Server-side WebRTC Infrastructure

Company Confidential: © COPYRIGHT 2015 DIALOGIC INC. ALL RIGHTS RESERVED.

Server-side WebRTC Infrastructure

Chad Hart

Director, Product Marketing

WebRTC Japan Conference5 Feb 2015

COMPANY CONFIDENTIAL: © COPYRIGHT 2015 DIALOGIC INC. ALL RIGHTS RESERVED. 2

About Me

Sr. Director, Product Marketing Blogger & Chief Editor


Dialogic Overview

ExperiencedOver 25 years connecting and adding value to Enterprise and Service Provider Networks

Global presenceUS HQ (New Jersey) / 20+ Regional offices

StrengthsProducts are widely deployed

Impacting 4+ billion mobile subscribers

15+ Billion VoIP minutes / month

Excellent Support

Customers include 48 of top 50 mobile carriers and 80% of the Fortune 1000

Approximately 200 patents issued or pending

Key Product & ServicesRich Media Processing

PowerMedia: Media Server / IMS MRF / SR140

Class 4 Softswitch / IMS MGCF and VoIP Gateways

Mobile Signaling / Diameter Signaling Controllers


WebRTC Server Considerations

SignalingNAT

TraversalMedia Gateway


WebRTC is not 100% Peer-to-Peer

Server

client client

media


WebRTC Signaling Servers Relay SDP between Clients

Real WebRTC Session Description

Protocol (SDP) example (partial)

Source: webrtchacks.com/sdp-anatomy


Signaling Considerations Outside of WebRTC

User authenticationSecurity & access

controlsMobile push services

FederationThe rest of your

application


The NAT Traversal Problem

Image source: webrtcHacks - https://webrtchacks.com/stun-helps-webrtc-traverse-nats/


How does WebRTC Traverse Firewalls & NATs?

media

FW & NAT

FW & NAT

client client10.10.1.1 192.168.10.1200.2.20.2

2100.1.10.1

1

Signaling Server


Interactive Connectivity Establishment (ICE)

A protocol for establishing a peer-to-peer media connection between peers behind NAT and firewall devices.

ICE requires 2 kinds of servers: 1. STUN 2. TURN


STUN – What is my external IP address?

Signaling Server

media

client10.10.1.1 200.2.20.2

2

What is my external IP address?

FW & NAT

STUN Server

Your IP address is 200.2.20.22


TURN will relay your media

media

client

Signaling Server

TURN Server

STUN Server

client


Comparing STUN vs. TURN

STUN Server TURN Server

What it does?Returns an external IP

addressRelays media

When is it needed? Almost always Rarely

How much does it cost to operate?

Inexpensive Expensive

Does it affect voice quality?

No Possible


Peer-to-Peer vs. Peer-to-Server

Server

client client

media

Peer-to-Peer

client client

Media Server

Signaling Server

Peer-to-Server


Many Reasons for a Media Server

Conferencing InterworkingTranscoding

Stream processingRecording Person-to-machine


Who do You Care About More?


Bandwidth is not Always Ubiquitous or Free

Client-side Server-side


CPU & Processing Power is Expensive

Client view Provider View


Multi-PARTY! Video Conferencing


Easy & Cheap Approach to Multi-party: Mesh

20

Full Mesh

Works for a few parties

No server cost

Lowest latency


Mesh does not Scale for Many Video Conferees

21

Full Mesh

Clients get overloadedEncode costs more than decode

Limited uplink bandwidth

Inconsistent performance across participants


Traditional Telephony Approach: MCU

22

Multipoint Control Unit (MCU)Good at manipulating all media

Transcoding

Transizing

Transrating

Interworking

Server-side CPU intensive

Client can request different conference mixes

Usually client friendly

Downsizing & mixing can reduce bandwidth

Fewer client streams to process

MCU


Traditional MCU Resource Usage

23

Worst-case process:1. Each stream decoded

at the MCU

2. MCU mixes each conferee

3. MCU encodes individual mix for each conferee

MCU

1

1 22

3

3

445

5

6

6

Ingress streams 6

Egress streams 6

MCU decodes 6

MCU encodes 6


Efficient MCU Resource Usage

24

Efficient process:1. Each stream decoded

at the MCU

2. MCU mixes each conferee

3. MCU shares same encoder for all conferees

MCU

12

3

45

6

Ingress streams 6

Egress streams 6

MCU decodes 6

MCU encodes 1

1


Resource Efficient MCU with Encoder Sharing

30%-50% reduction in compute resources

0%

20%

40%

60%

80%

100%

1 2 3 4 5 6 7 8 9 10 11 15 17 20

Syst

em

CP

U U

tiliz

atio

n

Conferees

Encoder sharing vs. multi-encode

Traditional MCU Dialogic Evolved MCU


Newer Approach: SFU

26

SFU

Selective Forwarding Unit (SFU) routing

Clients send one & receive many

Client can instruct SFU which streams to send

High throughput

Can be lots of downlink bandwidth

Low latency


Newer Approach: SFU

27

SFU

Selective Forwarding Unit (SFU) routing

Clients send one & receive many

Client can instruct SFU which streams to send

High throughput

Can be lots of downlink bandwidth

Low latency


New WebRTC Approach: Simulcast

28

SFU

High bitrate

Low bitrate

Selective Forwarding Unit (SFU) with Simulcast

Clients send multiple streams to SFU

one high-bit rate

one or more lower-bit

Client directs SFU which streams to receive

Reduces bandwidth vs. SFU

Simulcast in WebRTC coming


A look at Google Hangouts with Simulcast

http://webrtchacks.com/hangout-analysis-philipp-hancke/

http://webrtchacks.com/hangout-analysis-philipp-hancke/


Future Approach with VP9 – SVC?

30

SFU

MediumHigh LowLayered bitrates:

Selective Forwarding Unit (SFU) with Scalable Video Coding (SVC)

Clients send layered stream to SFU

Layers have varying bitrates –time, size, quality

SFU directs who gets what

Coming to WebRTC eventually


Multi-party video summary comparison

http://networkfuel.dialogic.com/webrtc-whitepaper

http://networkfuel.dialogic.com/webrtc-whitepaper


Many Reasons for a Media Server

Conferencing InterworkingTranscoding

Stream processing Person-to-machineRecording


Case Study: Video Recording Service

Application highlightsRecord live events – E.g. Kids soccer gameShare event recording with family/friends – Multi-party stream

Many Recording Formats.3GP.mp4.wav

Many CodecsG.711, Opus, AMR-NB and AMR-WB (voice)VP8, H.264 (video)

Message StorageLocal storageRemote message deposit via MSRP

HTTP/MSRP

REST (HTTP)

Application Server

Media Server

Message Storage

RTP (media)

Solution HighlightsSoftware-based Media Server

Virtualized (VM) and COTS deployment

High Availability and Geographical Redundancy

Scalability via Media Resource Broker

Architected to support 3.5M Subscriber Network

Recording

Remote Message Deposit

Key Functions

Transcoding

WebRTC Signaling

WAN


Core WebRTC Gateway & Peripheral Functions

HTTP-to-SIP(H2S)

Media GW

Transcoder

Web SIP

SBCSTUN Server

TURN Server

API Gateway

Regulates API calls

Provides media anchoring for NAT Traversal

Tells a client what its IP address is

Converts non-standard web

signaling to SIP

Web SDK/ Widget

Mobile SDK/ Widget

Kit for adding Calls to

webpage

Kit for adding Calls to native applications

Converts one codec to another, trans-rates/sizing

Encryption & transport interworking

SIP interworking, media binding, and

security


WebRTC Gateways Come in Many Packages

API Gateway H2S

Media GW SBC

Transcoder

STUN Server

TURN Server

API Gateway H2S

Media GW SBC

Transcoder

STUN Server

TURN Server

H2S

Media GW

Transcoder

SBC

API Gateway

STUN Server

TURN Server

API Gateway H2S

SBCMedia GW

Transcoder

STUN Server

TURN Server

API Gateway H2S

SBCMedia GW

Transcoder

STUN Server

TURN Server

API Gateway H2S

Media GW SBC

Transcoder

STUN Server

TURN Server


Example: Large, Web-Centric Network Architecture

Web server

SIP/IMS Network

SIP

Web Media

GatewayFirewall

AP

I Man

ager

API Calls

H2S Server

Identity Server

App Server

App Server

WSS server

STUN/ TURN

Internal REST APIs

WebRTCBrowser


WebRTC Servers Summary

Server Type Why/when you need it

Signaling Server Required to setup a WebRTC session

STUN Server Provides NAT traversal as part of ICE protocol

TURN ServerRelays media when direct connection cannot be established

Media ServerProvides conferencing, recording, media interworking, transcoding, stream processing

WebRTC GatewayInterworks signaling and media with existing VoIP networks


Questions?

Server-side WebRTC Infrastructure

Technology

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