Method and Apparatus for Detection of Port Name in a Loop Network

Abstract

A method and apparatus for detection of a port name in a loop network is provided, particularly a loop network in the form of a Fibre Channel Arbitrated Loop (FC-AL). The loop network ( 100 ) has a plurality of devices ( 120 ) each device ( 120 ) having at least one port ( 211, 212 ) on the loop network ( 100 ). The method includes determining which ports ( 211, 212 ) are populated with devices ( 120 ) for which the unique port name (WWPN) is not known. The populated ports are then all bypassed and a mode is entered on the loop network ( 100 ) in which idle frames are transmitted around the loop network ( 100 ). One port is un-bypassed at a time and the port name from the un-bypassed port is received and recorded. The port name is received from the un-bypassed port in a Loop Initialisation Select Master (LISM) frame transmitted by the un-bypassed port.

1 . A method for detection of a port name in a loop network, the loop network having a loop, a plurality of devices each device having at least one port on the loop network and each port having a unique hard port name, the method comprising: 
 determining which ports are populated with devices for which the port name is not known;    bypassing all the populated ports;    entering a mode on the loop network in which idle frames are transmitted around the loop network; and    un-bypassing one port at a time and receiving the port name from the un-bypassed port, without affecting any existing port bypasses.    
   
   
       2 . A method as claimed in  claim 1 , wherein the un-bypassed port transmits frames including its port name.  
   
   
       3 . A method as claimed in  claim 1 , wherein the method includes un-bypassing all the populated ports once all the unique port names of the populated ports are known.  
   
   
       4 . A method as claimed in  claim 1 , wherein the loop network includes at least one enclosure containing one or more devices, each enclosure having an enclosure control device with bypass control over the ports in the enclosure.  
   
   
       5 . A method as claimed in  claim 4 , wherein an enclosure is bypassed prior to entering the mode in which idle frames are transmitted around the loop network within the enclosure.  
   
   
       6 . A method as claimed in  claim 4 , wherein each enclosure has a determining device, the determining device sending the idle frames and receiving the port names.  
   
   
       7 . A method as claimed in  claim 1 , wherein the loop network is a Fibre Channel Arbitrated Loop (FC-AL) and the unique port name is the World Wide Port Name.  
   
   
       8 . A method as claimed in  claim 1 , wherein the port name is received from the un-bypassed port in a Loop Initialisation Select Master (LISM) frame transmitted by the un-bypassed port.  
   
   
       9 . A method as claimed in  claim 1 , wherein if no port name is received from a device, the device is non-participating or faulty.  
   
   
       10 . An apparatus for detection of a port name in a loop network, the apparatus comprising: 
 a loop network including at least one loop;    a plurality of devices connected to the loop via ports, each port having a unique hard port name;    means for bypassing ports on the loop;    means for determining which ports are populated on the loop with devices for which the port name is not known;    a determining device capable of entering a mode on the loop network in which idle frames are transmitted around the loop network;    the determining device receiving and recording the port names for each populated port on the loop.    
   
   
       11 . An apparatus as claimed in  claim 10 , wherein the loop network includes at least one enclosure containing one or more devices, each enclosure having an enclosure control device with bypass control over the ports in the enclosure.  
   
   
       12 . An apparatus as claimed in  claim 11 , wherein an enclosure includes means for bypassing the enclosure from the loop network and the determining device entering a mode in the bypassed enclosure in which idle frames are transmitted around the enclosure.  
   
   
       13 . An apparatus as claimed in  claim 11 , wherein the determining device is the enclosure control device.  
   
   
       14 . An apparatus as claimed in  claim 10 , wherein the loop network is a dual loop network in which a device has two ports, one on each loop.  
   
   
       15 . An apparatus as claimed in  claim 10 , wherein the loop network is a Fibre Channel Arbitrated Loop (FC-AL) and the unique port name is the World Wide Port Name.  
   
   
       16 . An apparatus as claimed in  claim 10 , wherein the port name is received from an un-bypassed port in a Loop Initialisation Select Master (LISM) frame transmitted by the un-bypassed port.  
   
   
       17 . A computer program product stored on a computer readable storage medium comprising computer readable program code means for detection of device names in a loop network, the loop network having a loop, a plurality of devices each device having at least one port on the loop network and each port having a unique hard port name, the program code means performing the steps of: 
 determining which ports are populated with devices for which the port name is not known;    bypassing all the populated ports;    entering a mode on the loop network in which idle frames are transmitted around the loop network;    un-bypassing one port at a time and receiving the port name from the un-bypassed port, without affecting any existing port bypasses.