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Method for seamless transition of network based applications across different communication media and docked/undocked environments

IP.com Disclosure Number: IPCOM000004912D
Publication Date: 2001-Jul-11
Document File: 2 page(s) / 45K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that implements seamless transitions for network-based applications across different communication media and docked/undocked environments. Benefits include the elimination of the requirement for applications to be restarted or reinitialized when the underlying media changes and when systems move across subnets.

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This is the abbreviated version, containing approximately 70% of the total text.

Method for seamless transition of network based applications across different communication media and docked/undocked environments

Disclosed is a method that implements seamless transitions for network-based applications across different communication media and docked/undocked environments. Benefits include the elimination of the requirement for applications to be restarted or reinitialized when the underlying media changes and when systems move across subnets.

The number of mobile computers and users has increased significantly in a corporate environment. One of the problems associated with the mobile computers is the need for network applications to be re-initialized when the mobile systems transition from one subnet to another in a docked/undocked environment or change media from wired to wireless LANs.

Most conventional applications use TCP/IP as the underlying protocol for information transfer and exchange. The TCP/IP protocol is a connection-oriented protocol that uses the source and destination IP addresses and port numbers to define a connection. Any change to these parameters breaks an existing connection and requires a new connection establishment. When a user moves from one subnet to another or changes from wired to wireless, the computer accesses a DHCP server for address assignment. The assigned address is usually different from the one previously assigned to the computer. The result is that a new IP address causes the end point of the connection to change and a new connection must be established.

The disclosed method requires another parameter to be added to the definition of a TCP end point, a Globally Unique Identifier (GUID) or Universally Unique Identifier (UUID). As the name suggests, the GUID is unique and does not change. A connection is redefined so that the source port, source IP address, and source GUID (option field) and destination port, destination IP address, and destination GUID (option field) serve as end points. When the GUID is present as a connection end-point parameter, the IP address is ignored for purposes of connection context and the GUID and port number define the end point.

In the following example, the client is the station/node trying to establish a connection; the server is the station/node accepting a connection.

TCP establishes a connection by sending a SYN segment, specifying the standard parameters (port number to connect to, initial sequence number (ISN), SYN flag). In addition, TCPIP sends a GUID that is associated with the node trying to establish this connection using the TCP options fields.

On receiving a SYN request with the GUID option set, the server responds back with its own SYN segment, sets the GUID option, and passes the server's GUID. In addition, the server also creates a connection context that accommodates the GUID option.

On receiving the server SYN request, the client creates a connection contex...