Command line:

ffmpeg -i default.sdp -an -vcodec copy http://127.0.0.1:8090/feed1.ffm

Output:

ffmpeg version N-33294-g884efd4 Copyright (c) 2000-2012 the FFmpeg developers
  built on Apr 16 2012 10:28:44 with gcc 4.5.2
  configuration: --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-nonfree --enable-version3 --enable-x11grab
  libavutil      51. 46.100 / 51. 46.100
  libavcodec     54. 14.101 / 54. 14.101
  libavformat    54.  3.100 / 54.  3.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 70.100 /  2. 70.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 11.100 /  0. 11.100
  libpostproc    52.  0.100 / 52.  0.100
Input #0, sdp, from 'default.sdp':
  Metadata:
    title           : No Name
  Duration: N/A, start: 0.013633, bitrate: N/A
    Stream #0:0: Video: h264 (High), yuv420p, 352x240 [SAR 200:219 DAR 880:657], 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
Output #0, ffm, to 'http://127.0.0.1:8090/feed1.ffm':
  Metadata:
    title           : No Name
    encoder         : Lavf54.3.100
    Stream #0:0: Video: h264, yuv420p, 352x240 [SAR 200:219 DAR 880:657], q=2-31, 29.97 fps, 1000k tbn, 29.97 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
DTS 0, next:66734 st:0 invalid dropping
[ffm @ 0x1c9d900] pts (66733) < dts (66734) in stream 0
av_interleaved_write_frame(): Invalid argument

Contents of default.sdp:

v=0
o=- 0 0 IN IP4 127.0.0.1
s=No Name
c=IN IP4 192.168.200.165
t=0 0
a=tool:libavformat 53.4.0
m=video 9008 RTP/AVP 96
b=AS:200
a=rtpmap:96 H264/90000
a=fmtp:96 packetization-mode=1; sprop-parameter-sets=Z2QADKzZQWH7/wDIANsQAAADABAAAAMBQPFCmWA=,aOvjyyLA