Contents

• Media Capture and streams
• Peer to peer Connection
  • RTCPeerConnection, RTCConfiguration, ICE, Offer/Answer, states
• RTP Media API
  • RTCRtpSender
  • RTCRtpReceiver
  • RTCRtpTransreciver
  • SDP Semantics
• RTCDTLS Transport
• RTCIceCandidate
  • ICE gathering

• RTCIceTransport Interface
• Peer-to-peer Data API
• Peer-to-peer DTMF
• Statistics

Peer-to-peer connections

creates p2p communication channel

RTCConfiguration Dictionary

dictionary RTCConfiguration {
  sequence<RTCIceServer> iceServers;
  RTCIceTransportPolicy iceTransportPolicy;
  RTCBundlePolicy bundlePolicy;
  RTCRtcpMuxPolicy rtcpMuxPolicy;
  DOMString peerIdentity;
  sequence<RTCCertificate> certificates;
  [EnforceRange] octet iceCandidatePoolSize = 0;
};

RTCIceCredentialType Enum

enum RTCIceCredentialType {
  "password",
  "oauth"
};

supports OAuth 2.0 based authentication. The application, acting as the OAuth Client, is responsible for refreshing the credential information and updating the ICE Agent with fresh new credentials before the accessToken expires. The OAuth Client can use the RTCPeerConnection setConfiguration method to periodically refresh the TURN credentials.

RTCOAuthCredential Dictionary

Describes the OAuth auth credential information which is used by the STUN/TURN client (inside the ICE Agent) to authenticate against a STUN/TURN server

dictionary RTCOAuthCredential {
  required DOMString macKey;
  required DOMString accessToken;
};

RTCIceServer Dictionary

Describes the STUN and TURN servers that can be used by the ICE Agent to establish a connection with a peer.

dictionary RTCIceServer { required (DOMString or sequence<DOMString>) urls; DOMString username; (DOMString or RTCOAuthCredential) credential; RTCIceCredentialType credentialType = "password"; };

Example :

 [{urls: 'stun:stun1.example.net'},
  {urls: ['turns:turn.example.org', 'turn:turn.example.net'],
    username: 'user',
    credential: 'myPassword',
    credentialType: 'password'},
  {urls: 'turns:turn2.example.net',
    username: '22BIjxU93h/IgwEb',
    credential: {
      macKey: 'WmtzanB3ZW9peFhtdm42NzUzNG0=',
      accessToken: 'AAwg3kPHWPfvk9bDFL936wYvkoctMADzQ5VhNDgeMR3+ZlZ35byg972fW8QjpEl7bx91YLBPFsIhsxloWcXPhA=='
    },
    credentialType: 'oauth'}
];

RTCIceTransportPolicy Enum

ICE candidate policy [JSEP] to select candidates for the ICE connectivity checks

• relay – use only media relay candidates such as candidates passing through a TURN server. It prevents the remote endpoint/unknown caller from learning the user’s IP addresses

• all – ICE Agent can use any type of candidate when this value is specified.

RTCBundlePolicy Enum

• balanced – Gather ICE candidates for each media type (audio, video, and data). If the remote endpoint is not bundle-aware, negotiate only one audio and video track on separate transports.

• max-compat – Gather ICE candidates for each track. If the remote endpoint is not bundle-aware, negotiate all media tracks on separate transports.

• max-bundle – Gather ICE candidates for only one track. If the remote endpoint is not bundle-aware, negotiate only one media track. If the remote endpoint is bundle-aware, all media tracks and data channels are bundled onto the same transport.

If the value of configuration.bundlePolicy is set and its value differs from the connection’s bundle policy, throw an InvalidModificationError.

RTCRtcpMuxPolicy Enum

what ICE candidates are gathered to support non-multiplexed RTCP.

• negotiate – Gather ICE candidates for both RTP and RTCP candidates. If the remote-endpoint is capable of multiplexing RTCP, multiplex RTCP on the RTP candidates. If it is not, use both the RTP and RTCP candidates separately.

• require – Gather ICE candidates only for RTP and multiplex RTCP on the RTP candidates. If the remote endpoint is not capable of rtcp-mux, session negotiation will fail.

If the value of configuration.rtcpMuxPolicy is set and its value differs from the connection’s rtcpMux policy, throw an InvalidModificationError. If the value is “negotiate” and the user agent does not implement non-muxed RTCP, throw a NotSupportedError.

Offer/Answer Options – VoiceActivityDetection

dictionary RTCOfferAnswerOptions {
  boolean voiceActivityDetection = true;
};

capable of detecting “silence”

dictionary RTCOfferOptions : RTCOfferAnswerOptions {
  boolean iceRestart = false;
};

dictionary RTCAnswerOptions : RTCOfferAnswerOptions {};

An RTCPeerConnection object has a signaling state, a connection state, an ICE gathering state, and an ICE connection state.

RTCSignalingState Enum

“stable”,
“have-local-offer”,
“have-remote-offer”,
“have-local-pranswer”,
“have-remote-pranswer”,
“closed”

RTCIceGatheringState Enum

“closed”,
“failed”,
“disconnected”,
“new”,
“connecting”,
“connected”

RTCIceConnectionState Enum

“closed”,
“failed”,
“disconnected”,
“new”,
“checking”,
“completed”,
“connected”

An RTCPeerConnection object has an operations chain which ensures that only one asynchronous operation in the chain executes concurrently.

Also an RTCPeerConnection object MUST not be garbage collected as long as any event can cause an event handler to be triggered on the object. When the object’s internal slot is true ie closed, no such event handler can be triggered and it is therefore safe to garbage collect the object.

RTCPeerConnection Interface

interface RTCPeerConnection : EventTarget {

Promise<RTCSessionDescriptionInit> createOffer(optional RTCOfferOptions options);

Promise<RTCSessionDescriptionInit> createAnswer(optional RTCAnswerOptions options);

Promise<void> setLocalDescription(optional RTCSessionDescriptionInit description);
  
readonly attribute RTCSessionDescription? localDescription;
readonly attribute RTCSessionDescription? currentLocalDescription;
readonly attribute RTCSessionDescription? pendingLocalDescription;
  
Promise<void> setRemoteDescription(optional RTCSessionDescriptionInit description);
  
readonly attribute RTCSessionDescription? remoteDescription;
readonly attribute RTCSessionDescription? currentRemoteDescription;
readonly attribute RTCSessionDescription? pendingRemoteDescription;

Promise<void> addIceCandidate(optional RTCIceCandidateInit candidate);
readonly attribute RTCSignalingState signalingState;
readonly attribute RTCIceGatheringState iceGatheringState;
readonly attribute RTCIceConnectionState iceConnectionState;
readonly attribute RTCPeerConnectionState connectionState;
readonly attribute boolean? canTrickleIceCandidates;
void restartIce();
static sequence<RTCIceServer> getDefaultIceServers();

RTCConfiguration getConfiguration();
void setConfiguration(RTCConfiguration configuration);
void close();

attribute EventHandler onnegotiationneeded;
attribute EventHandler onicecandidate;
attribute EventHandler onicecandidateerror;
attribute EventHandler onsignalingstatechange;
attribute EventHandler oniceconnectionstatechange;
attribute EventHandler onicegatheringstatechange;
attribute EventHandler onconnectionstatechange;
};

CreateOffer() – generates a blob of SDP that contains an RFC 3264 offer with the supported configurations for the session, including

• descriptions of the local MediaStreamTracks attached to this RTCPeerConnection,
• codec/RTP/RTCP capabilities
• ICE agent (usernameFragment, password , local candiadtes etc )
• DTLS connection

var pc = new RTCPeerConnection();
pc.createOffer({
     mandatory: {
        OfferToReceiveAudio: true,
        OfferToReceiveVideo: true
    },
    optional: [{
        VoiceActivityDetection: false
    }]
}).then(function(offer) {
	return pc.setLocalDescription(offer);
})
.then(function() {
// Send the offer to the remote through signaling server
})
.catch(handleError);

CreateAnswer() – generates an SDPanswer with the supported configuration for the session that is compatible with the parameters in the remote configuration

var pc = new RTCPeerConnection();
pc.createAnswer({
  OfferToReceiveAudio: true
  OfferToReceiveVideo: true
})
.then(function(answer) {
  return pc.setLocalDescription(answer);
})
.then(function() {
  // Send the answer to the remote through signaling server
})
.catch(handleError);

Codec preferences of an m= section’s associated transceiver is said to be the value of the RTCRtpTranceiver with the following filtering applied

• If direction is “sendrecv”, exclude any codecs not included in the intersection of RTCRtpSender.getCapabilities(kind).codecs and RTCRtpReceiver.getCapabilities(kind).codecs.
• If direction is “sendonly”, exclude any codecs not included in RTCRtpSender.getCapabilities(kind).codecs.
• If direction is “recvonly”, exclude any codecs not included in RTCRtpReceiver.getCapabilities(kind).codecs.

Legacy Interface Extensions

partial interface RTCPeerConnection {
 
Promise<void> createOffer(
 RTCSessionDescriptionCallback successCallback,
 RTCPeerConnectionErrorCallback failureCallback,
 optional RTCOfferOptions options);
 
Promise<void> setLocalDescription(
optional RTCSessionDescriptionInit description,
VoidFunction successCallback,                                  RTCPeerConnectionErrorCallback failureCallback);

Promise<void> createAnswer(
RTCSessionDescriptionCallback successCallback,
RTCPeerConnectionErrorCallback failureCallback);
  
Promise<void> setRemoteDescription(
optional RTCSessionDescriptionInit description,
VoidFunction successCallback,
                                     RTCPeerConnectionErrorCallback failureCallback);
  
Promise<void> addIceCandidate(
RTCIceCandidateInit candidate,
VoidFunction successCallback,
RTCPeerConnectionErrorCallback failureCallback);
};

Session Description Model

enum RTCSdpType {
  "offer",
  "pranswer",
  "answer",
  "rollback"
};

interface RTCSessionDescription {
  readonly attribute RTCSdpType type;
  readonly attribute DOMString sdp;
  [Default] object toJSON();
};

dictionary RTCSessionDescriptionInit {
  RTCSdpType type;
  DOMString sdp = "";
};

RTCPriorityType
Priority and QoS Model which can be

“very-low”,
“low”,
“medium”,
“high”

RTP Media API

Send and receive MediaStreamTracks over a peer-to-peer connection.
Tracks, when added to an RTCPeerConnection, result in signaling; when this signaling is forwarded to a remote peer, it causes corresponding tracks to be created on the remote side.

RTCRtpSenders objects manages encoding and transmission of MediaStreamTracks .

RTCRtpReceivers objects manage the reception and decoding of MediaStreamTracks. These are associated with one track.

RTCRtpTransceivers interface describes a permanent pairing of an RTCRtpSender and an RTCRtpReceiver.

Each transceiver is uniquely identified using its mid ( media id) property from the corresponding m-line.

They are created implicitly when the application attaches a MediaStreamTrack to an RTCPeerConnection via the addTrack(), or explicitly when the application uses the addTransceiver(). They are also created when a remote description is applied that includes a new media description.

rtpTransceiver = RTCPeerConnection.addTransceiver(trackOrKind, init);

trackOrKind should be either audio or video othereise a TypeError is thrown

init is optional – can contain direction , sendEncodings , streams

RTCPeerConnection Interface

partial interface RTCPeerConnection {
  
sequence<RTCRtpSender> getSenders();
sequence<RTCRtpReceiver> getReceivers();
sequence<RTCRtpTransceiver> getTransceivers();

RTCRtpSender addTrack(MediaStreamTrack track, MediaStream... streams);
void removeTrack(RTCRtpSender sender);
RTCRtpTransceiver addTransceiver((MediaStreamTrack or DOMString) trackOrKind, optional RTCRtpTransceiverInit init);
attribute EventHandler ontrack;
};

RTCRtpTransceiverInit

dictionary RTCRtpTransceiverInit {
  RTCRtpTransceiverDirection direction = "sendrecv";
  sequence<MediaStream> streams = [];
  sequence<RTCRtpEncodingParameters> sendEncodings = [];
};

RTCRtpTransceiverDirection can be either of

“sendrecv”,
“sendonly”,
“recvonly”,
“inactive”,
“stopped”

RTCRtpSender Interface

Allows an application to control how a given MediaStreamTrack is encoded and transmitted to a remote peer.

interface RTCRtpSender {
readonly attribute MediaStreamTrack? track;
readonly attribute RTCDtlsTransport? transport;
readonly attribute RTCDtlsTransport? rtcpTransport;
static RTCRtpCapabilities? getCapabilities(DOMString kind);
Promise<void> setParameters(RTCRtpSendParameters parameters);
RTCRtpSendParameters getParameters();
Promise<void> replaceTrack(MediaStreamTrack? withTrack);
void setStreams(MediaStream... streams);
Promise<RTCStatsReport> getStats();
};

RTCRtpParameters Dictionary

dictionary RTCRtpParameters {
  required sequence<RTCRtpHeaderExtensionParameters> headerExtensions;
  required RTCRtcpParameters rtcp;
  required sequence<RTCRtpCodecParameters> codecs;
};

RTCRtpSendParameters Dictionary

dictionary RTCRtpSendParameters : RTCRtpParameters {
  required DOMString transactionId;
  required sequence<RTCRtpEncodingParameters> encodings;
  RTCDegradationPreference degradationPreference = "balanced";
  RTCPriorityType priority = "low";
};

RTCRtpReceiveParameters Dictionary

dictionary RTCRtpReceiveParameters : RTCRtpParameters {
  required sequence<RTCRtpDecodingParameters> encodings;
};

RTCRtpCodingParameters Dictionary

dictionary RTCRtpCodingParameters {
  DOMString rid;
};

RTCRtpDecodingParameters Dictionary

dictionary RTCRtpDecodingParameters : RTCRtpCodingParameters {};

RTCRtpEncodingParameters Dictionary

dictionary RTCRtpEncodingParameters : RTCRtpCodingParameters {
  octet codecPayloadType;
  RTCDtxStatus dtx;
  boolean active = true;
  unsigned long ptime;
  unsigned long maxBitrate;
  double maxFramerate;
  double scaleResolutionDownBy;
};

RTCDtxStatus Enum

disabled- Discontinuous transmission is disabled.
enabled- Discontinuous transmission is enabled if negotiated.

RTCDegradationPreference Enum

enum RTCDegradationPreference {
  "maintain-framerate",
  "maintain-resolution",
  "balanced"
};

RTCRtcpParameters Dictionary

dictionary RTCRtcpParameters {
  DOMString cname;
  boolean reducedSize;
};

RTCRtpHeaderExtensionParameters Dictionary

dictionary RTCRtpHeaderExtensionParameters {
  required DOMString uri;
  required unsigned short id;
  boolean encrypted = false;
};

RTCRtpCodecParameters Dictionary

dictionary RTCRtpCodecParameters {
  required octet payloadType;
  required DOMString mimeType;
  required unsigned long clockRate;
  unsigned short channels;
  DOMString sdpFmtpLine;
};

payloadType – identify this codec.
mimeType – codec MIME media type/subtype. Valid media types and subtypes are listed in [IANA-RTP-2]
clockRate – expressed in Hertz
channels – number of channels (mono=1, stereo=2).
sdpFmtpLine – “format specific parameters” field from the “a=fmtp” line in the SDP corresponding to the codec

RTCRtpCapabilities Dictionary

dictionary RTCRtpCapabilities {
  required sequence<RTCRtpCodecCapability> codecs;
  required sequence<RTCRtpHeaderExtensionCapability> headerExtensions;
};

RTCRtpCodecCapability Dictionary

dictionary RTCRtpCodecCapability {
  required DOMString mimeType;
  required unsigned long clockRate;
  unsigned short channels;
  DOMString sdpFmtpLine;
};

RTCRtpHeaderExtensionCapability Dictionary

dictionary RTCRtpHeaderExtensionCapability {
  DOMString uri;
};

Example JS code to RTCRtpCapabilities

const pc = new RTCPeerConnection();
const transceiver = pc.addTransceiver('audio');
const capabilities = RTCRtpSender.getCapabilities('audio');

Output :

codecs: Array(13)
0: {channels: 2, clockRate: 48000, mimeType: "audio/opus", sdpFmtpLine: "minptime=10;useinbandfec=1"}
1: {channels: 1, clockRate: 16000, mimeType: "audio/ISAC"}
2: {channels: 1, clockRate: 32000, mimeType: "audio/ISAC"}
3: {channels: 1, clockRate: 8000, mimeType: "audio/G722"}
4: {channels: 1, clockRate: 8000, mimeType: "audio/PCMU"}
5: {channels: 1, clockRate: 8000, mimeType: "audio/PCMA"}
6: {channels: 1, clockRate: 32000, mimeType: "audio/CN"}
7: {channels: 1, clockRate: 16000, mimeType: "audio/CN"}
8: {channels: 1, clockRate: 8000, mimeType: "audio/CN"}
9: {channels: 1, clockRate: 48000, mimeType: "audio/telephone-event"}
10: {channels: 1, clockRate: 32000, mimeType: "audio/telephone-event"}
11: {channels: 1, clockRate: 16000, mimeType: "audio/telephone-event"}
12: {channels: 1, clockRate: 8000, mimeType: "audio/telephone-event"}
length: 13

headerExtensions: Array(6)
0: {uri: "urn:ietf:params:rtp-hdrext:ssrc-audio-level"}
1: {uri: "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time"}
2: {uri: "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01"}
3: {uri: "urn:ietf:params:rtp-hdrext:sdes:mid"}
4: {uri: "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id"}
5: {uri: "urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id"}
length: 6

RTCRtpReceiver Interface

allows an application to inspect the receipt of a MediaStreamTrack.

interface RTCRtpReceiver {
  readonly attribute MediaStreamTrack track;
  readonly attribute RTCDtlsTransport? transport;
  readonly attribute RTCDtlsTransport? rtcpTransport;
  static RTCRtpCapabilities? getCapabilities(DOMString kind);
  RTCRtpReceiveParameters getParameters();
  sequence<RTCRtpContributingSource> getContributingSources();
  sequence<RTCRtpSynchronizationSource> getSynchronizationSources();
  Promise<RTCStatsReport> getStats();
};

dictionary RTCRtpContributingSource

dictionary RTCRtpContributingSource {
  required DOMHighResTimeStamp timestamp;
  required unsigned long source;
  double audioLevel;
  required unsigned long rtpTimestamp;
};

dictionary RTCRtpSynchronizationSource

dictionary RTCRtpSynchronizationSource : RTCRtpContributingSource {
  boolean voiceActivityFlag;
};

voiceActivityFlag of type boolean – Only present for audio receivers. Whether the last RTP packet, delivered from this source, contains voice activity (true) or not (false).

RTCRtpTransceiver Interface

Each SDP media section describes one bidirectional SRTP (“Secure Real Time Protocol”) stream. RTCRtpTransceiver describes this permanent pairing of an RTCRtpSender and an RTCRtpReceiver, along with some shared state. It is uniquely identified using its mid property.

Thus it is combination of an RTCRtpSender and an RTCRtpReceiver that share a common mid. An associated transceiver( with mid) is one that’s represented in the last applied session description.

interface RTCRtpTransceiver {

readonly attribute DOMString? mid;
[SameObject] readonly attribute RTCRtpSender sender;
[SameObject] readonly attribute RTCRtpReceiver receiver;

attribute RTCRtpTransceiverDirection direction;
readonly attribute RTCRtpTransceiverDirection? currentDirection;

void stop();

void setCodecPreferences(sequence<RTCRtpCodecCapability> codecs);
};

Method stop() – Irreversibly marks the transceiver as stopping, unless it is already stopped. This will immediately cause the transceiver’s sender to no longer send, and its receiver to no longer receive.
stopping transceiver will cause future calls to createOffer to generate a zero port in the media description for the corresponding transceiver and stopped transceiver will cause future calls to createOffer or createAnswer to generate a zero port in the media description for the corresponding transceiver

Methods setCodecPreferences() – overrides the default codec preferences used by the user agent.

Example setting codec Preferebec for OPUS in audio

peer = new RTCPeerConnection();    
const transceiver = peer.addTransceiver('audio');
const audiocapabilities = RTCRtpSender.getCapabilities('audio');
let codec = [];
codec.push(audiocapabilities.codecs[0]);
transceiver.setCodecPreferences(codec);

Before setting codec preference for OPUS

m=audio 9 UDP/TLS/RTP/SAVPF 111 103 104 9 0 8 106 105 13 110 112 113 126
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
…
a=recvonly
a=rtcp-mux
a=rtpmap:111 opus/48000/2
a=rtcp-fb:111 transport-cc
a=fmtp:111 minptime=10;useinbandfec=1
a=rtpmap:103 ISAC/16000
a=rtpmap:104 ISAC/32000
a=rtpmap:9 G722/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:106 CN/32000
a=rtpmap:105 CN/16000
a=rtpmap:13 CN/8000
a=rtpmap:110 telephone-event/48000
a=rtpmap:112 telephone-event/32000
a=rtpmap:113 telephone-event/16000
a=rtpmap:126 telephone-event/8000

After setting codec preference for OPUS audio

m=audio 9 UDP/TLS/RTP/SAVPF 111
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
…
a=sendrecv
a=msid:hcgvWcGG7WhdzboWk79q39NiO8xkh4ArWhbM f15d77bb-7a6f-4f41-80cd-51a3c40de7b7
a=rtcp-mux
a=rtpmap:111 opus/48000/2
a=rtcp-fb:111 transport-cc
a=fmtp:111 minptime=10;useinbandfec=1

RTCDtlsTransport

Access to information about the Datagram Transport Layer Security (DTLS) transport over which RTP and RTCP packets are sent and received by RTCRtpSender and RTCRtpReceiver objects, as well other data such as SCTP packets sent and received by data channels.
Each RTCDtlsTransport object represents the DTLS transport layer for the RTP or RTCP component of a specific RTCRtpTransceiver, or a group of RTCRtpTransceivers if such a group has been negotiated via [BUNDLE].

interface RTCDtlsTransport : EventTarget {
  [SameObject] readonly attribute RTCIceTransport iceTransport;
  readonly attribute RTCDtlsTransportState state;
  sequence<ArrayBuffer> getRemoteCertificates();
  attribute EventHandler onstatechange;
  attribute EventHandler onerror;
};

RTCDtlsTransportState Enum

“new”- DTLS has not started negotiating yet.
“connecting” – DTLS is in the process of negotiating a secure connection and verifying the remote fingerprint.
“connected”- DTLS has completed negotiation of a secure connection and verified the remote fingerprint.
“closed” – transport has been closed intentionally like close_notify alert, or calling close().
“failed” – transport has failed as the result of an error like failure to validate the remote fingerprint

RTCDtlsFingerprint dictionary

dictionary RTCDtlsFingerprint {
  DOMString algorithm;
  DOMString value;
};

Protocols multiplexed with RTP (e.g. data channel) share its component ID. This represents the component-id value 1 when encoded in candidate-attribute while ICE candadte for RTCP has component-id value 2 when encoded in candidate-attribute.

RTCTrackEvent

The track event uses the RTCTrackEvent interface.

interface RTCTrackEvent : Event {
  readonly attribute RTCRtpReceiver receiver;
  readonly attribute MediaStreamTrack track;
  [SameObject] readonly attribute FrozenArray<MediaStream> streams;
  readonly attribute RTCRtpTransceiver transceiver;
};

dictionary RTCTrackEventInit

dictionary RTCTrackEventInit : EventInit {
  required RTCRtpReceiver receiver;
  required MediaStreamTrack track;
  sequence<MediaStream> streams = [];
  required RTCRtpTransceiver transceiver;
};

RTCIceCandidate

This interface candidate Internet Connectivity Establishment (ICE) configuration used to setup RTCPeerconnection. To facilitate routing of media on given peer connection, both endpoints exchange several candidates and then one candidate out of the lot is chosen which will be then used to initiate the connection.

• candidate – transport address for the candidate that can be used for connectivity checks.
• component – candidate is an RTP or an RTCP candidate
• foundation – unique identifier that is the same for any candidates of the same type , helps optimize ICE performance while prioritizing and correlating candidates that appear on multiple RTCIceTransport objects.
• ip , port
• priority
• protocol – tcp/udp
• relatedAddress , relatedPort
• sdpMid – candidate’s media stream identification tag
• sdpMLineIndex

usernameFragment – randomly-generated username fragment (“ice-ufrag”) which ICE uses for message integrity along with a randomly-generated password (“ice-pwd”).

Interfaces for Connectivity Establishment

describes ICE candidates

interface RTCIceCandidate {
  readonly attribute DOMString candidate;
  readonly attribute DOMString? sdpMid;
  readonly attribute unsigned short? sdpMLineIndex;
  readonly attribute DOMString? foundation;
  readonly attribute RTCIceComponent? component;
  readonly attribute unsigned long? priority;
  readonly attribute DOMString? address;
  readonly attribute RTCIceProtocol? protocol;
  readonly attribute unsigned short? port;
  readonly attribute RTCIceCandidateType? type;
  readonly attribute RTCIceTcpCandidateType? tcpType;
  readonly attribute DOMString? relatedAddress;
  readonly attribute unsigned short? relatedPort;
  readonly attribute DOMString? usernameFragment;
  RTCIceCandidateInit toJSON();
};

RTCIceProtocol can be either tcp or udp

TCP candidate type which can be either of

• active – An active TCP candidate is one for which the transport will attempt to open an outbound connection but will not receive incoming connection requests.
• passive – A passive TCP candidate is one for which the transport will receive incoming connection attempts but not attempt a connection.
• so – An so candidate is one for which the transport will attempt to open a connection simultaneously with its peer.

UDP candidate type

• host – actual direct IP address of the remote peer
• srflx – server reflexive ,  generated by a STUN/TURN server
• prflx – peer reflexive ,IP address comes from a symmetric NAT between the two peers, usually as an additional candidate during trickle ICE
• relay – generated using TURN

ICE Candidate UDP Host

sdpMid: 0, sdpMLineIndex: 0, candidate: candidate:27784895 1 udp 2122260223 192.168.1.114 51577 typ host generation 0 ufrag muSq network-id 1 network-cost 10

sdpMid: 1, sdpMLineIndex: 1, candidate: candidate:27784895 1 udp 2122260223 192.168.1.114 51382 typ host generation 0 ufrag muSq network-id 1 network-cost 10

sdpMid: 2, sdpMLineIndex: 2, candidate: candidate:27784895 1 udp 2122260223 192.168.1.114 53600 typ host generation 0 ufrag muSq network-id 1 network-cost 10

ICE Candidate TCP Host

Notice TCP host camdidates for mid 0 , 1 and 3 for video , audio and data media types

sdpMid: 0, sdpMLineIndex: 0, candidate: candidate:1327761999 1 tcp 1518280447 192.168.1.114 9 typ host tcptype active generation 0 ufrag muSq network-id 1 network-cost 10

sdpMid: 1, sdpMLineIndex: 1, candidate: candidate:1327761999 1 tcp 1518280447 192.168.1.114 9 typ host tcptype active generation 0 ufrag muSq network-id 1 network-cost 10

sdpMid: 2, sdpMLineIndex: 2, candidate: candidate:1327761999 1 tcp 1518280447 192.168.1.114 9 typ host tcptype active generation 0 ufrag muSq network-id 1 network-cost 10

ICE Candidate UDP Srflx

Notice 3 candidates for 3 streams sdpMid 0,1 and 2

sdpMid: 2, sdpMLineIndex: 2, candidate: candidate:2163208203 1 udp 1686052607 117.201.90.218 27177 typ srflx raddr 192.168.1.114 rport 53600 generation 0 ufrag muSq network-id 1 network-cost 10

sdpMid: 1, sdpMLineIndex: 1, candidate: candidate:2163208203 1 udp 1686052607 117.201.90.218 27176 typ srflx raddr 192.168.1.114 rport 51382 generation 0 ufrag muSq network-id 1 network-cost 10

sdpMid: 0, sdpMLineIndex: 0, candidate: candidate:2163208203 1 udp 1686052607 117.201.90.218 27175 typ srflx raddr 192.168.1.114 rport 51577 generation 0 ufrag muSq network-id 1 network-cost 10

ICE Candidate (host)

sdpMid: 0, sdpMLineIndex: 0, candidate: candidate:2880323124 1 udp 2122260223 192.168.1.116 61622 typ host generation 0 ufrag jsPO network-id 1 network-cost 10

usernameFragment – randomly-generated username fragment (“ice-ufrag”) which ICE uses for message integrity along with a randomly-generated password (“ice-pwd”).

a=ice-ufrag:D+yg
a=ice-pwd:2ep6CXO0FP/JfS4ue/dfjeQM
a=ice-options:trickle

RTCPeerConnectionIceEvent

interface RTCPeerConnectionIceEvent : Event {
  readonly attribute RTCIceCandidate? candidate;
  readonly attribute DOMString? url;
};

RTCPeerConnectionIceErrorEvent

interface RTCPeerConnectionIceErrorEvent : Event {
  readonly attribute DOMString hostCandidate;
  readonly attribute DOMString url;
  readonly attribute unsigned short errorCode;
  readonly attribute USVString errorText;
};

RTCIceTransport Interface

Access to information about the ICE transport over which packets are sent and received. Each RTCIceTransport object represents the ICE transport layer for the RTP or RTCP component of a specific RTCRtpTransceiver, or a group of RTCRtpTransceivers if such a group has been negotiated via [BUNDLE].

interface RTCIceTransport : EventTarget {
  readonly attribute RTCIceRole role;
  readonly attribute RTCIceComponent component;
  readonly attribute RTCIceTransportState state;
  readonly attribute RTCIceGathererState gatheringState;
  sequence<RTCIceCandidate> getLocalCandidates();
  sequence<RTCIceCandidate> getRemoteCandidates();
  RTCIceCandidatePair? getSelectedCandidatePair();
  RTCIceParameters? getLocalParameters();
  RTCIceParameters? getRemoteParameters();
  attribute EventHandler onstatechange;
  attribute EventHandler ongatheringstatechange;
  attribute EventHandler onselectedcandidatepairchange;
};

RTCIceParameters Dictionary

dictionary RTCIceParameters {
  DOMString usernameFragment;
  DOMString password;
};

RTCIceCandidatePair Dictionary

dictionary RTCIceCandidatePair {
  RTCIceCandidate local;
  RTCIceCandidate remote;
};

RTCIceGathererState Enum

“new”,
“gathering”,
“complete”

RTCIceTransportState Enum

• “new” – ICE agent is gathering addresses or is waiting to be given remote candidates 
• “checking” –
• “connected” – Found a working candidate pair, but still performing connectivity checks to find a better one.
• “completed” – Found a working candidate pair and done performing connectivity checks.
• “disconnected”,
• “failed”,
• “closed”

RTCIceRole Enum

“unknown”, // agent who role is not yet defined
“controlling”, // controlling agent
“controlled” // controlled agent

RTCIceComponent Enum

“rtp”, // ICE Transport is used for RTP (or RTCP multiplexing)
“rtcp” // ICE Transport is used for RTCP

Peer-to-peer Data API

-tbd

Peer-to-peer DTMF

-tbd

Statistics Model

The browser maintains a set of statistics for monitored objects, in the form of stats objects.
A group of related objects may be referenced by a selector( like MediaStreamTrack that is sent or received by the RTCPeerConnection).

Statistics API extends the RTCPeerConnection interface

partial interface RTCPeerConnection {
  Promise<RTCStatsReport> getStats(optional MediaStreamTrack? selector = null);
  attribute EventHandler onstatsended;
};

Method getStats()- Gathers stats for the given selector and reports the result asynchronously.

RTCStatsReport Object

map between strings that identify the inspected objects (id attribute in RTCStats instances), and their corresponding RTCStats-derived dictionaries.

interface RTCStatsReport {
  readonly maplike<DOMString, object>;
};

RTCStats Dictionary

stats object constructed by inspecting a specific monitored object.

dictionary RTCStats {
  required DOMHighResTimeStamp timestamp;
  required RTCStatsType type;
  required DOMString id;
};

RTCStatsEvent

Constructor (DOMString type, RTCStatsEventInit eventInitDict)]

interface RTCStatsEvent : Event {
  readonly attribute RTCStatsReport report;
};

dictionary RTCStatsEventInit

dictionary RTCStatsEventInit : EventInit {
  required RTCStatsReport report;
};

Stats

• RTCRTPStreamStats, attributes ssrc, kind, transportId, codecId
• RTCReceivedRTPStreamStats, all required attributes from its inherited dictionaries, and also attributes packetsReceived, packetsLost, jitter, packetsDiscarded
• RTCInboundRTPStreamStats, all required attributes from its inherited dictionaries, and also attributes trackId, receiverId, remoteId, framesDecoded, nackCount
• RTCRemoteInboundRTPStreamStats, all required attributes from its inherited dictionaries, and also attributes localId, bytesReceived, roundTripTime
• RTCSentRTPStreamStats, with all required attributes from its inherited dictionaries, and also attributes packetsSent, bytesSent
• RTCOutboundRTPStreamStats, with all required attributes from its inherited dictionaries, and also attributes trackId, senderId, remoteId, framesEncoded, nackCount
• RTCRemoteOutboundRTPStreamStats, with all required attributes from its inherited dictionaries, and also attributes localId, remoteTimestamp
• RTCPeerConnectionStats, with attributes dataChannelsOpened, dataChannelsClosed
• RTCDataChannelStats, with attributes label, protocol, dataChannelIdentifier, state, messagesSent, bytesSent, messagesReceived, bytesReceived
• RTCMediaStreamStats, with attributes streamIdentifer, trackIds
• RTCMediaHandlerStats with attributes trackIdentifier, ended
• RTCSenderVideoTrackAttachmentStats, with all required attributes from its inherited dictionaries
• RTCSenderAudioTrackAttachmentStats, with all required attributes from its inherited dictionaries
• RTCAudioHandlerStats with attribute audioLevel
• RTCVideoHandlerStats with attributes frameWidth, frameHeight, framesPerSecond
• RTCVideoSenderStats with attribute framesSent
• RTCVideoReceiverStats with attributes framesReceived, framesDecoded, framesDropped, partialFramesLost
• RTCCodecStats, with attributes payloadType, codecType, mimeType, clockRate, channels, sdpFmtpLine
• RTCTransportStats, with attributes bytesSent, bytesReceived, rtcpTransportStatsId, selectedCandidatePairId, localCertificateId, remoteCertificateId
• RTCIceCandidatePairStats, with attributes transportId, localCandidateId, remoteCandidateId, state, priority, nominated, bytesSent, bytesReceived, totalRoundTripTime, currentRoundTripTime
• RTCIceCandidateStats, with attributes address, port, protocol, candidateType, url
• RTCCertificateStats, with attributes fingerprint, fingerprintAlgorithm, base64Certificate, issuerCertificateId

Ref :

• W3C https://w3c.github.io/mediacapture-main
• W3C Webrtc peerconnection : http://w3c.github.io/webrtc-pc
• W3C Webrtc stats : https://www.w3.org/TR/webrtc-stats/
• w3c test apis https://w3c-test.org/webrtc/
• IETF – Trickle ICE: Incremental Provisioning of Candidates for the Interactive Connectivity Establishment (ICE) Protocol draft-ietf-mmusic-trickle-ice-02
• developer mozilla – https://developer.mozilla.org/en-US/docs/Web/API/RTCRtpTransceiver

SIPp is an opensource (GNU GPL license) performance testing tool for the SIP protocol and is widely used for Quality assurabce of callflows in voip applications for UAC / UASs cenarios.

It can emulate functioing of a sip phone such as REGISTER , establishes and releases multiple calls with the INVITE and BYE methods , send other SIP requests and wait for reponses based on dafult of custom xml scenario files.

Plus factor is the dynamic display of statistics about running tests (call rate, round trip delay, and message statistics), periodic CSV statistics dumps, TCP and UDP over multiple sockets or multiplexed with retransmission management, regular expressions and variables in scenario files, and dynamically adjustable call rates.

sipp -sn uac -d 10000 -s 9876543210 127.0.0.1:5060  -l 10

It is widley used as aperformnace and load testing tool since it can test SIP equipements like SIP proxies, B2BUAs, SIP media servers, SIP/x gateways, and SIP PBXes and can also emulate thousands of user agents calling your SIP system.

More on SIPp scripts and various exmaples can be read from

https://github.com/altanai/kamailioexamples/tree/master/sipp

Installation

Pre-requisites to compile SIPp are:
– C++ Compiler
– curses or ncurses library
– For TLS support: OpenSSL >= 0.9.8
– For pcap play support: libpcap and libnet
– For SCTP support: lksctp-tools
– For distributed pauses: Gnu Scientific Libraries

sudo apt-get install dh-autoreconf ncurses-dev libssl-dev libpcap-dev libncurses5-dev libsctp-dev lksctp-tools

Either get source code from git

git clone https://github.com/SIPp/sipp.git
cd sipp
cmake . -DUSE_SSL=1 -DUSE_SCTP=1 -DUSE_PCAP=1 -DUSE_GSL=1
make

or download readymade tar , then extract and build with options like

tar -xvzf sipp-xxx.tar.gz
cd sipp
./configure --with-sctp --with-pcap --with-openssl
make

Building certs for TLS based sipp UAS server

make master dir for all certs

mkdir certs 
chmod 0700 certs
cd certs

Make CA folder, create cert and check

mkdir demoCA
cd demoCA
mkdir newcerts
echo '01' > serial
touch index.txt
openssl req -new -x509 -extensions v3_ca -keyout key.pem -out cert.pem -days 3650

Validation of the contents of certs ( optional )

openssl x509 -in cert.pem -noout -text
openssl x509 -in cert.pem -noout -dates
openssl x509 -in cert.pem -noout -purpose

Make domain folder and create the certs for the sip domain name from parent and check

cd ..
mkdir 10.10.10.10
openssl req -new -nodes -keyout key.pem -out req.pem
cd ..
openssl ca -days 730 -out 10.10.10.10/cert.pem -keyfile demoCA/key.pem -cert demoCA/cert.pem -infiles 10.10.10.10/req.pem

Verify the generated certificate for for SIP domain

openssl x509 -in 10.10.10.10/cert.pem -noout -text

Run sipp

sipp -sn uas -p 5077 -t l1 -tls_key /home/ubuntu/certs/10.10.10.10/key.pem  -tls_cert /home/ubuntu/certs/10.10.10.10/cert.pem  -i 10.10.10.10

Verify installation

Run sipp with embedded server (uas) scenario:

sipp -sn uas

On the same host, run sipp with embedded client (uac) scenario:

sipp -sn uac 127.0.0.1 -trace_msg -trace_err

output for server 

 # sipp -sn uas

------------------------------ Scenario Screen -------- [1-9]: Change Screen --

  Port   Total-time  Total-calls  Transport
  5060      32.95 s           61  UDP

0 new calls during 0.874 s period      1 ms scheduler resolution
  19 calls                               Peak was 41 calls, after 28 s
  0 Running, 63 Paused, 12 Woken up
  0 dead call msg (discarded)          
  3 open sockets                        

                             Messages  Retrans   Timeout   Unexpected-Msg

----------> INVITE             61        0         0         0 
<---------- 180                61        0                               <---------- 200                61        0         0                     ----------> ACK         E-RTD1 61        0         0         0               

----------> BYE                61        0         0         0        
   <---------- 200                61        0                            
   [   4000ms] Pause              61                            0        
 ------------------------------ Test Terminated --------------------------------

----------------------------- Statistics Screen ------- [1-9]: Change Screen --

  Start Time             | 2019-02-04    13:04:32.108663 1549265672.108663         
  Last Reset Time        | 2019-02-04    13:05:04.189720 1549265704.189720         
  Current Time           | 2019-02-04    13:05:05.065119 1549265705.065119         
-------------------------+---------------------------+--------------------------
  Counter Name           | Periodic value            | Cumulative value
-------------------------+---------------------------+--------------------------
  Elapsed Time           | 00:00:00:875000           | 00:00:32:956000          
  Call Rate              |    0.000 cps              |    1.851 cps             
-------------------------+---------------------------+--------------------------

  Incoming call created  |        0                  |       61                 

  OutGoi traceings 

———————————————– 2019-02-04 13:08:13.939148
UDP message sent (530 bytes):

INVITE sip:service@127.0.0.1:5060 SIP/2.0
 Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-25-0
 From: sipp ;tag=52422SIPpTag0025
 To: service 
 Call-ID: 25-52422@192.x.x.x
 CSeq: 1 INVITE
 Contact: sip:sipp@192.x.x.x:5061
 Max-Forwards: 70
 Subject: Performance Test
 Content-Type: application/sdp
 Content-Length:   135

v=0
o=user1 53655765 2353687637 IN IP4 192.x.x.x
s=-
c=IN IP4 192.x.x.x
t=0 0
m=audio 6004 RTP/AVP 0
a=rtpmap:0 PCMU/8000

———————————————– 2019-02-04 13:08:13.939310
UDP message received [321] bytes :

SIP/2.0 180 Ringing
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-0
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 1 INVITE
Contact: 
Content-Length: 0

———————————————– 2019-02-04 13:08:13.939905
UDP message received [486] bytes :

SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-0
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 1 INVITE
Contact: 
Content-Type: application/sdp
Content-Length:   135

v=0
o=user1 53655765 2353687637 IN IP4 192.x.x.x
s=-
c=IN IP4 192.x.x.x
t=0 0
m=audio 6000 RTP/AVP 0
a=rtpmap:0 PCMU/8000

———————————————– 2019-02-04 13:08:13.940159
UDP message sent (371 bytes):

ACK sip:service@127.0.0.1:5060 SIP/2.0
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-5
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 1 ACK
Contact: sip:sipp@192.x.x.x:5061
Max-Forwards: 70
Subject: Performance Test
Content-Length: 0

~ RTP

———————————————– 2019-02-04 13:08:13.941658
UDP message sent (371 bytes):

BYE sip:service@127.0.0.1:5060 SIP/2.0
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-7
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 2 BYE
Contact: sip:sipp@192.x.x.x:5061
Max-Forwards: 70
Subject: Performance Test
Content-Length: 0

———————————————– 2019-02-04 13:08:13.952888
UDP message received [313] bytes :

SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-7
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 2 BYE
Contact: 
Content-Length: 0

Time

---------------------------- Repartition Screen ------- [1-9]: Change Screen --

  Average Response Time Repartition 1                                           

           0 ms <= n <        10 ms :        293                                
          10 ms <= n <        20 ms :          9                                
          20 ms <= n <        30 ms :          0                                
          30 ms <= n <        40 ms :          0                                
          40 ms <= n <        50 ms :          0                                
          50 ms <= n <       100 ms :          0                                
         100 ms <= n <       150 ms :          0                                
         150 ms <= n <       200 ms :          0                                
                   n >=      200 ms :          0                                

  Average Call Length Repartition                                               

           0 ms <= n <        10 ms :          0                                
          10 ms <= n <        50 ms :          0                                
          50 ms <= n <       100 ms :          0                                
         100 ms <= n <       500 ms :          0                                
         500 ms <= n <      1000 ms :          0                                
        1000 ms <= n <      5000 ms :        262                                
        5000 ms <= n <     10000 ms :          0                                
                   n >=    10000 ms :          0                                

------------------------------ Sipp Server Mode -------------------------------

Output for client

uac.xml
 
SIPp UAC Remote
 |(1) INVITE |
 |------------------>|
 |(2) 100 (optional) |
 |<------------------| 
 |(3) 180 (optional) | 
  |<------------------| 
|(4) 200             | 
|<------------------| 
|(5) ACK             | 
|------------------>|
 |                     |
 |(6) PAUSE             |
 |                     |
 |(7) BYE             |
 |------------------>|
 |(8) 200             |
 |<------------------|

sipp -sn uac 127.0.0.1 -trace_msg -trace_err
Resolving remote host ‘127.0.0.1’… Done.
—————————— Scenario Screen ——– [1-9]: Change Screen —
Call-rate(length) Port Total-time Total-calls Remote-host
10.0(0 ms)/1.000s 5061 17.32 s 98 127.0.0.1:5060(UDP)

3 new calls during 0.286 s period 1 ms scheduler resolution
0 calls (limit 30) Peak was 25 calls, after 10 s
0 Running, 101 Paused, 7 Woken up
0 dead call msg (discarded) 0 out-of-call msg (discarded)
3 open sockets

                             Messages  Retrans   Timeout   Unexpected-Msg
  INVITE ---------->         98        0         0                  
     100 <----------         0         0         0         0        
     180 <----------         98        0         0         0        
     183 <----------         0         0         0         0        
     200          98        0                            
   Pause [      0ms]         98                            0        
     BYE ---------->         98        0         0                  
     200 <----------         98        0         0         0        

—————————— Test Terminated ——————————–

----------------------------- Statistics Screen ------- [1-9]: Change Screen --

  Start Time             | 2019-02-04    13:08:03.908208 1549265883.908208         
  Last Reset Time        | 2019-02-04    13:08:20.954289 1549265900.954289         
  Current Time           | 2019-02-04    13:08:21.241152 1549265901.241152         

-------------------------+---------------------------+--------------------------
  Counter Name           | Periodic value            | Cumulative value

-------------------------+---------------------------+--------------------------
  Elapsed Time           | 00:00:00:286000           | 00:00:17:332000          

  Call Rate  

Tracings

———————————————– 2019-02-04 13:08:13.934840
UDP message received [527] bytes :

INVITE sip:service@127.0.0.1:5060 SIP/2.0
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-0
From: sipp ;tag=52422SIPpTag001
To: service 
Call-ID: 1-52422@192.x.x.x
CSeq: 1 INVITE
Contact: sip:sipp@192.x.x.x:5061
Max-Forwards: 70
Subject: Performance Test
Content-Type: application/sdp
Content-Length:   135

v=0
o=user1 53655765 2353687637 IN IP4 192.x.x.x
s=-
c=IN IP4 192.x.x.x
t=0 0
m=audio 6004 RTP/AVP 0
a=rtpmap:0 PCMU/8000

———————————————– 2019-02-04 13:08:13.936616
UDP message sent (321 bytes):

SIP/2.0 180 Ringing
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-0
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 1 INVITE
Contact: 
Content-Length: 0

———————————————– 2019-02-04 13:08:13.937003
UDP message sent (486 bytes):

SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-0
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 1 INVITE
Contact: 
Content-Type: application/sdp
Content-Length:   135

v=0
o=user1 53655765 2353687637 IN IP4 192.x.x.x
s=-
c=IN IP4 192.x.x.x
t=0 0
m=audio 6000 RTP/AVP 0
a=rtpmap:0 PCMU/8000

———————————————– 2019-02-04 13:08:13.948679
UDP message received [371] bytes :

ACK sip:service@127.0.0.1:5060 SIP/2.0
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-5
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 1 ACK
Contact: sip:sipp@192.x.x.x:5061
Max-Forwards: 70
Subject: Performance Test
Content-Length: 0

~ RTP

———————————————– 2019-02-04 13:08:13.949168
UDP message received [371] bytes :

BYE sip:service@127.0.0.1:5060 SIP/2.0
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-7
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 2 BYE
Contact: sip:sipp@192.x.x.x:5061
Max-Forwards: 70
Subject: Performance Test
Content-Length: 0

———————————————– 2019-02-04 13:08:13.949245
UDP message sent (313 bytes):

SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.x.x.x:5061;branch=z9hG4bK-52422-1-7
From: sipp ;tag=52422SIPpTag001
To: service ;tag=52416SIPpTag011
Call-ID: 1-52422@192.x.x.x
CSeq: 2 BYE
Contact: 
Content-Length: 0

time

---------------------------- Repartition Screen ------- [1-9]: Change Screen --

  Average Response Time Repartition 1                                           

           0 ms <= n <        10 ms :        657                                
          10 ms <= n <        20 ms :         20                                
          20 ms <= n <        30 ms :          0                                
          30 ms <= n <        40 ms :          0                                
          40 ms <= n <        50 ms :          0                                
          50 ms <= n <       100 ms :          0                                
         100 ms <= n <       150 ms :          0                                
         150 ms <= n <       200 ms :          0                                
                   n >=      200 ms :          0                                

  Average Call Length Repartition                                               

           0 ms <= n <        10 ms :        649                                
          10 ms <= n <        50 ms :         28                                
          50 ms <= n <       100 ms :          0                                
         100 ms <= n <       500 ms :          0                                
         500 ms <= n <      1000 ms :          0                                
        1000 ms <= n <      5000 ms :          0                                
        5000 ms <= n <     10000 ms :          0                                
                   n >=    10000 ms :          0                                

------ [+|-|*|/]: Adjust rate ---- [q]: Soft exit ---- [p]: Pause traffic -----

Last Error: Overload warning: the major watchdog timer 3000ms has been t…

UAC with Media

SIPp UAC            Remote
    |(1) INVITE         |
    |------------------>|
    |(2) 100 (optional) |
    |<------------------|
    |(3) 180 (optional) |
    |<------------------|
    |(4) 200            |
    |<------------------|
    |(5) ACK            |
    |------------------>|
    |                   |
    |(6) RTP send (8s)  |
    |==================>|
    |                   |
    |(7) RFC2833 DIGIT 1|
    |==================>|
    |                   |
    |(8) BYE            |
    |------------------>|
    |(9) 200            |
    |<------------------|

sipp Usage:

sipp remote_host[:remote_port] [options]

Run SIPp with embedded server (uas) scenario: ./sipp -sn uas On the same host, run SIPp with embedded client (uac) scenario: ./sipp -sn uac 127.0.0.1

Scenario file options:

• -sd : Dumps a default scenario (embedded in the SIPp executable)
• -sf : Loads an alternate XML scenario file. To learn more about XML scenario syntax, use the -sd option to dump embedded scenarios. They contain all the necessary help.
• -oocsf : Load out-of-call scenario.
• -oocsn : Load out-of-call scenario.
• -sn : Use a default scenario (embedded in the SIPp executable). If this option is omitted, the Standard SipStone UAC scenario is loaded. Available values in this version: 
  • ‘uac’ : Standard SipStone UAC (default).
  • ‘uas’ : Simple UAS responder.
  • ‘regexp’ : Standard SipStone UAC – with regexp and variables.
  • ‘branchc’ : Branching and conditional branching in scenarios – client.
  • ‘branchs’ : Branching and conditional branching in scenarios – server.
  Default 3pcc scenarios (see -3pcc option):
  • ‘3pcc-C-A’ : Controller A side (must be started after all other 3pcc scenarios)
  • ‘3pcc-C-B’ : Controller B side.
  • ‘3pcc-A’ : A side.
  • ‘3pcc-B’ : B side.

IP, port and protocol options

• -t : Set the transport mode:
  • u1: UDP with one socket (default),
  • un: UDP with one socket per call,
  • ui: UDP with one socket per IP address. The IP addresses must be defined in the injection file.
  • t1: TCP with one socket,
  • tn: TCP with one socket per call,
  • l1: TLS with one socket,
  • ln: TLS with one socket per call,
  • c1: u1 + compression (only if compression plugin loaded),
  • cn: un + compression (only if compression plugin loaded). This plugin is not provided with SIPp.
• -i : Set the local IP address for ‘Contact:’,’Via:’, and ‘From:’ headers. Default is primary host IP address.
• -p : Set the local port number. Default is a random free port chosen by the system 
• -bind_local : Bind socket to local IP address, i.e. the local IP address is used as the source IP address. If SIPp runs in server mode it will only listen on the local IP address instead of all IP addresses.
• -ci : Set the local control IP address
• -cp : Set the local control port number. Default is 8888.
• -max_socket : Set the max number of sockets to open simultaneously. This option is significant if you use one socket per call. Once this limit is reached, traffic is distributed over the sockets already opened. Default value is 50000
• -max_reconnect : Set the the maximum number of reconnection.
• -reconnect_close : Should calls be closed on reconnect?
• -reconnect_sleep : How long (in milliseconds) to sleep between the close and reconnect?
• -rsa : Set the remote sending address to host:port for sending the messages.
• -tls_cert : Set the name for TLS Certificate file. Default is ‘cacert.pem
• -tls_key : Set the name for TLS Private Key file. Default is ‘cakey.pem’
• -tls_ca : Set the name for TLS CA file. If not specified, X509 verification is not activated.
• -tls_crl : Set the name for Certificate Revocation List file. If not specified, X509 CRL is not activated.
• -tls_version : Set the TLS protocol version to use (1.0, 1.1, 1.2) — default is autonegotiate

SIPp overall behavior options:

• -v : Display version and copyright information.
• -bg : Launch SIPp in background mode.
• -nostdin : Disable stdin.
• -plugin : Load a plugin.
• -sleep : How long to sleep for at startup. Default unit is seconds.
• -skip_rlimit : Do not perform rlimit tuning of file descriptor limits. Default: false.
• -buff_size : Set the send and receive buffer size.
• -sendbuffer_warn : Produce warnings instead of errors on SendBuffer failures.
• -lost : Set the number of packets to lose by default (scenario specifications override this value).
• -key : keyword value Set the generic parameter named “keyword” to “value”.
• -set : variable value Set the global variable parameter named “variable” to “value”.
• -tdmmap : Generate and handle a table of TDM circuits. A circuit must be available for the call to be placed. Format: -tdmmap {0-3}{99}{5-8}{1-31}
• -dynamicStart : variable value Set the start offset of dynamic_id variable
• -dynamicMax : variable value Set the maximum of dynamic_id variable 
• -dynamicStep : variable value Set the increment of dynamic_id variable

Call behavior options:

• -aa : Enable automatic 200 OK answer for INFO, NOTIFY, OPTIONS and UPDATE.
• -base_cseq : Start value of [cseq] for each call.
• -cid_str : Call ID string (default %u-%p@%s). %u=call_number, %s=ip_address, %p=process_number, %%=% (in any order).
• -d : Controls the length of calls. More precisely, this controls the duration of ‘pause’ instructions in the scenario, if they do not have a ‘milliseconds’ section. Default value is 0 and default unit is milliseconds.
• -deadcall_wait : How long the Call-ID and final status of calls should be kept to improve message and error logs (default unit is ms).
• -auth_uri : Force the value of the URI for authentication. By default, the URI is composed of remote_ip:remote_port.
• -au : Set authorization username for authentication challenges. Default is taken from -s argument
• -ap : Set the password for authentication challenges. Default is ‘password’
• -s : Set the username part of the request URI. Default is ‘service’.
• -default_behaviors: Set the default behaviors that SIPp will use. Possible values are:
  • all Use all default behaviors
  • none Use no default behaviors
  • bye Send byes for aborted calls
  • abortunexp Abort calls on unexpected messages
  • pingreply Reply to ping requests If a behavior is prefaced with a -, then it is turned off. Example: all,-bye
• -nd : No Default. Disable all default behavior of SIPp which are the following:
• On UDP retransmission timeout, abort the call by sending a BYE or a CANCEL
• On receive timeout with no ontimeout attribute, abort the call by sending a BYE or a CANCEL
• On unexpected BYE send a 200 OK and close the call
• On unexpected CANCEL send a 200 OK and close the call
• On unexpected PING send a 200 OK and continue the call
• On any other unexpected message, abort the call by sending a BYE or a CANCEL
• -pause_msg_ign : Ignore the messages received during a pause defined in the scenario 
• -callid_slash_ign: Don’t treat a triple-slash in Call-IDs as indicating an extra SIPp prefix.

Injection file options:

• -inf : Inject values from an external CSV file during calls into the scenarios. First line of this file say whether the data is to be read in sequence (SEQUENTIAL), random (RANDOM), or user (USER) order. Each line corresponds to one call and has one or more ‘;’ delimited data fields. Those fields can be referred as [field0], [field1], … in the xml scenario file. Several CSV files can be used simultaneously (syntax: -inf f1.csv -inf f2.csv …)
• -infindex : file field Create an index of file using field. For example -inf ../path/to/users.csv -infindex users.csv 0 creates an index on the first key.
• -ip_field : Set which field from the injection file contains the IP address from which the client will send its messages. If this option is omitted and the ‘-t ui’ option is present, then field 0 is assumed. Use this option together with ‘-t ui’

RTP behaviour options:

• -mi : Set the local media IP address (default: local primary host IP address)
• -rtp_echo : Enable RTP echo. RTP/UDP packets received on port defined by -mp are echoed to their sender. RTP/UDP packets coming on this port + 2 are also echoed to their sender (used for sound and video echo).
• -mb : Set the RTP echo buffer size (default: 2048).
• -mp : Set the local RTP echo port number. Default is 6000.
• -rtp_payload : RTP default payload type.
• -rtp_threadtasks : RTP number of playback tasks per thread.
• -rtp_buffsize : Set the rtp socket send/receive buffer size.

Call rate options:

• -r : Set the call rate (in calls per seconds). This value can bechanged during test by pressing ‘+’, ‘_’, ‘*’ or ‘/’. Default is 10.
  • pressing ‘+’ key to increase call rate by 1 * rate_scale,
  • pressing ‘-‘ key to decrease call rate by 1 * rate_scale,
  • pressing ‘*’ key to increase call rate by 10 * rate_scale,
  • pressing ‘/’ key to decrease call rate by 10 * rate_scale.
• -rp : Specify the rate period for the call rate. Default is 1 second and default unit is milliseconds. This allows you to have n calls every m milliseconds(by using -r n -rp m). Example: -r 7 -rp 2000 ==> 7 calls every 2 seconds. -r 10 -rp 5s => 10 calls every 5 seconds.
• -rate_scale : Control the units for the ‘+’, ‘-‘, ‘*’, and ‘/’ keys.
• -rate_increase : Specify the rate increase every -rate_interval units (default is seconds). This allows you to increase the load for each independent logging period. Example: -rate_increase 10 -rate_interval 10s ==> increase calls by 10 every 10 seconds.
• -rate_max : 

If -rate_increase is set, then quit after the rate reaches this value. Example: -rate_increase 10 -rate_max 100 ==> increase calls by 10 until 100 cps is hit.

• -rate_interval : Set the interval by which the call rate is increased. Defaults to the value of -fd.
• -no_rate_quit : If -rate_increase is set, do not quit after the rate reaches -rate_max.
• -l :  Set the maximum number of simultaneous calls. Once this limit is reached, traffic is decreased until the number of open calls goes down. Default: (3 * call_duration (s) * rate).

• -m : Stop the test and exit when ‘calls’ calls are processed
• -users : Instead of starting calls at a fixed rate, begin ‘users’ calls at startup, and keep the number of calls constant.

Retransmission and timeout options:

• -recv_timeout : Global receive timeout. Default unit is milliseconds. If the expected message is not received, the call times out and is aborted.
• -send_timeout : Global send timeout. Default unit is milliseconds. If a message is not sent (due to congestion), the call times out and is aborted.
• -timeout : Global timeout. Default unit is seconds. If this option is set, SIPp quits after nb units (-timeout 20s quits after 20 seconds).
• -timeout_error : SIPp fails if the global timeout is reached is set (-timeout option required).
• -max_retrans : Maximum number of UDP retransmissions before call ends on timeout. Default is 5 for INVITE transactions and 7 for others.
• -max_invite_retrans: Maximum number of UDP retransmissions for invite transactions before call ends on timeout.
• -max_non_invite_retrans: Maximum number of UDP retransmissions for non-invite transactions before call ends on timeout.
• -nr : Disable retransmission in UDP mode.
• -rtcheck : Select the retransmission detection method: full (default) or loose.
• -T2 : Global T2-timer in milli seconds

Third-party call control options:

• -3pcc : Launch the tool in 3pcc mode (“Third Party call control”). The passed IP address depends on the 3PCC role.
  • When the first twin command is ‘sendCmd’ then this is the address of the remote twin socket. SIPp will try to connect to this address:port to send the twin command (This instance must be started after all other 3PCC scenarios). Example: 3PCC-C-A scenario.
  • When the first twin command is ‘recvCmd’ then this is the address of the local twin socket. SIPp will open this address:port to listen for twin command. Example: 3PCC-C-B scenario.
• -master : 3pcc extended mode: indicates the master number
• -slave : 3pcc extended mode: indicates the slave number
• -slave_cfg : 3pcc extended mode: indicates the file where the master and slave addresses are stored

Performance and watchdog options:

• -timer_resol
  Set the timer resolution. Default unit is milliseconds. This option has an impact on timers precision.Small values allow more precise scheduling but impacts CPU usage.If the compression is on, the value is set to 50ms. The default value is 10ms.
• -max_recv_loops Set the maximum number of messages received read per cycle. Increase this value for high traffic level. The default value is 1000.
• -max_sched_loops Set the maximum number of calls run per event loop. Increase this value for high traffic level. The default value is 1000.
• -watchdog_interval : Set gap between watchdog timer firings. Default is 400.
• -watchdog_reset : If the watchdog timer has not fired in more than this time period, then reset the max triggers counters. Default is 10 minutes.
• -watchdog_minor_threshold: If it has been longer than this period between watchdog executions count a minor trip. Default is 500.
• -watchdog_major_threshold: If it has been longer than this period between watchdog executions count a major trip. Default is 3000.
• -watchdog_major_maxtriggers : How many times the major watchdog timer can be tripped before the test is terminated. Default is 10.
• -watchdog_minor_maxtriggers: How many times the minor watchdog timer can be tripped before the test is terminated. Default is 120.

Tracing, logging and statistics options:

• -f : Set the statistics report frequency on screen. Default is 1 and default unit is seconds.
• -trace_stat : Dumps all statistics in <scenario_name>_.csv file. Use the ‘-h stat’ option for a detailed description of the statistics file content.
• -stat_delimiter : Set the delimiter for the statistics file
• -stf : Set the file name to use to dump statistics
• -fd : Set the statistics dump log report frequency. Default is 60 and default unit is seconds.
• -periodic_rtd : Reset response time partition counters each logging interval.
• -trace_msg : Displays sent and received SIP messages in __messages.log
• -message_file : Set the name of the message log file.
• -message_overwrite: Overwrite the message log file (default true).
• -trace_shortmsg : Displays sent and received SIP messages as CSV in <scenario file name>__shortmessages.log
• -shortmessage_file: Set the name of the short message log file.
• -shortmessage_overwrite: Overwrite the short message log file (default true).
• -trace_counts : Dumps individual message counts in a CSV file.
• -trace_err : Trace all unexpected messages in __errors.log.
• -error_file : Set the name of the error log file.
• -error_overwrite : Overwrite the error log file (default true).
• -trace_error_codes: Dumps the SIP response codes of unexpected messages to <scenario file name>__error_codes.log.
• -trace_calldebug : Dumps debugging information about aborted calls to <scenario_name>__calldebug.log file.
• -calldebug_file : Set the name of the call debug file.
• -calldebug_overwrite: Overwrite the call debug file (default true).
• -trace_screen : Dump statistic screens in the <scenario_name>__screens.log file when quitting SIPp. Useful to get a final status report in background mode (-bg option).
• -screen_file : Set the name of the screen file.
• -screen_overwrite: Overwrite the screen file (default true).
• -trace_rtt : Allow tracing of all response times in __rtt.csv.
• -rtt_freq : freq is mandatory. Dump response times every freq calls in the log file defined by -trace_rtt. Default value is 200.
• -trace_logs : Allow tracing of actions in __logs.log.
• -log_file : Set the name of the log actions log file.
• -log_overwrite : Overwrite the log actions log file (default true).
• -ringbuffer_files: How many error, message, shortmessage and calldebug files should be kept after rotation?
• -ringbuffer_size : How large should error, message, shortmessage and calldebug files be before they get rotated?
• -max_log_size : What is the limit for error, message, shortmessage and calldebug file sizes.

Signal handling:

SIPp can be controlled using POSIX signals. The following signals are handled: USR1: Similar to pressing the ‘q’ key. It triggers a soft exit of SIPp. No more new calls are placed and all ongoing calls are finished before SIPp exits. Example: kill -SIGUSR1 732 USR2: Triggers a dump of all statistics screens in <scenario_name>__screens.log file. Especially useful in background mode to know what the current status is. Example: kill -SIGUSR2 732

Exit codes:

Upon exit (on fatal error or when the number of asked calls (-m option) is reached, SIPp exits with one of the following exit code: 0: All calls were successful 1: At least one call failed 97: Exit on internal command. Calls may have been processed 99: Normal exit without calls processed -1: Fatal error -2: Fatal error binding a socket

Debugging

Issue1  The commonName field needed to be supplied and was missing 

Solution Given the common name while generating the certs

Issue2 If cmake error appears such as “command not found: cmake” then 

solutionsudo apt-get install build-essential cmake

References :

• https://media.readthedocs.org/pdf/sipp-wip/latest/sipp-wip.pdf
• https://github.com/SIPp/sipp.git