combining the header information with the encoded user test pattern so as to form a data test string  128  is utilized to help establish the Fibre Channel compliant frame. For example, a means for concatenating is utilized to concatenate the start of frame data  412  with header information  404 , which is concatenated with the encoded pattern  416  and error correction code data, such as CRC data  420  and end of frame data  424 , so as to establish a data test string  400  which can be considered a Fibre Channel compliant frame. For example, one typical standard for a Fibre Channel compliant frame utilizes the following specifications: 
     
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 SOF3n Primitives 
                 40 Bits Long 
               
               
                   
                   
               
             
             
               
                   
                 Pattern 
                 240-20480 Bits Long 
               
               
                   
                 CRC for Pattern 
                 40 Bits Long 
               
               
                   
                 EOFn 
                 40 Bits Long 
               
               
                   
                   
               
             
          
         
       
     
     A typical representative example of a Fibre Channel compliant frame can be seen in FIG.  4 . 
     Once the Fibre Channel compliant frame is generated, it is displayed for the user so that the user can determine whether the frame appears useful in testing the Fibre Channel link. A means for displaying the resulting Fibre Channel compliant frame  131 , such as a monitor, can be utilized for this purpose. 
     Once the user has the opportunity to visualize the generated Fibre Channel compliant frame, a means for allowing the user to change the data test string, such as a means  136  for modifying the Fibre Channel compliant frame so as to produce a revised Fibre Channel compliant frame  136 , is utilized. It is envisioned that this would involve a simple software routine that prompts the user whether the user wants to output the frame to the Fibre Channel link-under test  650  or revise the Fibre Channel frame. If the user opts to modify the Fibre Channel compliant frame, one embodiment of the invention allows the user to modify the original unencoded test pattern  200  so as to generate a different unencoded user test pattern. Such a means for allowing the user to change the unencoded test pattern  144  can be seen in FIG.  1 . However, once the user is satisfied with the resulting Fibre Channel compliant frame, the Fibre Channel compliant frame is converted to an output file utilizing a means for outputting the data test string to a Fibre Channel link to be tested  140 . 
     FIG. 6 shows a configuration for one embodiment of the invention. In FIG. 6, a Fibre Channel link  650  is provided for testing. The Fibre Channel link is coupled to the computer  600  through a means for transmitting  668 . The means for transmitting  668  can take the form of any typical coupling device that allows a Fibre Channel link to be connected to the computer  600 . A first end  651  of the Fibre Channel link is coupled to the means for translating while the opposite end  652  of the Fibre Channel link is coupled with a phase locked loop (PLL)  660 , which is typically used in Fibre Channel communications. Furthermore, a means for receiving  664  disposed at the opposite end  652  of the Fibre Channel link is utilized to receive the data stream that is emitted from the opposite end of the Fibre Channel link. 
     A typical Fibre Channel compliant frame  504  and a resulting data stream emitted from the Fibre Channel link  508  is shown in FIG.  5 . This example represents that, due to degradation of the signal through the Fibre Channel link under test, the resulting data stream will vary in certain bit locations. For example, in FIG. 5 a bit that was transmitted as a “0” was received as a “1.” When the data stream is received at the opposite end of the Fibre Channel link, it can be stored for later comparison with the Fibre Channel compliant frame that was initially sent. Through this comparison, a determination can be made as to whether the Fibre Channel link under test is in compliance with standards established by the user or customer. For example, one can determine a bit-error-rate based on the difference between the data stream  508  and the Fibre Channel compliant frame  504 . 
     The means for receiving a data stream  664  could encompass a simple buffer which is capable of receiving and storing the data stream as it is emitted from the Fibre Channel link-under test  650 . Similarly; it could encompass any device that is coupled to the opposite end of the Fibre Channel link and couples the received information to a storage unit. FIG. 6 also shows a data entry device, such as a key pad or keyboard  608  for the entry of the unencoded user test pattern. In addition, a memory  604  of the computer  600  is shown. Furthermore, a monitor  612  can be utilized to display to the user the Fibre Channel compliant frame so that the user can determine whether to modify the Fibre Channel compliant frame. 
     A computer usable medium  616  is shown in FIG.  6 . This computer usable medium is utilized to store as a software program the method demonstrated in FIG.  1 . Each of the actions shown in FIG. 1 can be achieved through simple software routines which cause a computer to perform each given act. Therefore, many of the various actions described above can be accomplished through software code routines which act as means for causing a computer to perform the described activity. Consequently, the computer useful medium can store these software routines as computer readable program code means on its physical storage medium. 
     The apparatuses and methods of the embodiment of the present invention and many of their attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts thereof without departing from the spirit and scope of the invention or sacrificing its material advantages. The form of the invention described above is merely a preferred or exemplary embodiment thereof.