diff --git a/decoder.go b/decoder.go
index 628c219..9f16686 100644
--- a/decoder.go
+++ b/decoder.go
@@ -540,7 +540,7 @@ func (d *Decoder) decodeBandwidth(m *Message) error {
 		n int
 	)
 	switch bandWidthType := BandwidthType(k); bandWidthType {
-	case BandwidthApplicationSpecific, BandwidthConferenceTotal, BandwidthApplicationSpecificTransportIndependent:
+	case BandwidthApplicationSpecific, BandwidthConferenceTotal, BandwidthApplicationSpecificTransportIndependent, BandwidthSenders, BandwidthReceivers:
 		t = bandWidthType
 	default:
 		msg := fmt.Sprintf("bad bandwidth type %s", k)
diff --git a/fields.go b/fields.go
index 8459f1c..b8f7919 100644
--- a/fields.go
+++ b/fields.go
@@ -391,6 +391,9 @@ const (
 	BandwidthApplicationSpecific BandwidthType = "AS"
 	// defined in RFC 3890
 	BandwidthApplicationSpecificTransportIndependent BandwidthType = "TIAS"
+	// RFC 3556
+	BandwidthSenders   BandwidthType = "RS"
+	BandwidthReceivers BandwidthType = "RR"
 )
 
 // AddBandwidth appends Bandwidth field to Session.
diff --git a/fields_test.go b/fields_test.go
index cbc09b9..5899ebc 100644
--- a/fields_test.go
+++ b/fields_test.go
@@ -94,7 +94,9 @@ func TestSession_AddBandwidth(t *testing.T) {
 	s := new(Session).
 		AddBandwidth(BandwidthConferenceTotal, 154798).
 		AddBandwidth(BandwidthApplicationSpecific, 66781).
-		AddBandwidth(BandwidthApplicationSpecificTransportIndependent, 96000)
+		AddBandwidth(BandwidthApplicationSpecificTransportIndependent, 96000).
+		AddBandwidth(BandwidthSenders, 800).
+		AddBandwidth(BandwidthReceivers, 2400)
 	shouldDecodeExpS(t, s, "bandwidth")
 }
 
diff --git a/testdata/spd_session_ex_bandwidth.txt b/testdata/spd_session_ex_bandwidth.txt
index 96226d9..2ba719a 100644
--- a/testdata/spd_session_ex_bandwidth.txt
+++ b/testdata/spd_session_ex_bandwidth.txt
@@ -1,3 +1,5 @@
 b=CT:154798
 b=AS:66781
 b=TIAS:96000
+b=RS:800
+b=RR:2400