diff --git a/lib/grammar.js b/lib/grammar.js
index d8178e8..8b1591b 100644
--- a/lib/grammar.js
+++ b/lib/grammar.js
@@ -472,6 +472,31 @@ var grammar = module.exports = {
       names: ['id', 'mStream'],
       format: 'floorid:%s mstrm:%s'
     },
+    {
+      // RFC 3312 precondition
+      push: 'precondition',
+      reg: /^(curr|des|conf):(qos|\S*)(?: (mandatory|optional|none|failure|unknown))? (e2e|local|remote) (none|sendrecv|send|recv)/,
+      names: ['state', 'type', 'strength', 'status', 'direction'],
+      format: function (o) {
+        var str = '%s:%s ';
+        str += o.strength != null ? '%s ' : '%v';
+        str += o.status != null ? '%s ' : '';
+        str += o.direction != null ? '%s ' : '';
+        return str;
+      },
+    },
+    {
+      // RFC 6787; a=cmid:1
+      name: 'resource',
+      reg: /^resource:([^\s]*)/,
+      format: 'resource:%s',
+    },
+    {
+      // RFC 6787; a=cmid:1
+      name: 'cmid',
+      reg: /^cmid:([^\s]*)/,
+      format: 'cmid:%s'
+    },
     {
       // any a= that we don't understand is kept verbatim on media.invalid
       push: 'invalid',
@@ -491,4 +516,4 @@ Object.keys(grammar).forEach(function (key) {
       obj.format = '%s';
     }
   });
-});
+});
\ No newline at end of file
diff --git a/test/compose.test.js b/test/compose.test.js
index f35ebcf..2d99a19 100644
--- a/test/compose.test.js
+++ b/test/compose.test.js
@@ -48,7 +48,8 @@ var sdps = [
   'mediaclk-rtp.sdp',
   'ts-refclk-media.sdp',
   'ts-refclk-sess.sdp',
-  'rtcp-fb.sdp'
+  'rtcp-fb.sdp',
+  `precondition.sdp`,
 ];
 
 sdps.forEach((name) => {
diff --git a/test/coverage.test.js b/test/coverage.test.js
index 5eb5f63..9ed6363 100644
--- a/test/coverage.test.js
+++ b/test/coverage.test.js
@@ -39,7 +39,8 @@ var sdps = [
   'mediaclk-rtp.sdp',
   'ts-refclk-media.sdp',
   'ts-refclk-sess.sdp',
-  'rtcp-fb.sdp'
+  'rtcp-fb.sdp',
+  `precondition.sdp`,
 ];
 
 sdps.forEach((name) => {
diff --git a/test/mrcp.sdp b/test/mrcp.sdp
new file mode 100644
index 0000000..3c6ccf4
--- /dev/null
+++ b/test/mrcp.sdp
@@ -0,0 +1,21 @@
+v=0
+o=hossein 2890844526 2890844527 IN IP4 192.0.2.12
+s=-
+c=IN IP4 192.0.2.12
+t=0 0
+m=application 9 TCP/MRCPv2 1
+a=setup:active
+a=connection:existing
+a=resource:speechsynth
+a=cmid:1
+m=audio 49170 RTP/AVP 0 96
+a=rtpmap:0 pcmu/8000
+a=rtpmap:96 telephone-event/8000
+a=fmtp:96 0-15
+a=sendrecv
+a=mid:1
+m=application 9 TCP/MRCPv2 1
+a=setup:active
+a=connection:existing
+a=resource:speechrecog
+a=cmid:1
\ No newline at end of file
diff --git a/test/parse.test.js b/test/parse.test.js
index 47e3ee0..5e7c83b 100644
--- a/test/parse.test.js
+++ b/test/parse.test.js
@@ -975,4 +975,30 @@ test('ts-refclk-sess', function *(t) {
   t.ok(sessTsRefClocks && sessTsRefClocks.length == 1, 'got one TS Ref Clock at Session Level');
   t.equal(sessTsRefClocks[0].clksrc, 'ntp', 'NTP Clock Source');
   t.equal(sessTsRefClocks[0].clksrcExt, '/traceable/', 'traceable Clock Source');
+});
+
+test('precondition', function* (t) {
+  var sdp = yield fs.readFile(__dirname + '/precondition.sdp', 'utf8');
+
+  var session = parse(sdp + '');
+  t.ok(session, 'got session info');
+  t.equal(session.media[0].precondition[0].status, 'local', 'precondition parsed');
+
+  var rew = write(session);
+  t.ok(rew.indexOf('a=curr:qos') >= 0, 'got qos precondition');
+  t.ok(rew.indexOf('a=des:qos') > rew.indexOf('a=curr:qos'), 'precondition curr and then des state');
+});
+
+
+test('mrcp', function* (t) {
+  var sdp = yield fs.readFile(__dirname + '/mrcp.sdp', 'utf8');
+
+  var session = parse(sdp + '');
+  t.ok(session, 'got session info');
+  t.equal(session.media[0].resource, 'speechsynth', 'MRCP resource parsed');
+  t.equal(session.media[0].cmid, 1, 'MRCP cmid parsed');
+
+  var rew = write(session);
+  t.ok(rew.indexOf('a=resource:') >= 0, 'got MRCP resource');
+  t.ok(rew.indexOf('a=cmid:') >= 0, 'got MRCP cmid');
 });
\ No newline at end of file
diff --git a/test/precondition.sdp b/test/precondition.sdp
new file mode 100644
index 0000000..264b122
--- /dev/null
+++ b/test/precondition.sdp
@@ -0,0 +1,27 @@
+v=0
+o=KSIC 564321 0 IN IP6 2001:56f:b006:abf7:8d62:bff:7d9c:79f9
+s=SS VoLTE
+i=A VoLTE IMS Session
+c=IN IP6 2001:55f:b006:abf7:8d62:bff:7d9c:79f9
+t=0 0
+m=audio 30000 RTP/AVP 114 116 118 111 110
+b=AS:50
+b=RS:0
+b=RR:2000
+a=rtpmap:114 EVS/16000/1
+a=fmtp:114 br=16.4; br-send=16.4; br-recv=16.4; bw=WB; bw-send=WB; bw-recv=WB; hf-only=0; max-red=220
+a=rtpmap:116 AMR-WB/16000/1
+a=fmtp:116 mode-set=8; mode-change-capability=2; max-red=220
+a=rtpmap:111 telephone-event/16000
+a=fmtp:111 0-15
+a=rtpmap:118 AMR/8000/1
+a=fmtp:118 mode-set=7; mode-change-capability=2; max-red=220
+a=rtpmap:110 telephone-event/8000
+a=fmtp:110 0-15
+a=curr:qos local none
+a=curr:qos remote none
+a=des:qos mandatory local sendrecv
+a=des:qos none remote sendrecv
+a=sendrecv
+a=ptime:20
+a=maxptime:240