关于SDP协议的一些经验教训

SDP定义

sdp协议参考 ： RFC4566

SDP Specification

   An SDP session description is denoted by the media type
   "application/sdp" (See Section 8).

   An SDP session description is entirely textual using the ISO 10646
   character set in UTF-8 encoding.  SDP field names and attribute names
   use only the US-ASCII subset of UTF-8