Cisco Technology, Inc.

Andrew S Foltan

Raymond G Bahr

Flemming Andreasen

Alex Urquizo

A mechanism provides for communication of 'keep-alive' messages from clients to servers in a packet telephony network environment. The servers may be call agents and the clients may be gateways or MGCP-controlled IP phones. A client (e.g., gateway) registers a virtual endpoint. Upon a period of inactivity in which the client does not receive any commands or acknowledgments from an assigned server (e.g., call agent), the client starts to send keep-alive messages periodically to the server. The keep-alive message may include an endpoint identifier that identifies the registered virtual endpoint. If the server fails to respond to the keep-alive messages after a period of time, the client initiates a fallback mechanism from a first call control protocol (e.g., MGCP) to a second call control protocol (e.g., H.323 or SIP), to provide call control handling using a default application. The keep-alive messages may be sent to other servers among the plural servers that are configured to operate with the client before determining whether to initiate the fallback mechanism. During the fallback state, the keep-alive message may be sent periodically until a response is received from the server. Communications with the assigned server may be reestablished thereupon based on the first call control protocol.

MGCP fallback mechanism enhancement

A method and apparatus provide a data communication device that can process a number of streams of data according to a plurality of services. A host device such as a network access server which may include a router and a number of carrier cards hosts a number of modules. The host and modules are equipped with a messaging application programming interface (API). The API allows the host to discover what services are offered by the modules, and allows the host and modules to form an optimal interface configuration that most effectively handles data connections of different service types, such as voice, data, facsimile, video and so forth. In operation, each module is presented with a stream of data containing multiplexed calls. Each call contains data that is best operated on by one of the particular services. The messaging API allows the host to setup and control the module and sessions of the services offered by the modules depending upon the data types of the connections. Since the modules each offer a variety of services, a stream containing data one or more connections such as voice data, video data, modem data, facsimile data and so forth can be processed by a single module under control of the host.

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Nashua, NH, United States of America

Andrew S Foltan