Method for exchanging media description information between user agents using session initiation protocol

A method for exchanging media information between user agents using a session initiation protocol (SIP), the method comprising:

• receiving, at a user agent, a session description protocol (SDP) of a session initiation protocol (SIP) message sent by a counter user agent;
• determining a voice data format supportable by the counter user agent from information on an operating system (OS) and a sound module, which is defined by the OS, of the counter user agent included in a media description field in the SDP;
• and
• setting a format commonly supportable by the user agent and the counter user agent as a processing format for voice data of the user agent.

A method for exchanging media information between user agents using a session initiation protocol (SIP), the method comprising:

• generating a first SIP message comprising information on an operating system (OS) and a sound module, which is defined by the OS, of a user agent in a media description field of a session description protocol (SDP), and sending the first SIP message to a counter user agent so as to exchange the information on the OS and the sound module between the user agent and the counter user agent;
• determining whether the media description field is included in an SDP included in a second SIP message received from the counter user agent;
• and
• when the SDP included in the second SIP message comprises the media description field, determining a voice data format supportable by the counter user agent from the information on the OS and the sound module included in a media specification description item in the media description field of the SDP included in the second SIP message, comparing the determined voice data format supportable by the counter user agent with a voice data format supportable by the user agent, and setting a format commonly supportable by the user agent and the counter user agent as a processing format for voice data of the user agent and the counter user agent.

A user agent for exchanging media information with a counter user agent using a session initiation protocol (SIP), said user agent comprising:

• an SIP message generating unit to generate an SIP message comprising, in a media specification description field of a session description protocol (SDP), information on an operating system (OS) and a sound module, which is defined by the OS, used;
• an SIP message originating unit to send the generated SIP message to the counter user agent;
• an SIP message receiving unit to receive an SDP of an SIP message sent by the counter user agent;
• and
• a processing format determining unit to determine a voice data format supportable by the counter user agent from information on an OS and a sound module of the counter user agent included in a media specification description field in the received SDP, and to set a format commonly supportable by both the user agent and the counter user agent as a processing format for voice data of the user agent.

A communication network using a session initiation protocol (SIP) between elements, the network comprising:

• a first user agent;
• and
• a second user agent,
• wherein the first user agent is configured to generate an SIP message comprising, in a media specification description field of a session description protocol (SDP), information on an operating system (OS) and a sound module, which is defined by the OS, of the first user agent, and to send the generated SIP message to the second user agent;
• and
• wherein the second user agent is configured to determine a voice data format supportable by the first user agent from the information on the OS and the sound module of the first user agent included in the SIP message generated and sent by the first user agent, to compare the determined voice data format with a voice data format of the second user agent, and to set a format commonly supportable by both the first user agent and the second user agent as a processing format for voice data of the second user agent.