Patent Grant
6968386
1. Technical Field
The present invention relates to file transfer applications between a user workstation and a web server wherein the workstation is connected to the web through a Local Area Network (LAN) or a Wide Area Network (WAN), and relates particularly to a system for transferring data files between a user workstation and a web server.
2. Background
The transfer of data files between a web server and a user workstation is done using applications such as a web browser or a file transfer user software. Such a software involves a transfer protocol such as Hypertext Transfer Protocol (HTTP) used when the web browser transfers data files from remote web servers to graphically display the web contents on the monitor of the workstation.
Although HTTP Is adapted for downloading HTML files and the small bit maps displayed with them, it is not designed for transferring large data files. However, another protocol File Transfer Protocol (FTP) can download large files and resume transfer after interruptions. Insofar as transferring files via e-mail attachments is inefficient or impractical when dealing with large documents, FTP is the only open standard solution for efficiently posting new HTML pages onto a web site or sharing graphics laden files.
Many TCP/IP applications can run over Internet, most of them being user server applications. As each connection request is received, a user workstation process and a server process start. There may be several processes running simultaneously on both user workstation and server. To facilitate this process, each application (FTP for example) is assigned a unique address called a port. The related application is bound to this particular port. There are thousands of ports on a server or a user workstation that can be used. A standard port assignment is defined as a framework. For example FTP uses TCP port 21 and HTTP uses TCP port 80. Other values may be used for these applications when necessary.
Today, growing numbers of power users, telecommuters, and corporate Internet managers are unleashing the protocol's potential by using FTP users (file transfer software applications designed for users) to minimize time spent online. In fact, for anyone that even touches the Internet, “FTP user” should be spoken in the same breath as “e-mail” and “browser” when describing efficient desktop needs.
Web browsing or other internal applications are very often used when download of file is running and has impact on the performance of both the application and the file transfer and introduces delay and sometimes error. The main reason is that some resources are shared as the file transfer uses a lot of the internal hardware and software resources.
Therefore, there is a need to reduce the number of hardware and software resources located in the main processing system involved normally in the file download mechanism in order to improve the performance of both the file transfer and the other tasks running in the station.
Accordingly, the main object of the invention is to provide a system for connecting directly the network of a user workstation to the workstation hard disk and bypassing the main system bus, the main memory and the main processor in order to achieve a faster data file transfer and let other tasks run in the main processor to take advantages of all available resources.
The invention relates therefore to a system for downloading a data file from a web server to a user workstation through a network to which is connected the user workstation, this one including a hard disk for storing the data file being transferred over a SCSI bus. The user workstation includes a dual-port memory for storing temporarily the data file, a network logic unit interconnected between the network and the input port of the dual-port memory for receiving the data file from the network and transmitting it to the dual-port memory, and a SCSI logic unit interconnected between the output port of the dual-port memory and the SCSI bus for transferring the data file from the dual-port memory to the hard disk over the SCSI bus.
The invention relates also to a system for downloading a data file from a web server to a user workstation through a network to which is connected the user workstation, this one including a hard disk for storing the data file being transferred over a SCSI bus.
The user workstation includes a dual-port memory for storing temporarily the data file, a network logic unit interconnected between the network and the input port of the dual-port memory for receiving the data file from the network and transmitting it to the dual-port memory, and a SCSI logic unit interconnected between the output-port of the dual-port memory and the SCSI bus for transferring the data file from the dual-port memory to the hard disk over the SCSI bus.
The above and other objects, features and advantages of the invention will be better understood by reading the following more particular description of the invention in conjunction with the accompanying drawings wherein:
The hardware architecture of a current user workstation is given in
As a minimum the user workstation 10 is made of the processor 206, the main memory 202, the LAN adapter 201 and the SCSI adapter 204, all of them communicating through a common system bus 203. Therefore, the arbiter 207 is required to manage the bus allocation. The hard disk 205 is connected to the SCSI adapter 204 through an external SCSI bus 208. The SCSI adapter and bus may be easily replaced by another bus and drives technology such as IDE.
For a download file transfer the following operations take place:
It should be noted that each data transfer is controlled by the file transfer protocol run by the processor. From a hardware standpoint, the data transfers go through the main memory and the system bus. Therefore, during each data transfer, the processor stops its activity which degrades the performance of the user workstation.
It is assumed that TCP/IP is the standard protocol used in network operations. The type of operation to be performed is located in the so-called ‘Port number’ identifying the file transfer protocol to be used. The port scanning function only selects packets with the port number corresponding to the protocol handled by microcontroller 306. There is only one port assigned to an application at a time so this filtering allows to decide whether this packet is handled by micro-controller 306 and the local IP Stack implemented in the LAN adapter or by processor (206) and the main IP stack controlled by the Operating System. A further test which may be performed to avoid errors or bad frames is to check both Source and Destination IP address fields to verify that the frame belongs to a known flow and of course the sequence number to validate that the frame is the expected frame. These tests can be performed by microcontroller 306. The port scanning function analyses the port number and decides when to perform a file transfer operation. Depending on the port assignment, this file transfer takes place either through the system bus/main memory 203 or locally through the dual-port memory 304. In the latter case, the file transfer operations do not use anymore the main memory and the system bus, which improves the performance of the workstation. This new architecture is therefore open to any type of applications.
In the preferred embodiment, when the user requests the LAN adapter to handle a direct file transfer to memory, it first gives for download the flow identification to process locally. The identification may be the address source and destination and the port number which indicates also which transfer protocol is used. The micro-controller 306 is then able to detect such incoming flow (in case of download) on the LAN controller 302. The data packets are sent to the dual-port memory 304 on one port. The data stored in memory are, thanks to the SCSI controller 303, transferred from the other port of dual-port memory 304 to the hard disk (205) via SCSI BUS 208. The control packets for that flow are managed locally by micro-controller 306.
The upload mechanism is more simple since the user can just give the file location in memory and the destination for the file with a file transfer protocol to use. Micro-controller 306 initializes a file transfer session with the remote location, takes the file from hard disk 205 and puts it in dual-port memory 304 through SCSI BUS 208 and SCSI controller (303). This loading may be done packet by packet depending on the file size. This file splitted into packets is then sent from dual-port memory 304 to the LAN via LAN controller (302). All the data and control processes are managed by micro-controller 306.
It should be noted that the present invention applies to any type of file transfer protocols. As an example, the following protocols can be supported: File Transfer Protocol (FTP), Trivial File Transfer Protocol (TFTP), Network File Server (NFS), Hyper Text Transfer Protocol (HTTP).
The system bus logic is made of an adapter connector 420 which allows the connection of the adapter within the workstation and carries the following hardware signals: data bus, address bus, control signals (read, write, byte enables), bus request, bus grant, interruptions, and a system bus interface VLSI 410 which implements the following functions: bus protocol adaptation, bus timing adaptation, address translation, a transmit FIFO to exchange data from the adapter to the main memory, a receive FIFO to exchange data from the main memory to the adapter and a mailbox to allow the communication between the processor and microcontroller 306.
LAN logic unit 302 of
SCSI logic unit 303 of
Chip select logic decoder 432 decodes the address present onto local bus (401). Therefore, both microcontroller 306 and the processor of the workstation can access the peripheral devices. Four chip select signals are generated: the LAN—controller chip select, the SCSI—controller chip select, the memory—right—port chip select and the memory—left—port chip select.
Address decoder 440 generates the control signals for the buffers, the controllers, the dual-port static memory and the system bus interface. Depending on a slave or master access, the following components are enabled:
It must be noted that the memory map of microcontroller 306 is composed of 9 address ranges relative to the following component wherein each address range is considered as either slave when microcontroller drives the address out local bus 401 or master when the peripheral device (LAN or SCSI controller) drives the bus: the internal ROS as a slave access, the LAN controller as a slave access, the left-port static memory as a slave, the right-port static memory as a slave, the SCSI controller as a slave, the LAN controller as a master to dual-port memory, (this address range is used by the LAN controller to transfer data to/from the left-port static memory), the LAN controller as a master to main memory, (this address range is used by the LAN controller to transfer data to/from the main memory), the SCSI controller as a master (this address range is used by the SCSI controller to transfer data to/from the right-port static memory), and the internal RAM as a slave.
As illustrated in
The microcontroller (306) of the LAN adapter runs the following layers: a communication protocol with the processor 510, a File Transfer Protocol 511, a Port scanning function 512, a LAN controller device driver 513, and a SCSI controller device driver 514. Note that the port scanning function allows to differentiate flows that are handled by the local IP stack (including the file transfer protocol) in microcontroller 306 or flows that are handled by the main IP stack in processor 206. A flow is characterized by at least the source and destination IP address and by the port number.
In reference to
FTP which is used in the preferred embodiment as the file transfer protocol is implemented using the TCP protocol. As shown in
Before any FTP application starts, microcontroller (306) initializes the LAN controller DMA with a master address to main memory. Therefore, the LAN controller communicates directly with the processor through the main memory.
When the user runs the FTP application (WS-FTP for Windows), the session starts with a logon procedure and then graphically represents the user and the server by two opposing tables of directories and files. To apply FTP to a file, the user selects it and clicks the direction that he wants the file to be transferred (server to user in the example).
At this time, microcontroller 306 initializes the LAN controller DMA with a master address to dual-port memory (304). Therefore, the LAN controller 302 will store the incoming network data locally.
Data connections are initialized by the server to a port of a user workstation identified in a port—command. The port scanning routine analyses the port—commands coming-in. When the file transfer port—command is detected, microcontroller 306 runs the file transfer routine between LAN controller 302 and SCSI controller 303. LAN controller 422 stores the burst of data in dual-port memory 304 while SCSI controller 423 reads these data to write them on the hard disk through the SCSI bus. These operations take place until the entire file is received. Then, microcontroller (306) informs the processor which alerts the FTP application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 00480015 | Dec 1999 | EP | regional |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4570217 | Allen et al. | Feb 1986 | A |
| 5795297 | Daigle | Aug 1998 | A |
| 6157955 | Narad et al. | Dec 2000 | A |
| 6526446 | Yang et al. | Feb 2003 | B1 |
