According to one aspect, a system and method of exchanging GRUUs (Globally Routed User Agent URI (Uniform Resource Identifier)) between a first telephony-enabled device and a second telephony enabled device using a circuit-switched message is provided. Once exchanged, the telephony enabled devices can exchange SIP (session initiated protocol) communications routed by the GRUUs. Any one of the telephony-enabled devices can add a media component to the SIP communications. According to another aspect, a system and method of generating GRUUs is provided. According to another aspect, a system and method of handing off communications to a packet switched network from a circuit switched network is provided.

According to one aspect, a system and method of exchanging GRUUs (Globally Routed User Agent URI (Uniform Resource Identifier)) between a first telephony-enabled device and a second telephony enabled device using a circuit-switched message is provided. Once exchanged, the telephony enabled devices can exchange SIP (session initiated protocol) communications routed by the GRUUs. Any one of the telephony-enabled devices can add a media component to the SIP communications. According to another aspect, a system and method of generating GRUUs is provided. According to another aspect, a system and method of handing off communications to a packet switched network from a circuit switched network is provided.

According to one aspect, a system and method of exchanging GRUUs (Globally Routed User Agent URI (Uniform Resource Identifier)) between a first telephony-enabled device and a second telephony enabled device using a circuit-switched message is provided. Once exchanged, the telephony enabled devices can exchange SIP (session initiated protocol) communications routed by the GRUUs. Any one of the telephony-enabled devices can add a media component to the SIP communications. According to another aspect, a system and method of generating GRUUs is provided. According to another aspect, a system and method of handing off communications to a packet switched network from a circuit switched network is provided.

Methods and apparatus for initiating a PTT call from a caller client device to a recipient client device. The methods and apparatus register the caller client device with the PTT system, wherein caller data identifying the caller client device is transmitted to the PTT system; store the caller data; generate, at the caller client device, a channel request message that includes channel allocation data and call invite messaging information; transmit the channel request message to the PTT system; parse the call invite messaging information from the channel request message; generate a call invite message based upon the call invite messaging information and the stored caller data; and establish the PTT call between the caller client device and the recipient client device based upon the call invite message. Additionally, the call invite messaging information includes an identification number and not the URI of the recipient client device.

According to one aspect, a system and method of exchanging GRUUs (Globally Routed User Agent URI (Uniform Resource Identifier)) between a first telephony-enabled device and a second telephony enabled device using a circuit-switched message is provided. Once exchanged, the telephony enabled devices can exchange SIP (session initiated protocol) communications routed by the GRUUs. Any one of the telephony-enabled devices can add a media component to the SIP communications. According to another aspect, a system and method of generating GRUUs is provided. According to another aspect, a system and method of handing off communications to a packet switched network, from a circuit switched network is provided.

A method for creating a virtual SIP user agent by use of a webRTC enabled web browser comprises a user logging in to a web application server via a webRTC enabled web browser. The web application server uses the logged on user identity to lookup an associated SIP user identity along with a registrar server address and the web application server initiates a SIP registration procedure using its IP address as the registered contact.

A method for creating a virtual SIP user agent by use of a webRTC enabled web browser comprises a user logging in to a web application server via a webRTC enabled web browser. The web application server uses the logged on user identity to lookup an associated SIP user identity along with a registrar server address and the web application server initiates a SIP registration procedure using its IP address as the registered contact.

Systems, methods, and computer program products for determining network characteristics are provided. The network characteristics may be used to facilitate changes to how content is delivered over a network, such as to avoid network congestion, to provide improved throughput, or to provide a good (or better) user experience, such as when streaming media. For example, the network characteristics may be determined, in part, by tracking domain name resolution requests by using specially formulated domain names that require resolution at an authoritative name server.

According to one aspect, a system and method of exchanging GRUUs (Globally Routed User Agent URI (Uniform Resource Identifier)) between a first telephony-enabled device and a second telephony enabled device using a circuit-switched message is provided. Once exchanged, the telephony enabled devices can exchange SIP (session initiated protocol) communications routed by the GRUUs. Any one of the telephony-enabled devices can add a media component to the SIP communications. According to another aspect, a system and method of generating GRUUs is provided. According to another aspect, a system and method of handing off communications to a packet switched network, from a circuit switched network is provided.

According to one aspect, a system and method of exchanging GRUUs (Globally Routed User Agent URI (Uniform Resource Identifier)) between a first telephony-enabled device and a second telephony enabled device using a circuit-switched message is provided. Once exchanged, the telephony enabled devices can exchange SIP (session initiated protocol) communications routed by the GRUUs. Any one of the telephony-enabled devices can add a media component to the SIP communications. According to another aspect, a system and method of generating GRUUs is provided. According to another aspect, a system and method of handing off communications to a packet switched network from a circuit switched network is provided.