Large frame path mtu discovery and communication for fcoe devices

Abstract

Embodiments of the invention relate to performing network communications according to an existing protocol by using frames that are larger than those usually allowed by the existing protocol. Thus, embodiments of the present invention provide for an extension of the existing protocol which allows for the use of larger frames. Embodiments provide for use of various negotiation and initialization mechanisms of the existing protocol with additional modifications to allow for the negotiation of the use of larger frames. Some embodiments ensure that the negotiations are performed in such a manner that devices that feature the improvements of the present invention can communicate with devices that do not feature these improvements.

What is claimed is: 
     
         1 . A system comprising:
 a network comprising a fabric;   a first device connected to the network; and   a second device connected to the network,   wherein the first device, the second device and the fabric are configured to negotiate a frame size larger than allowed by standards, and the first and second devices are configured to communicate through the network using frames of the negotiated frame size.   
     
     
         2 . The system of  claim 1 , wherein negotiating a frame size larger than allowed by standards is defined by negotiating a payload size larger than allowed by standards. 
     
     
         3 . The system of  claim 1 , further including a legacy device, wherein the legacy device is incapable of handling frames of size larger than allowed by standards, the first device, the legacy device and the fabric being configured to negotiate a frame size in accordance with standards for communications between the first device and the legacy device. 
     
     
         4 . The system of  claim 1 , wherein the first device, the second device and the fabric are configured to negotiate a frame size larger than allowed by standards while they perform connection initialization operations specified by standards. 
     
     
         5 . The system of  claim 4 , wherein the connection initialization operations specified by standards include FIP advertisement, FIP solicitation, fabric login (FLOGI) and port login (PLOGI) operations. 
     
     
         6 . A method for operating a networked system including at least a first and second device connected to a network including a fabric, the method comprising:
 negotiating a frame size between the first device, the second device and the fabric, the negotiated frame size being larger than allowed by standards; and   communicating between the first and second devices through the network using frames of the negotiated frame size.   
     
     
         7 . The method of  claim 6 , wherein negotiating a frame size larger than allowed by standards is defined by negotiating a payload size larger than allowed by standards. 
     
     
         8 . The method of  claim 6 , wherein the network further includes a legacy device incapable of handling frames of size larger than allowed by standards, the method further including
 negotiating a second frame size for communication between the first device and the legacy device by the first device, the second device and the fabric, the second frame size being in accordance with standards;   communicating between the first and legacy devices through the network using the second frame size.   
     
     
         9 . The method of  claim 6  further including performing connection initialization operations specified by standards by the first device, the second device and the fabric, said connection initialization operations taking place while the first device, the second device, and the fabric are negotiating a frame size larger than allowed by standards. 
     
     
         10 . The method of  claim 9 , wherein the connection initialization operations specified by standards include FIP advertisement, FIP solicitation, fabric login (FLOGI) and port login (PLOGI) operations. 
     
     
         11 . The method of  claim 10 , wherein the performance of connection initialization operations specified by standards and the negotiation of the frame size larger than allowed by standards include sending one or more initialization frames specified by the standards as being part of the connection initialization operations, said frames including an additional field that is not specified by standards, said additional field at least partially defining a suggested frame size that is larger than allowed by standards. 
     
     
         12 . The method of  claim 11 , wherein the one or more initialization frames include at least one of the group consisting of: an FIP frame, a frame including a PLOGI request and a frame including a PLOGI response. 
     
     
         13 . The method of  claim 11 , wherein the suggested frame size that is larger than allowed by standards is defined by defining a suggested payload size larger than allowed by standards. 
     
     
         14 . The method of  claim 13 , wherein the suggested payload size that is larger than allowed by standards is defined by the use of the additional field in conjunction with a conventional field that is part of the frame, the conventional field storing a payload size that is allowed by standards. 
     
     
         15 . The method of  claim 14 , wherein the suggested payload size that is larger than allowed by standards is defined in terms of a predefined mathematical formula based on the values held in the additional field and the conventional field. 
     
     
         16 . The method of  claim 15 , wherein the additional field is associated with a default value, the default value being a value usually placed in that field by conventional devices, the predefined mathematical formula being such that if the default value is stored in the additional field, the predefined formula results in a payload size that is equal to the payload size stored by the conventional field. 
     
     
         17 . A method performed by a device connected to a network including a fabric the method comprising:
 negotiating a frame size with a second device and the fabric, the negotiated frame size being larger than allowed by standards; and   communicating with the second device through the network using frames of the negotiated frame size.   
     
     
         18 . The method of  claim 17 , wherein negotiating a frame size larger than allowed by standards is defined by negotiating a payload size larger than allowed by standards. 
     
     
         19 . The method of  claim 17 , wherein the network further includes a legacy device incapable of handling frames of size larger than allowed by standards, the method further including
 negotiating a second frame size with the legacy device and the fabric for communication with the legacy device, the second frame size being in accordance with standards;   communicating with the legacy devices through the network using the second frame size.   
     
     
         20 . The method of  claim 17  further including performing connection initialization operations specified by standards, said connection initialization operations taking place while negotiating a frame size larger than allowed by standards. 
     
     
         21 . The method of  claim 20 , wherein the connection initialization operations specified by standards include FIP advertisement, FIP solicitation, fabric login (FLOGI) and port login (PLOGI) operations. 
     
     
         22 . The method of  claim 21 , wherein the performance of connection initialization operations specified by standards and the negotiation of the frame size larger than allowed by standards include sending one or more initialization frames specified by the standards as being part of the connection initialization operations, said frames including an additional field that is not specified by standards, said additional field at least partially defining a suggested frame size that is larger than allowed by standards. 
     
     
         23 . The method of  claim 22 , wherein the one or more initialization frames include at least one of the group consisting of: an FIP frame, a frame including a PLOGI request and a frame including a PLOGI response. 
     
     
         24 . The method of  claim 22 , wherein the suggested frame size that is larger than allowed by standards is defined by defining a suggested payload size larger than allowed by standards. 
     
     
         25 . The method of  claim 24 , wherein the suggested payload size that is larger than allowed by standards is defined by the use of the additional field in conjunction with a conventional field, the conventional field that is part of the frame, the conventional field storing a payload size that is allowed by standards. 
     
     
         26 . The method of  claim 25 , wherein the suggested payload size that is larger than allowed by standards is defined in terms of a predefined mathematical formula based on the values held in the additional field and the conventional field. 
     
     
         27 . The method of  claim 26 , wherein the additional field is associated with a default value, the default value being a value usually placed in that field by conventional devices, the predefined mathematical formula being such that if the default value is stored in the additional field, the predefined formula results in a payload size that is equal to the payload size stored by the conventional field. 
     
     
         28 . A device connected to a network including a fabric, the device including circuitry configured to:
 negotiate a frame size with a second device and the fabric, the negotiated frame size being larger than allowed by standards; and   communicate with the second device through the network using frames of the negotiated frame size.   
     
     
         29 . The device of  claim 28 , wherein the circuitry includes application specific circuitry configured to perform the negotiating and communicating steps. 
     
     
         30 . The device of  claim 28 , wherein the device includes a generally programmable processor and a memory including a plurality of instructions, the instructions being executable at the processor and configured to cause the processor to perform the negotiating and communicating steps. 
     
     
         31 . A device connected to a network including a fabric and including:
 a processor;   a memory connected to the processor and including a plurality of computer executable instructions that are executable at the processor; and   a networking interface connected to the processor and the network,   wherein the computer executable instructions, when executed at the processor, cause the processor to
 negotiate a frame size with a second device and the fabric, the negotiated frame size being larger than allowed by standards, and 
 communicate with the second device through the network using frames of the negotiated frame size. 
   
     
     
         32 . The device of  claim 31 , wherein the device is a computer. 
     
     
         33 . The device of  claim 31 , wherein the device is a storage device. 
     
     
         34 . The storage device of  claim 33 , wherein the storage device is a RAID array. 
     
     
         35 . A network switch connected to a network and to first and second devices through the network, the network switch being configured to:
 negotiate a frame size with the first and second devices, the negotiated frame size being larger than allowed by standards; and   forward communications between the first and second devices, the communications including frames of the negotiated frame size.   
     
     
         36 . A network switch connected to a network and to a first and second devices through the network, the network switch including:
 a processor;   a memory connected to the processor and including a plurality of computer executable instructions that are executable at the processor; and   a networking interface connected to the processor and the network,   wherein the computer executable instructions, when executed at the processor, cause the processor to
 negotiate a frame size with the first and second devices, the negotiated frame size being larger than allowed by standards; and 
 forward communications between the first and second devices, the communications including frames of the negotiated frame size. 
   
     
     
         37 . A computer readable medium comprising a plurality of instructions, the instructions being configured for execution at a device connected to a network including a fabric, the instructions being further configured to cause the device to perform a method when executed at the device, the method comprising:
 negotiating a frame size with a second device and the fabric, the negotiated frame size being larger than allowed by standards; and   communicating with the second device through the network using frames of the negotiated frame size.   
     
     
         38 . A computer readable medium comprising a plurality of instructions, the instructions being configured for execution at a network switch connected to a network and to a first and second devices through the network, the instructions being further configured to cause the network switch to perform the following as a result of execution of the instructions thereon:
 negotiate a frame size with the first and second devices, the negotiated frame size being larger than allowed by standards; and   forward communications between the first and second devices, the communications including frames of the negotiated frame size.   
     
     
         39 . The system of  claim 1 , wherein the network, the fabric, and the standards are respectively a Fibre Channel over Ethernet (FCoE) network, an FCoE fabric, and FCoE standards. 
     
     
         40 . The system of  claim 1 , wherein the negotiated frame size is larger than allowed by FC-BB-5 or comprises a payload size larger than 2112 bytes. 
     
     
         41 . The method of  claim 6 , wherein the network, the fabric, and the standards are respectively a Fibre Channel over Ethernet (FCoE) network, an FCoE fabric, and FCoE standards. 
     
     
         42 . The method of  claim 6 , wherein the negotiated frame size is larger than allowed by FC-BB-5 or comprises a payload size larger than 2112 bytes. 
     
     
         43 . The method of  claim 17 , wherein the network, the fabric, and the standards are respectively a Fibre Channel over Ethernet (FCoE) network, an FCoE fabric, and FCoE standards. 
     
     
         44 . The method of  claim 17 , wherein the negotiated frame size is larger than allowed by FC-BB-5 or comprises a payload size larger than 2112 bytes. 
     
     
         45 . The device of  claim 28 , wherein the network, the fabric, and the standards are respectively a Fibre Channel over Ethernet (FCoE) network, an FCoE fabric, and FCoE standards. 
     
     
         46 . The device of  claim 28 , wherein the negotiated frame size is larger than allowed by FC-BB-5 or comprises a payload size larger than 2112 bytes. 
     
     
         47 . The device of  claim 31 , wherein the network, the fabric, and the standards are respectively a Fibre Channel over Ethernet (FCoE) network, an FCoE fabric, and FCoE standards. 
     
     
         48 . The device of  claim 31 , wherein the negotiated frame size is larger than allowed by FC-BB-5 or comprises a payload size larger than 2112 bytes. 
     
     
         49 . The network switch of  claim 35 , wherein the network, the fabric, and the standards are respectively a Fibre Channel over Ethernet (FCoE) network, an FCoE fabric, and FCoE standards. 
     
     
         50 . The network switch of  claim 35 , wherein the negotiated frame size is larger than allowed by FC-BB-5 or comprises a payload size larger than 2112 bytes. 
     
     
         51 . The network switch of  claim 36 , wherein the network, the fabric, and the standards are respectively a Fibre Channel over Ethernet (FCoE) network, an FCoE fabric, and FCoE standards. 
     
     
         52 . The network switch of  claim 36 , wherein the negotiated frame size is larger than allowed by FC-BB-5 or comprises a payload size larger than 2112 bytes. 
     
     
         53 . The computer readable medium of  37 , wherein the network, the fabric, and the standards are respectively a Fibre Channel over Ethernet (FCoE) network, an FCoE fabric, and FCoE standards. 
     
     
         54 . The computer readable medium of  37 , wherein the negotiated frame size is larger than allowed by FC-BB-5 or comprises a payload size larger than 2112 bytes. 
     
     
         55 . The computer readable medium of  38 , wherein the network, the fabric, and the standards are respectively a Fibre Channel over Ethernet (FCoE) network, an FCoE fabric, and FCoE standards. 
     
     
         56 . The computer readable medium of  38 , wherein the negotiated frame size is larger than allowed by FC-BB-5 or comprises a payload size larger than 2112 bytes.