Motorola Corporation

Avaya Inc.

Mark Hamlen

Peter M Drozt

Ajaykumar R Idnani

Steven D Upp

Emek Sadot

Rajendra A Panchal

Srinivas Miriyala

An enterprise network includes at least one communication device-, an Open Systems Interconnect (OSI) Layer 2 switch, and a corresponding enterprise switch. The communication device-is connected to at least one of an access point-and a respective port-of the Layer 2 switch. The enterprise network includes a plurality of Emergency Location Information Numbers (ELINs) corresponding to differing segments of the enterprise network. The Layer 2 switchserves at least one of the differing segments. The communication device-includes a discovery agentoperable, when a predetermined first event occurs, to obtain from the Layer 2 switchat least one of an access point identifier, a switch identifier from the Layer 2 switch, and a port identifier identifying the respective port-

Advanced port-based E911 strategy for IP telephony

A method () and apparatus () are arranged and operate for facilitating call routing between sites in an enterprise connected by a private IP network (). A range of identifiers (-) served by IP PBXs (-) in the enterprise may be registered with a SIP registrar () of an inter-site router (). Call requests to a communication unit () outside the home site are routed to the SIP registrar. A site identifier associated with the destination IP PBX allows the call to be completed by the SIP Proxy or the IP PBX where the call was received. When no private IP network is available, a roaming CU registers with a cellular proxy in the visited network. Calls are routed by when an HLR () associated with the CU obtains the roaming number from the cellular proxy () in the visited site. The MSC completes the call to the visited IP PBX using the roaming number and a local SIP registrarforwards the call to the CU.

Inter-site call routing and roaming support

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Palatine, IL, United States of America

Mark Hamlen