VTN FLOWFILTER with type "out" makes the command hang without any resp code

Created VTN, VBR, FLOWLIST and FLOWLIST ENTRY, VTN FLOWFILTER with direction "out"
the command hangs awithout any response code returmed.

The following is the command tried,
[root@u12 ~]# curl -v --user admin:adminpass -X POST -H 'content-type: application/json' -H 'ipaddr:127.0.0.1' -d '{"flowfilter" : {"ff_type": "out"}}' http://127.0.0.1:8083/vtn-webapi/vtns/vtn_one/flowfilters.json

• About to connect() to 127.0.0.1 port 8083 (#0)
• Trying 127.0.0.1... connected
• Connected to 127.0.0.1 (127.0.0.1) port 8083 (#0)
• Server auth using Basic with user 'admin'
  > POST /vtn-webapi/vtns/vtn_one/flowfilters.json HTTP/1.1
  > Authorization: Basic YWRtaW46YWRtaW5wYXNz
  > User-Agent: curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.13.6.0 zlib/1.2.3 libidn/1.18 libssh2/1.4.2
  > Host: 127.0.0.1:8083
  > Accept: /
  > content-type: application/json
  > ipaddr:127.0.0.1
  > Content-Length: 35
  >

________ IT hangs __________________