Columbia University

Lucent Technologies Inc.

Alcatel-lucent USA Inc.

Alcaltel Lucent

Kundan Singh

Henning Gunther Schulzrinne

Milind Madhav Buddhikot

Scott Corey Miller

Adiseshu Hari

Gautam Nair

A network telephony system is provided which enables unified messaging services. The system generally includes at least one user agent operatively coupled to a data network and a signalling server operatively coupled to the data network. The user agents are telephony endpoints, such as standalone Internet telephony appliances or personal computers with appropriate telephony software. A messaging server is provided which is operatively coupled to the data network and is responsive to the signaling server. The system also includes a media server which is operatively coupled to the network and includes computer data storage media for storing message files. The media server is responsive to the messaging server and, on occurrence of a message condition, is directly accessible to a calling party to store a message file for subsequent retrieval by a called party.

System and method for unified messaging in inter/intranet telephony

A mobile node includes a processor, a network interface, and a storage device having computer program code for execution by the processor. The computer program code includes a network layer for transmitting and receiving packets and an intermediate driver that transmits packets to the network layer and receives packets from the network layer using a virtual interne protocol (IP) address to identify the mobile node. The intermediate driver transmits packets to the network interface and receives packets from the network interface using a routable actual IP address to identify the mobile node. The intermediate driver permits the actual IP address to change when the mobile node moves from a first subnet to a second subnet without a corresponding change in the virtual IP address. A corresponding NAT associates the virtual IP address with a second actual IP address when the NAT is notified that the mobile node is in the second subnet.

Method and system for mobility across heterogeneous address spaces

A mobile node includes a processor, a network interface, and a storage device having computer program code for execution by the processor. The computer program code includes a network layer for transmitting and receiving packets and an intermediate driver that transmits packets to the network layer and receives packets from the network layer using a virtual internet protocol (IP) address to identify the mobile node. The intermediate driver transmits packets to the network interface and receives packets from the network interface using a routable actual IP address to identify the mobile node. The intermediate driver permits the actual IP address to change when the mobile node moves from a first subnet to a second subnet without a corresponding change in the virtual IP address. A corresponding NAT associates the virtual IP address with a second actual IP address when the NAT is notified that the mobile node is in the second subnet.

A conferencing server is provided for a data network telephony system for facilitating multi-party call conferencing. The conferencing server generally includes a session initiation protocol (SIP) signaling interface and a media conferencing module. The media conferencing module includes a number of selectable media decoders compliant with known media CODEC protocols, such as G.711. A number of media stream queues s are selectively coupled to the media decoders for storing the decoded incoming media streams. A jitter correction processor is provided to compensate for arrival time jitter in the data stored in the media stream queues. A mixer, which receives the jitter corrected data from each of the queues, generates an aggregate conferencing stream of all active participants and generates individual participant conference streams for each active participant in the conference. A number of selectable media encoders are then used to encode the individual participant conference streams in accordance with a media CODEC protocol supported by the respective participant. The encoded participant conference streams are then distributed to the various conference participants via the data network, such as the Internet.

System and method for conferencing in inter/intranet telephony

A network telephony system is provided which enables unified messaging services. The system generally includes at least one user agent () operatively coupled to a data network () and a signalling server operatively coupled to the data network (). The user agents () are telephony endpoints, such as standalone Internet telephony appliances or personal computers with appropriate telephony software. A messaging server () is provided which is operatively coupled to the data network () and is responsive to the signaling server (). The system also includes a media server (A,B) which is operatively coupled to the network and includes computer data storage media for storing message files. The media server is responsive to the messaging server () and, on occurrence of a message condition, is directly accessible to a calling party to store a message file for subsequent retrieval by a called party.

Growing community of inventors

New York, NY, United States of America

Kundan Singh