公开(公告)号：US07301913B2

公开(公告)日：2007-11-27

申请号：US10490439

申请日：2002-10-09

申请人： Angelo Corrao ,  Robert Sugar ,  Markus Isomäki

发明人： Angelo Corrao ,  Robert Sugar ,  Markus Isomäki

IPC分类号： H04L12/50 ,  H04L12/16 ,  H04Q11/00

CPC分类号： H04L65/1006 ,  H04L29/06 ,  H04L29/06027 ,  H04L65/607 ,  H04L65/608 ,  H04L69/24

摘要： This invention relates to a SIP and SDP protocols. The idea of the invention is to modify SDP descriptions included in SIP messages to facilitate transcoding. After receiving an INVITE message from a calling party, the SIP proxy negotiates with a transcoder for getting a list of codecs of the transcoder and their address information. The SIP proxy adds the codec list of the transcoder to the received SDP description in the invite message, and sends this way modified SDP description in an INVITE message to a called party. After receiving the modified SDP, the called party selects codecs or a list of suitable codecs according to preferences in the modified SDP and its own preferences.

摘要翻译： 本发明涉及SIP和SDP协议。 本发明的思想是修改包括在SIP消息中的SDP描述以便于代码转换。 在从主叫方接收到INVITE消息之后，SIP代理与代码转换器协商以获得代码转换器的编解码器列表及其地址信息。 SIP代理将转码器的编解码器列表添加到邀请消息中的接收到的SDP描述中，并将这种方式在INVITE消息中发送到被叫方修改的SDP描述。 被叫方在接收到修改的SDP后，根据修改后的SDP的偏好和自己的喜好，选择编解码器或合适的编解码器列表。