# File sipper/sdp/sdp_generator.rb, line 98
    def self.make_sdp(session_hash, ip, port, codecs, type)
      sdp = make_no_media_sdp(session_hash, ip)
      h = {}
      ma = []
      if codecs.include?('G711U')
        h[:m] =   sprintf("audio %s RTP/AVP 0", port.to_s.chomp)
        ma << 'rtpmap:0 PCMU/8000'        
      end
      if codecs.include?('G711A')
        if h[:m]
          h[:m] << " 8"
        else  
          h[:m] =   sprintf("audio %s RTP/AVP 8", port.to_s.chomp)
        end
        ma << 'rtpmap:8 PCMA/8000'
      end
      if codecs.include?('DTMF')
        if h[:m]
          h[:m] << " 101"
        else  
          h[:m] = sprintf("audio %s RTP/AVP 101", port.to_s.chomp)
        end
        ma << 'rtpmap:101 telephone-event/8000'
      end
      sdp.add_media_lines(h)
      sdp.add_media_attribute_at(0, type.downcase) if type
      ma.each do |a|
        sdp.add_media_attribute_at(0, a)    
      end
      sdp
    end