Fairness scheme method and apparatus for pause capable and pause incapable ports

Abstract

A network device, which includes a port, a tag generation unit and a flow control module, is provided. The port, which is connected to a network entity, is configured to send and receive a data packet. The tag generation unit is configured to generate a tag based upon the network entity. The tag generation unit is also configured to add the tag to the data packet and to activate the tag. The flow control module is coupled with a buffer, and is configured to control storage of the data packet into the buffer. The flow control module is also coupled with the port, and is configured to control a communication session conducted between the network device and the network entity based upon the tag.

1 . A network device comprising:
 a port configured to send and receive a data packet, wherein the port is connected to a network entity;   a tag generation unit configured to generate a tag based upon the network entity, said tag generation unit being configured to add the tag to the data packet and to activate the tag; and   a flow control module coupled with the port and configured to control a communication session conducted between the network device and the network entity based upon the tag.   
   
   
       2 . The network device as recited in  claim 1 , wherein said network entity comprises a pause capable device. 
   
   
       3 . The network device as recited in  claim 1 , wherein said network entity comprises a pause incapable device. 
   
   
       4 . The network device as recited in  claim 2 , wherein said tag generation unit is configured to activate the tag to instruct the flow control module to send a pause frame signal to said network entity. 
   
   
       5 . The network device as recited in  claim 2 , wherein said tag generation unit is configured to deactivate the tag to instruct the flow control module to send a pause off frame signal to said network entity. 
   
   
       6 . The network device as recited in  claim 2 , further comprising a buffer including a watermark unit to determine a current buffer capacity of said buffer; and
 wherein said watermark unit is configured to send a pause frame signal to said network entity when said buffer capacity reaches a first level and to send a pause off frame signal to said network entity when said buffer capacity reaches a second level.   
   
   
       7 . The network device as recited in  claim 2 , wherein said tag generation unit is configured to activate the tag to pause the communication session between the network device and the network entity. 
   
   
       8 . The network device as recited in  claim 2 , wherein said tag generation unit is configured to deactivate the tag to initiate the communication session between the network device and the network entity. 
   
   
       9 . The network device as recited in  claim 3 , wherein the tag generation unit is configured to activate the tag to instruct the flow control module to drop said data packet. 
   
   
       10 . The network device as recited in  claim 3 , wherein said tag generation unit is configured to deactivate the tag to instruct the flow control module to add the packet to said buffer. 
   
   
       11 . The network device as recited in  claim 6 , wherein said buffer includes a watermark unit to determine a current buffer capacity of said buffer; and
 wherein said watermark unit is configured to instruct said flow control module to drop said data packet when said buffer capacity reaches a first level and to instruct said flow control module to add the data packet to said buffer when said buffer capacity reaches a second level.   
   
   
       12 . The network device as recited in  claim 3 , wherein said tag generation unit is configured to activate the tag to terminate a packet acceptance communication session between the network device and the network entity. 
   
   
       13 . The network device as recited in  claim 3 , wherein said tag generation unit is configured to deactivate the tag to initiate a packet acceptance communication session between the network device and the network entity. 
   
   
       14 . A network device comprising:
 a first port configured to send and receive a first data packet, wherein the first port is connected to a pause capable device;   a second port configured to send and receive a second data packet, wherein the second port is connected to a pause incapable device;   a tag generation unit configured to generate a first tag for the first data packet and to generate a second tag for the second data packet, said tag generation unit being configured to add the first tag to the first data packet and add the second tag to the second data packet, said tag generation unit being configured to activate the first tag and second tag; and   a flow control module coupled with the first and second port and configured to control a first communication session conducted between the network device and the pause capable device based upon the first tag and to control a second communication session conducted between the network device and the pause incapable device based upon the second tag.   
   
   
       15 . The network device as recited in  claim 14 , wherein said tag generation unit is configured to activate the tag to instruct the flow control module to send a pause frame signal to said pause capable device. 
   
   
       16 . The network device as recited in  claim 14 , wherein said tag generation unit is configured to deactivate the tag to instruct the flow control module to send a pause off frame signal to said pause capable device. 
   
   
       17 . The network device as recited in  claim 14 , further comprising a buffer including a watermark unit to determine a current buffer capacity of said buffer; and
 wherein said watermark unit is configured to send a pause frame signal to said pause capable device when said buffer capacity reaches a first level and to send a pause off frame signal to said pause capable device when said buffer capacity reaches a second level.   
   
   
       18 . The network device as recited in  claim 14 , wherein said tag generation unit is configured to activate the tag to pause the communication session between the network device and the pause capable device. 
   
   
       19 . The network device as recited in  claim 14 , wherein said tag generation unit is configured to deactivate the tag to initiate the communication session between the network device and the pause capable device. 
   
   
       20 . The network device as recited in  claim 14 , wherein the tag generation unit is configured to activate the tag to instruct the flow control module to drop said second data packet received from said pause incapable device. 
   
   
       21 . The network device as recited in  claim 14 , wherein said tag generation unit is configured to deactivate the tag to instruct the flow control module to add said second data packet received from said pause incapable device to said buffer. 
   
   
       22 . The network device as recited in  claim 17 , wherein said buffer includes a watermark unit to determine a current buffer capacity of said buffer; and
 wherein said watermark unit is configured to instruct said flow control module to drop said second data packet received from said pause incapable device when said buffer capacity reaches a first level and to instruct said flow control module to add said second data packet received from said pause incapable device to said buffer when said buffer capacity reaches a second level.   
   
   
       23 . A network device comprising:
 a port for sending and receiving a data packet, wherein the port is connected to a network entity;   a tag generation means for generating a tag based upon the network entity, said tag generation means adding the tag to the data packet activating the tag; and   a flow control means for controlling a communication session conducted between the network device and the network entity based upon the tag.   
   
   
       24 . The network device as recited in  claim 23 , wherein said network entity comprises a pause capable device. 
   
   
       25 . The network device as recited in  claim 23 , wherein the network entity comprises a pause incapable device. 
   
   
       26 . The network device as recited in  claim 25 , wherein said flow control means determines a current buffer capacity of a buffer, said flow control means dropping said packet when said buffer capacity reaches a first level and is configured to store said packet when said buffer capacity reaches a second level. 
   
   
       27 . The network device as recited in  claim 26 , wherein said flow control means determines a current buffer capacity of the buffer, said flow control means sending a pause frame signal to the network entity when said buffer capacity reaches a first level and sending a pause off frame signal when said buffer reaches a second level. 
   
   
       28 . A network device comprising:
 a flow control module configured to negotiate a first communication session between a pause capable device and the network device and a second communication session between a pause incapable device and the network device.   
   
   
       29 . A network device comprising:
 a flow control module configured to unlock a first communication loop developed between a pause capable device and the network device and a second communication loop developed between a pause incapable device and the network device.