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What five facts does SIP Proxy Server support for establishing and terminating multimedia communications? jcelso 05-June-2008 08:24:07 AMComments Proxy Server A proxy server is an intermediate entity that receives SIP requests and forwards them on behalf of the requestor. Proxy servers route requests to the users current location, authenticate and authorize users for services, and implement provider call-routing policies. It also enforces polices for a user and provides name mapping. For each new request, a proxy can function either in stateful or stateless mode. When it functions as a stateless proxy server, it acts as a simple forwarding element. A stateless proxy server discards information about a message after the message is forwarded. A stateful proxy server remembers information (specifically, transaction state) about each incoming request and also about requests it sends as a result of processing the incoming request. It uses this information to influence the processing of future messages associated with that request. SIP proxy servers use presence services to track users and to check the willingness and ability of users to communicate with other users on the network. A presence service is an application of the SIP-specific event notification mechanism (RFC 3265 (Session Initiation Protocol (SIP) - Specific Event Notification)). It enables a user to be located regardless of the physical location. It also accepts presence information from users, stores, and distributes the presence information to other interested users. Posted by sagitraz Identify User location: Locates the User Agent Client. If the Proxy cannot locate or connect to the user, it manages the operations necessary to complete those requirements Determine and Negotiate User Capabilities. Must identify the common capabilities and parameters that will allow to User devices to communicate. Determine priorities for common capabilities. List languages spoken Determine User availability. Determines the willingness of the called party to engage in communications Call Setup. Includes "ringing", establishment of call parameters at both called and calling party Call handling. Includes transfer and termination of calls. Call redirection is described in ITU recommendation H.450.3 Posted by srini_murali |
Posted: 06-June-2008 07:10:19 PM By: srini_murali Identify User location: Locates the User Agent Client. If the Proxy cannot locate or connect to the user, it manages the operations necessary to complete those requirements Determine and Negotiate User Capabilities. Must identify the common capabilities and parameters that will allow to User devices to communicate. Determine priorities for common capabilities. List languages spoken Determine User availability. Determines the willingness of the called party to engage in communications Call Setup. Includes "ringing", establishment of call parameters at both called and calling party Call handling. Includes transfer and termination of calls. Call redirection is described in ITU recommendation H.450.3 | |
Posted: 29-June-2008 05:32:00 AM By: sagitraz Proxy Server A proxy server is an intermediate entity that receives SIP requests and forwards them on behalf of the requestor. Proxy servers route requests to the users current location, authenticate and authorize users for services, and implement provider call-routing policies. It also enforces polices for a user and provides name mapping. For each new request, a proxy can function either in stateful or stateless mode. When it functions as a stateless proxy server, it acts as a simple forwarding element. A stateless proxy server discards information about a message after the message is forwarded. A stateful proxy server remembers information (specifically, transaction state) about each incoming request and also about requests it sends as a result of processing the incoming request. It uses this information to influence the processing of future messages associated with that request. SIP proxy servers use presence services to track users and to check the willingness and ability of users to communicate with other users on the network. A presence service is an application of the SIP-specific event notification mechanism (RFC 3265 (Session Initiation Protocol (SIP) - Specific Event Notification)). It enables a user to be located regardless of the physical location. It also accepts presence information from users, stores, and distributes the presence information to other interested users. |