Multiple operating systems sharing a processor and a network interface

1 . A computer system configured for communications, comprising:

a processor;

a first operating system running on the processor;

a second operating system running on the processor; and

a network interface for communicating data,

in which the first and second operating systems are arranged to share usage of the network interface;

characterised in that the network interface operates using a single set of network logical addresses common to both operating systems.

2 . A system according to claim 1 , in which the first operating system is a real time operating system.

3 . A system according to claim 1 , in which the second operating system is a general purpose operating system.

4 . A system according to claim 1 , in which code associated with the first operating system is arranged to receive all incoming packets, and to forward to the second operating system those packets which are not specifically for use by the first operating system or applications running thereon.

5 . A system according to claim 1 , comprising a transmission scheduler which is arranged to selectively forward outgoing data packets from the first and second operating systems for transmission through the network interface.

6 . A system according to claim 5 , in which the transmission scheduler is arranged to give priority to the first operating system.

7 . A system according to claim 5 , in which the transmission scheduler is arranged not to send any packets from the second operating system while there are packets for transmission from the first operating system.

8 . A system according to claim 1 , which is arranged to communicate using Internet protocols.

9 . A system according to claim 1 , in which the first operating system comprises a UDP/IP stack for handling UDP datagrams.

10 . A system according to claim 8 , in which the second operating system comprises a TCP/IP protocol stack.

11 . A system according to claim 1 , in which said first and second operating systems both operate on a single processor.

12 . A system according to claim 11 , comprising an inter-operating system communications channel for carrying messages between said first and second operating systems and/or applications running thereon.

13 . A system according to claim 1 , in which the first operating system has a first subset of address ports and the second operating system has a second subset of address ports, each said subset comprising at least one address port, said first and second subsets being mutually exclusive.

14 . A system according to claim 1 , in which the second operating system provides commands allowing a user to configure the network interface.

15 . A system according to claim 1 , comprising code for providing a real time data transmission channel for communicating data and associated control and/or supervisory signals, in which the code comprises:

first code operating under said first operating system for communicating said data; and

second code operating under said second operating system for communicating said control and/or supervisory signals.

16 . A system according to claim 15 , in which the first operating system is arranged to use a UDP/IP protocol stack to communicate said data.

17 . A voice-over-Internet communications system, comprising a computer concurrently running first and second operating systems, the first operating system being a real time operating system and the second operating system being a general purpose operating system, in which the first operating system is arranged to communicate voice data and the second operating system is arranged to communicate signalling and/or supervisory data, using respective first and second TCP/IP stacks sharing a common IP address.

18 . A method of providing network access to a computer, comprising providing first and second operating systems on the computer, operating concurrently, characterised by sharing a logical network address and allowing said operating systems to share access to a network interface of said computer.

19 . A computer program product comprising code for causing a computer to perform the method of claim 18 .

20 . A computer system configured for communications, comprising:

a processor;

a first operating system running on the processor;

a second operating system running on the processor; and

a network interface for communicating data,

characterised in that the first and second operating systems are arranged to share usage of the network interface.