diff --git a/README.md b/README.md
index 9299317d..edb8988b 100644
--- a/README.md
+++ b/README.md
@@ -120,7 +120,7 @@ https://pkg.go.dev/github.com/bluenviron/gortsplib/v3#pkg-index
 
 Related projects
 
-* rtsp-simple-server https://github.com/aler9/rtsp-simple-server
+* MediaMTX https://github.com/aler9/mediamtx
 * pion/sdp (SDP library used internally) https://github.com/pion/sdp
 * pion/rtp (RTP library used internally) https://github.com/pion/rtp
 * pion/rtcp (RTCP library used internally) https://github.com/pion/rtcp
diff --git a/client.go b/client.go
index 2a1489e6..91bab5f7 100644
--- a/client.go
+++ b/client.go
@@ -1494,7 +1494,7 @@ func (c *Client) doPlay(ra *headers.Range, isSwitchingProtocol bool) (*base.Resp
 		return nil, err
 	}
 
-	// open the firewall by sending test packets to the counterpart.
+	// open the firewall by sending empty packets to the counterpart.
 	// do this before sending the request.
 	// don't do this with multicast, otherwise the RTP packet is going to be broadcasted
 	// to all listeners, including us, messing up the stream.
diff --git a/server_play_test.go b/server_play_test.go
index 9692d087..be82ffa6 100644
--- a/server_play_test.go
+++ b/server_play_test.go
@@ -79,14 +79,22 @@ func doDescribe(t *testing.T, conn *conn.Conn) *sdp.SessionDescription {
 	return &desc
 }
 
-func doSetup(t *testing.T, conn *conn.Conn, u string, inTH *headers.Transport) (*base.Response, *headers.Transport) {
+func doSetup(t *testing.T, conn *conn.Conn, u string,
+	inTH *headers.Transport, session string,
+) (*base.Response, *headers.Transport) {
+	h := base.Header{
+		"CSeq":      base.HeaderValue{"1"},
+		"Transport": inTH.Marshal(),
+	}
+
+	if session != "" {
+		h["Session"] = base.HeaderValue{session}
+	}
+
 	res, err := writeReqReadRes(conn, base.Request{
 		Method: base.Setup,
 		URL:    mustParseURL(u),
-		Header: base.Header{
-			"CSeq":      base.HeaderValue{"1"},
-			"Transport": inTH.Marshal(),
-		},
+		Header: h,
 	})
 	require.NoError(t, err)
 	require.Equal(t, base.StatusOK, res.StatusCode)
@@ -124,6 +132,19 @@ func doPause(t *testing.T, conn *conn.Conn, u string, session string) {
 	require.Equal(t, base.StatusOK, res.StatusCode)
 }
 
+func doTeardown(t *testing.T, conn *conn.Conn, u string, session string) {
+	res, err := writeReqReadRes(conn, base.Request{
+		Method: base.Teardown,
+		URL:    mustParseURL(u),
+		Header: base.Header{
+			"CSeq":    base.HeaderValue{"1"},
+			"Session": base.HeaderValue{session},
+		},
+	})
+	require.NoError(t, err)
+	require.Equal(t, base.StatusOK, res.StatusCode)
+}
+
 func readSession(t *testing.T, res *base.Response) string {
 	var sx headers.Session
 	err := sx.Unmarshal(res.Header["Session"])
@@ -249,7 +270,7 @@ func TestServerPlayPath(t *testing.T) {
 			res, _ := doSetup(t, conn,
 				strings.ReplaceAll(ca.setupURL, "[control]", "/"+
 					relativeControlAttribute(desc.MediaDescriptions[1])),
-				th)
+				th, "")
 
 			session := readSession(t, res)
 
@@ -614,7 +635,7 @@ func TestServerPlay(t *testing.T) {
 				inTH.InterleavedIDs = &[2]int{4, 5}
 			}
 
-			res, th := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+			res, th := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 			var l1 net.PacketConn
 			var l2 net.PacketConn
@@ -779,16 +800,7 @@ func TestServerPlay(t *testing.T) {
 				require.Equal(t, base.StatusOK, res.StatusCode)
 			}
 
-			res, err = writeReqReadRes(conn, base.Request{
-				Method: base.Teardown,
-				URL:    mustParseURL("rtsp://" + listenIP + ":8554/teststream"),
-				Header: base.Header{
-					"CSeq":    base.HeaderValue{"6"},
-					"Session": base.HeaderValue{session},
-				},
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doTeardown(t, conn, "rtsp://"+listenIP+":8554/teststream", session)
 
 			<-sessionClosed
 
@@ -883,7 +895,7 @@ func TestServerPlayDecodeErrors(t *testing.T) {
 				inTH.InterleavedIDs = &[2]int{0, 1}
 			}
 
-			res, resTH := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+			res, resTH := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 			var l1 net.PacketConn
 			var l2 net.PacketConn
@@ -995,7 +1007,7 @@ func TestServerPlayRTCPReport(t *testing.T) {
 				inTH.InterleavedIDs = &[2]int{0, 1}
 			}
 
-			res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+			res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 			var l1 net.PacketConn
 			var l2 net.PacketConn
@@ -1054,16 +1066,7 @@ func TestServerPlayRTCPReport(t *testing.T) {
 				OctetCount:  2,
 			}, packets[0])
 
-			res, err = writeReqReadRes(conn, base.Request{
-				Method: base.Teardown,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":    base.HeaderValue{"4"},
-					"Session": base.HeaderValue{session},
-				},
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doTeardown(t, conn, "rtsp://localhost:8554/teststream", session)
 		})
 	}
 }
@@ -1190,7 +1193,7 @@ func TestServerPlayTCPResponseBeforeFrames(t *testing.T) {
 		InterleavedIDs: &[2]int{0, 1},
 	}
 
-	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 	session := readSession(t, res)
 
@@ -1251,7 +1254,7 @@ func TestServerPlayPlayPlay(t *testing.T) {
 		ClientPorts: &[2]int{30450, 30451},
 	}
 
-	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 	session := readSession(t, res)
 
@@ -1340,7 +1343,7 @@ func TestServerPlayPlayPausePlay(t *testing.T) {
 		InterleavedIDs: &[2]int{0, 1},
 	}
 
-	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 	session := readSession(t, res)
 
@@ -1426,7 +1429,7 @@ func TestServerPlayPlayPausePause(t *testing.T) {
 		InterleavedIDs: &[2]int{0, 1},
 	}
 
-	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 	session := readSession(t, res)
 
@@ -1518,7 +1521,7 @@ func TestServerPlayTimeout(t *testing.T) {
 				inTH.Protocol = headers.TransportProtocolUDP
 			}
 
-			res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+			res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 			session := readSession(t, res)
 
@@ -1605,7 +1608,7 @@ func TestServerPlayWithoutTeardown(t *testing.T) {
 				inTH.InterleavedIDs = &[2]int{0, 1}
 			}
 
-			res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+			res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 			session := readSession(t, res)
 
@@ -1678,7 +1681,7 @@ func TestServerPlayUDPChangeConn(t *testing.T) {
 			ClientPorts: &[2]int{35466, 35467},
 		}
 
-		res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+		res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 		session := readSession(t, res)
 
@@ -1761,7 +1764,7 @@ func TestServerPlayPartialMedias(t *testing.T) {
 		InterleavedIDs: &[2]int{4, 5},
 	}
 
-	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 	session := readSession(t, res)
 
@@ -1795,7 +1798,7 @@ func TestServerPlayAdditionalInfos(t *testing.T) {
 			InterleavedIDs: &[2]int{0, 1},
 		}
 
-		res, th := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+		res, th := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 		ssrcs := make([]*uint32, 2)
 		ssrcs[0] = th.SSRC
@@ -1815,21 +1818,8 @@ func TestServerPlayAdditionalInfos(t *testing.T) {
 
 		session := readSession(t, res)
 
-		res, err = writeReqReadRes(conn, base.Request{
-			Method: base.Setup,
-			URL:    mustParseURL(absoluteControlAttribute(desc.MediaDescriptions[1])),
-			Header: base.Header{
-				"CSeq":      base.HeaderValue{"3"},
-				"Transport": inTH.Marshal(),
-				"Session":   base.HeaderValue{session},
-			},
-		})
-		require.NoError(t, err)
-		require.Equal(t, base.StatusOK, res.StatusCode)
+		_, th = doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[1]), inTH, session)
 
-		th = &headers.Transport{}
-		err = th.Unmarshal(res.Header["Transport"])
-		require.NoError(t, err)
 		ssrcs[1] = th.SSRC
 
 		doPlay(t, conn, "rtsp://localhost:8554/teststream", session)
@@ -2035,26 +2025,13 @@ func TestServerPlayNoInterleavedIDs(t *testing.T) {
 		Protocol: headers.TransportProtocolTCP,
 	}
 
-	res, th := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+	res, th := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 	require.Equal(t, &[2]int{0, 1}, th.InterleavedIDs)
 
 	session := readSession(t, res)
 
-	res, err = writeReqReadRes(conn, base.Request{
-		Method: base.Setup,
-		URL:    mustParseURL(absoluteControlAttribute(desc.MediaDescriptions[1])),
-		Header: base.Header{
-			"CSeq":      base.HeaderValue{"3"},
-			"Transport": inTH.Marshal(),
-			"Session":   base.HeaderValue{session},
-		},
-	})
-	require.NoError(t, err)
-	require.Equal(t, base.StatusOK, res.StatusCode)
-
-	err = th.Unmarshal(res.Header["Transport"])
-	require.NoError(t, err)
+	_, th = doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[1]), inTH, session)
 
 	require.Equal(t, &[2]int{2, 3}, th.InterleavedIDs)
 
diff --git a/server_record_test.go b/server_record_test.go
index dbc78283..631903ae 100644
--- a/server_record_test.go
+++ b/server_record_test.go
@@ -21,7 +21,53 @@ import (
 	"github.com/bluenviron/gortsplib/v3/pkg/sdp"
 )
 
+func doAnnounce(t *testing.T, conn *conn.Conn, u string, medias media.Medias) {
+	res, err := writeReqReadRes(conn, base.Request{
+		Method: base.Announce,
+		URL:    mustParseURL(u),
+		Header: base.Header{
+			"CSeq":         base.HeaderValue{"1"},
+			"Content-Type": base.HeaderValue{"application/sdp"},
+		},
+		Body: mustMarshalMedias(medias),
+	})
+	require.NoError(t, err)
+	require.Equal(t, base.StatusOK, res.StatusCode)
+}
+
+func doRecord(t *testing.T, conn *conn.Conn, u string, session string) {
+	res, err := writeReqReadRes(conn, base.Request{
+		Method: base.Record,
+		URL:    mustParseURL(u),
+		Header: base.Header{
+			"CSeq":    base.HeaderValue{"1"},
+			"Session": base.HeaderValue{session},
+		},
+	})
+	require.NoError(t, err)
+	require.Equal(t, base.StatusOK, res.StatusCode)
+}
+
 func invalidURLAnnounceReq(t *testing.T, control string) base.Request {
+	medi := testH264Media
+	medi.Control = control
+
+	sout := &sdp.SessionDescription{
+		SessionName: psdp.SessionName("Stream"),
+		Origin: psdp.Origin{
+			Username:       "-",
+			NetworkType:    "IN",
+			AddressType:    "IP4",
+			UnicastAddress: "127.0.0.1",
+		},
+		TimeDescriptions: []psdp.TimeDescription{
+			{Timing: psdp.Timing{0, 0}}, //nolint:govet
+		},
+		MediaDescriptions: []*psdp.MediaDescription{medi.Marshal()},
+	}
+
+	byts, _ := sout.Marshal()
+
 	return base.Request{
 		Method: base.Announce,
 		URL:    mustParseURL("rtsp://localhost:8554/teststream"),
@@ -29,27 +75,7 @@ func invalidURLAnnounceReq(t *testing.T, control string) base.Request {
 			"CSeq":         base.HeaderValue{"1"},
 			"Content-Type": base.HeaderValue{"application/sdp"},
 		},
-		Body: func() []byte {
-			medi := testH264Media
-			medi.Control = control
-
-			sout := &sdp.SessionDescription{
-				SessionName: psdp.SessionName("Stream"),
-				Origin: psdp.Origin{
-					Username:       "-",
-					NetworkType:    "IN",
-					AddressType:    "IP4",
-					UnicastAddress: "127.0.0.1",
-				},
-				TimeDescriptions: []psdp.TimeDescription{
-					{Timing: psdp.Timing{0, 0}}, //nolint:govet
-				},
-				MediaDescriptions: []*psdp.MediaDescription{medi.Marshal()},
-			}
-
-			byts, _ := sout.Marshal()
-			return byts
-		}(),
+		Body: byts,
 	}
 }
 
@@ -276,20 +302,11 @@ func TestServerRecordPath(t *testing.T) {
 				InterleavedIDs: &[2]int{0, 1},
 			}
 
-			res, _ = doSetup(t, conn, ca.setupURL, th)
+			res, _ = doSetup(t, conn, ca.setupURL, th, "")
 
 			session := readSession(t, res)
 
-			res, err = writeReqReadRes(conn, base.Request{
-				Method: base.Record,
-				URL:    mustParseURL(ca.announceURL),
-				Header: base.Header{
-					"CSeq":    base.HeaderValue{"3"},
-					"Session": base.HeaderValue{session},
-				},
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doRecord(t, conn, ca.announceURL, session)
 		})
 	}
 }
@@ -328,17 +345,7 @@ func TestServerRecordErrorSetupMediaTwice(t *testing.T) {
 	medias := media.Medias{testH264Media}
 	resetMediaControls(medias)
 
-	res, err := writeReqReadRes(conn, base.Request{
-		Method: base.Announce,
-		URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-		Header: base.Header{
-			"CSeq":         base.HeaderValue{"1"},
-			"Content-Type": base.HeaderValue{"application/sdp"},
-		},
-		Body: mustMarshalMedias(medias),
-	})
-	require.NoError(t, err)
-	require.Equal(t, base.StatusOK, res.StatusCode)
+	doAnnounce(t, conn, "rtsp://localhost:8554/teststream", medias)
 
 	inTH := &headers.Transport{
 		Protocol: headers.TransportProtocolTCP,
@@ -353,28 +360,30 @@ func TestServerRecordErrorSetupMediaTwice(t *testing.T) {
 		InterleavedIDs: &[2]int{0, 1},
 	}
 
-	res, _ = doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH)
+	res, _ := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH, "")
 
 	session := readSession(t, res)
 
+	inTH = &headers.Transport{
+		Protocol: headers.TransportProtocolTCP,
+		Delivery: func() *headers.TransportDelivery {
+			v := headers.TransportDeliveryUnicast
+			return &v
+		}(),
+		Mode: func() *headers.TransportMode {
+			v := headers.TransportModeRecord
+			return &v
+		}(),
+		InterleavedIDs: &[2]int{2, 3},
+	}
+
 	res, err = writeReqReadRes(conn, base.Request{
 		Method: base.Setup,
 		URL:    mustParseURL("rtsp://localhost:8554/teststream/" + medias[0].Control),
 		Header: base.Header{
-			"CSeq": base.HeaderValue{"3"},
-			"Transport": headers.Transport{
-				Protocol: headers.TransportProtocolTCP,
-				Delivery: func() *headers.TransportDelivery {
-					v := headers.TransportDeliveryUnicast
-					return &v
-				}(),
-				Mode: func() *headers.TransportMode {
-					v := headers.TransportModeRecord
-					return &v
-				}(),
-				InterleavedIDs: &[2]int{2, 3},
-			}.Marshal(),
-			"Session": base.HeaderValue{session},
+			"CSeq":      base.HeaderValue{"3"},
+			"Transport": inTH.Marshal(),
+			"Session":   base.HeaderValue{session},
 		},
 	})
 	require.NoError(t, err)
@@ -439,17 +448,7 @@ func TestServerRecordErrorRecordPartialMedias(t *testing.T) {
 	}
 	resetMediaControls(medias)
 
-	res, err := writeReqReadRes(conn, base.Request{
-		Method: base.Announce,
-		URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-		Header: base.Header{
-			"CSeq":         base.HeaderValue{"1"},
-			"Content-Type": base.HeaderValue{"application/sdp"},
-		},
-		Body: mustMarshalMedias(medias),
-	})
-	require.NoError(t, err)
-	require.Equal(t, base.StatusOK, res.StatusCode)
+	doAnnounce(t, conn, "rtsp://localhost:8554/teststream", medias)
 
 	inTH := &headers.Transport{
 		Protocol: headers.TransportProtocolTCP,
@@ -464,7 +463,7 @@ func TestServerRecordErrorRecordPartialMedias(t *testing.T) {
 		InterleavedIDs: &[2]int{0, 1},
 	}
 
-	res, _ = doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH)
+	res, _ := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH, "")
 
 	session := readSession(t, res)
 
@@ -601,17 +600,7 @@ func TestServerRecord(t *testing.T) {
 			}
 			resetMediaControls(medias)
 
-			res, err := writeReqReadRes(conn, base.Request{
-				Method: base.Announce,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":         base.HeaderValue{"1"},
-					"Content-Type": base.HeaderValue{"application/sdp"},
-				},
-				Body: mustMarshalMedias(medias),
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doAnnounce(t, conn, "rtsp://localhost:8554/teststream", medias)
 
 			<-sessionOpened
 
@@ -648,29 +637,16 @@ func TestServerRecord(t *testing.T) {
 					inTH.InterleavedIDs = &[2]int{2 + i*2, 3 + i*2}
 				}
 
-				res, _ := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[i].Control, inTH)
+				res, th := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[i].Control, inTH, "")
 
 				session = readSession(t, res)
 
-				var th headers.Transport
-				err = th.Unmarshal(res.Header["Transport"])
-				require.NoError(t, err)
-
 				if transport == "udp" {
 					serverPorts[i] = th.ServerPorts
 				}
 			}
 
-			res, err = writeReqReadRes(conn, base.Request{
-				Method: base.Record,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":    base.HeaderValue{"3"},
-					"Session": base.HeaderValue{session},
-				},
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doRecord(t, conn, "rtsp://localhost:8554/teststream", session)
 
 			for i := 0; i < 2; i++ {
 				// server -> client (direct)
@@ -734,16 +710,7 @@ func TestServerRecord(t *testing.T) {
 				}
 			}
 
-			res, err = writeReqReadRes(conn, base.Request{
-				Method: base.Teardown,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":    base.HeaderValue{"3"},
-					"Session": base.HeaderValue{session},
-				},
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doTeardown(t, conn, "rtsp://localhost:8554/teststream", session)
 
 			<-sessionClosed
 
@@ -795,17 +762,7 @@ func TestServerRecordErrorInvalidProtocol(t *testing.T) {
 	medias := media.Medias{testH264Media}
 	resetMediaControls(medias)
 
-	res, err := writeReqReadRes(conn, base.Request{
-		Method: base.Announce,
-		URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-		Header: base.Header{
-			"CSeq":         base.HeaderValue{"1"},
-			"Content-Type": base.HeaderValue{"application/sdp"},
-		},
-		Body: mustMarshalMedias(medias),
-	})
-	require.NoError(t, err)
-	require.Equal(t, base.StatusOK, res.StatusCode)
+	doAnnounce(t, conn, "rtsp://localhost:8554/teststream", medias)
 
 	inTH := &headers.Transport{
 		Delivery: func() *headers.TransportDelivery {
@@ -820,24 +777,11 @@ func TestServerRecordErrorInvalidProtocol(t *testing.T) {
 		ClientPorts: &[2]int{35466, 35467},
 	}
 
-	res, _ = doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH)
+	res, _ := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH, "")
 
 	session := readSession(t, res)
 
-	var th headers.Transport
-	err = th.Unmarshal(res.Header["Transport"])
-	require.NoError(t, err)
-
-	res, err = writeReqReadRes(conn, base.Request{
-		Method: base.Record,
-		URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-		Header: base.Header{
-			"CSeq":    base.HeaderValue{"3"},
-			"Session": base.HeaderValue{session},
-		},
-	})
-	require.NoError(t, err)
-	require.Equal(t, base.StatusOK, res.StatusCode)
+	doRecord(t, conn, "rtsp://localhost:8554/teststream", session)
 
 	err = conn.WriteInterleavedFrame(&base.InterleavedFrame{
 		Channel: 0,
@@ -885,17 +829,7 @@ func TestServerRecordRTCPReport(t *testing.T) {
 	medias := media.Medias{testH264Media}
 	resetMediaControls(medias)
 
-	res, err := writeReqReadRes(conn, base.Request{
-		Method: base.Announce,
-		URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-		Header: base.Header{
-			"CSeq":         base.HeaderValue{"1"},
-			"Content-Type": base.HeaderValue{"application/sdp"},
-		},
-		Body: mustMarshalMedias(medias),
-	})
-	require.NoError(t, err)
-	require.Equal(t, base.StatusOK, res.StatusCode)
+	doAnnounce(t, conn, "rtsp://localhost:8554/teststream", medias)
 
 	l1, err := net.ListenPacket("udp", "localhost:34556")
 	require.NoError(t, err)
@@ -918,24 +852,11 @@ func TestServerRecordRTCPReport(t *testing.T) {
 		ClientPorts: &[2]int{34556, 34557},
 	}
 
-	res, _ = doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH)
+	res, th := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH, "")
 
 	session := readSession(t, res)
 
-	var th headers.Transport
-	err = th.Unmarshal(res.Header["Transport"])
-	require.NoError(t, err)
-
-	res, err = writeReqReadRes(conn, base.Request{
-		Method: base.Record,
-		URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-		Header: base.Header{
-			"CSeq":    base.HeaderValue{"3"},
-			"Session": base.HeaderValue{session},
-		},
-	})
-	require.NoError(t, err)
-	require.Equal(t, base.StatusOK, res.StatusCode)
+	doRecord(t, conn, "rtsp://localhost:8554/teststream", session)
 
 	byts, _ := (&rtp.Packet{
 		Header: rtp.Header{
@@ -1051,17 +972,7 @@ func TestServerRecordTimeout(t *testing.T) {
 			medias := media.Medias{testH264Media}
 			resetMediaControls(medias)
 
-			res, err := writeReqReadRes(conn, base.Request{
-				Method: base.Announce,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":         base.HeaderValue{"1"},
-					"Content-Type": base.HeaderValue{"application/sdp"},
-				},
-				Body: mustMarshalMedias(medias),
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doAnnounce(t, conn, "rtsp://localhost:8554/teststream", medias)
 
 			inTH := &headers.Transport{
 				Delivery: func() *headers.TransportDelivery {
@@ -1082,24 +993,11 @@ func TestServerRecordTimeout(t *testing.T) {
 				inTH.InterleavedIDs = &[2]int{0, 1}
 			}
 
-			res, _ = doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH)
+			res, _ := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH, "")
 
 			session := readSession(t, res)
 
-			var th headers.Transport
-			err = th.Unmarshal(res.Header["Transport"])
-			require.NoError(t, err)
-
-			res, err = writeReqReadRes(conn, base.Request{
-				Method: base.Record,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":    base.HeaderValue{"3"},
-					"Session": base.HeaderValue{session},
-				},
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doRecord(t, conn, "rtsp://localhost:8554/teststream", session)
 
 			<-sessionClosed
 
@@ -1163,17 +1061,7 @@ func TestServerRecordWithoutTeardown(t *testing.T) {
 			medias := media.Medias{testH264Media}
 			resetMediaControls(medias)
 
-			res, err := writeReqReadRes(conn, base.Request{
-				Method: base.Announce,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":         base.HeaderValue{"1"},
-					"Content-Type": base.HeaderValue{"application/sdp"},
-				},
-				Body: mustMarshalMedias(medias),
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doAnnounce(t, conn, "rtsp://localhost:8554/teststream", medias)
 
 			inTH := &headers.Transport{
 				Delivery: func() *headers.TransportDelivery {
@@ -1194,24 +1082,11 @@ func TestServerRecordWithoutTeardown(t *testing.T) {
 				inTH.InterleavedIDs = &[2]int{0, 1}
 			}
 
-			res, _ = doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH)
+			res, _ := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH, "")
 
 			session := readSession(t, res)
 
-			var th headers.Transport
-			err = th.Unmarshal(res.Header["Transport"])
-			require.NoError(t, err)
-
-			res, err = writeReqReadRes(conn, base.Request{
-				Method: base.Record,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":    base.HeaderValue{"3"},
-					"Session": base.HeaderValue{session},
-				},
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doRecord(t, conn, "rtsp://localhost:8554/teststream", session)
 
 			nconn.Close()
 
@@ -1265,17 +1140,7 @@ func TestServerRecordUDPChangeConn(t *testing.T) {
 		medias := media.Medias{testH264Media}
 		resetMediaControls(medias)
 
-		res, err := writeReqReadRes(conn, base.Request{
-			Method: base.Announce,
-			URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-			Header: base.Header{
-				"CSeq":         base.HeaderValue{"1"},
-				"Content-Type": base.HeaderValue{"application/sdp"},
-			},
-			Body: mustMarshalMedias(medias),
-		})
-		require.NoError(t, err)
-		require.Equal(t, base.StatusOK, res.StatusCode)
+		doAnnounce(t, conn, "rtsp://localhost:8554/teststream", medias)
 
 		inTH := &headers.Transport{
 			Delivery: func() *headers.TransportDelivery {
@@ -1290,20 +1155,11 @@ func TestServerRecordUDPChangeConn(t *testing.T) {
 			ClientPorts: &[2]int{35466, 35467},
 		}
 
-		res, _ = doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH)
+		res, _ := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH, "")
 
 		session := readSession(t, res)
 
-		res, err = writeReqReadRes(conn, base.Request{
-			Method: base.Record,
-			URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-			Header: base.Header{
-				"CSeq":    base.HeaderValue{"3"},
-				"Session": base.HeaderValue{session},
-			},
-		})
-		require.NoError(t, err)
-		require.Equal(t, base.StatusOK, res.StatusCode)
+		doRecord(t, conn, "rtsp://localhost:8554/teststream", session)
 
 		sxID = session
 	}()
@@ -1412,17 +1268,7 @@ func TestServerRecordDecodeErrors(t *testing.T) {
 			}}
 			resetMediaControls(medias)
 
-			res, err := writeReqReadRes(conn, base.Request{
-				Method: base.Announce,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":         base.HeaderValue{"1"},
-					"Content-Type": base.HeaderValue{"application/sdp"},
-				},
-				Body: mustMarshalMedias(medias),
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doAnnounce(t, conn, "rtsp://localhost:8554/teststream", medias)
 
 			inTH := &headers.Transport{
 				Delivery: func() *headers.TransportDelivery {
@@ -1456,24 +1302,11 @@ func TestServerRecordDecodeErrors(t *testing.T) {
 				defer l2.Close()
 			}
 
-			res, _ = doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH)
+			res, resTH := doSetup(t, conn, "rtsp://localhost:8554/teststream/"+medias[0].Control, inTH, "")
 
 			session := readSession(t, res)
 
-			var resTH headers.Transport
-			err = resTH.Unmarshal(res.Header["Transport"])
-			require.NoError(t, err)
-
-			res, err = writeReqReadRes(conn, base.Request{
-				Method: base.Record,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream"),
-				Header: base.Header{
-					"CSeq":    base.HeaderValue{"3"},
-					"Session": base.HeaderValue{session},
-				},
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
+			doRecord(t, conn, "rtsp://localhost:8554/teststream", session)
 
 			switch { //nolint:dupl
 			case ca.proto == "udp" && ca.name == "rtp invalid":
diff --git a/server_session_media.go b/server_session_media.go
index c1b48302..83439cba 100644
--- a/server_session_media.go
+++ b/server_session_media.go
@@ -92,7 +92,7 @@ func (sm *serverSessionMedia) start() {
 			// readers can send RTCP packets only
 			sm.ss.s.udpRTCPListener.addClient(sm.ss.author.ip(), sm.udpRTCPReadPort, sm)
 		} else {
-			// open the firewall by sending test packets to the counterpart.
+			// open the firewall by sending empty packets to the counterpart.
 			sm.ss.WritePacketRTP(sm.media, &rtp.Packet{Header: rtp.Header{Version: 2}})
 			sm.ss.WritePacketRTCP(sm.media, &rtcp.ReceiverReport{})
 
diff --git a/server_test.go b/server_test.go
index 82d9778d..16b36fa6 100644
--- a/server_test.go
+++ b/server_test.go
@@ -376,7 +376,7 @@ func TestServerErrorMethodNotImplemented(t *testing.T) {
 					InterleavedIDs: &[2]int{0, 1},
 				}
 
-				res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+				res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 				session = readSession(t, res)
 			}
@@ -468,7 +468,7 @@ func TestServerErrorTCPTwoConnOneSession(t *testing.T) {
 		InterleavedIDs: &[2]int{0, 1},
 	}
 
-	res, _ := doSetup(t, conn1, absoluteControlAttribute(desc1.MediaDescriptions[0]), inTH)
+	res, _ := doSetup(t, conn1, absoluteControlAttribute(desc1.MediaDescriptions[0]), inTH, "")
 
 	session := readSession(t, res)
 
@@ -559,7 +559,7 @@ func TestServerErrorTCPOneConnTwoSessions(t *testing.T) {
 		InterleavedIDs: &[2]int{0, 1},
 	}
 
-	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 	session := readSession(t, res)
 
@@ -745,7 +745,7 @@ func TestServerGetSetParameter(t *testing.T) {
 					InterleavedIDs: &[2]int{0, 1},
 				}
 
-				res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+				res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 				session = readSession(t, res)
 			}
@@ -887,7 +887,7 @@ func TestServerSessionClose(t *testing.T) {
 		InterleavedIDs: &[2]int{0, 1},
 	}
 
-	doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+	doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 	session.Close()
 	session.Close()
@@ -1027,20 +1027,11 @@ func TestServerSessionTeardown(t *testing.T) {
 		InterleavedIDs: &[2]int{0, 1},
 	}
 
-	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH)
+	res, _ := doSetup(t, conn, absoluteControlAttribute(desc.MediaDescriptions[0]), inTH, "")
 
 	session := readSession(t, res)
 
-	res, err = writeReqReadRes(conn, base.Request{
-		Method: base.Teardown,
-		URL:    mustParseURL("rtsp://localhost:8554/"),
-		Header: base.Header{
-			"CSeq":    base.HeaderValue{"2"},
-			"Session": base.HeaderValue{session},
-		},
-	})
-	require.NoError(t, err)
-	require.Equal(t, base.StatusOK, res.StatusCode)
+	doTeardown(t, conn, "rtsp://localhost:8554/", session)
 
 	res, err = writeReqReadRes(conn, base.Request{
 		Method: base.Options,