Comet Labs IPTEL-S Instrukcja Użytkownika Strona 1

Introduction to SIP and VoIP8/31/2005 Copyright - Ahlgren 2005 1AhlTekDavid AhlgrenTechnology and Business Development

Related IETF Working Groups 8/31/2005 Copyright - Ahlgren 2005 10AhlTekSIMPLE SIP for Instant Messaging and Presence Language Extensions MMUSIC Multip

A Remarkably Fast Timeline ! 8/31/2005 Copyright - Ahlgren 2005 11AhlTek1996 Academic R&D First technology concept drafts1999 Skunk works RFC 2543

SIP - A New Generation of Communication Services8/31/2005 Copyright - Ahlgren 2005 12AhlTek SIP Extends the ITEF spirit of open standards Disruptive

What Did SIP Inherit? 8/31/2005 Copyright - Ahlgren 2005 13AhlTek URLs: general references, recursive,  Can be embedded in web pages SIP: Dave@dave

SIP Design Choices8/31/2005 Copyright - Ahlgren 2005 14AhlTek Distributed architecture: Smart end points and components  Separate signaling:  Cont

SIP is a Distributed Architecture8/31/2005 Copyright - Ahlgren 2005 15AhlTekPeer to PeerProxy ServerUser Agent ServerUser Agent ClientINVITE: msbINVIT

SIP is Not 8/31/2005 Copyright - Ahlgren 2005 16AhlTek SIP is not a turnkey application - It is not Instant messaging, VoIP, or Video on demand. 

SIP Not a Transport8/31/2005 Copyright - Ahlgren 2005 17AhlTek Independent of the packet layer Provides its own reliability mechanism. Does not req

SIP Needs Other Protocols8/31/2005 Copyright - Ahlgren 2005 18AhlTek SDP - Session Description Protocol Describes the media content of the session

8/31/2005 Copyright - Ahlgren 2005 19AhlTekSession Description Protocol (SDP) Conveys information for a multimedia session Media to use (codec, samp

Agenda8/31/2005 Copyright - Ahlgren 2005 2AhlTek Hello, Schedule & Hand outs SIP Overview, Status & Standards SIP Design Concepts and Archi

8/31/2005 Copyright - Ahlgren 2005 20AhlTekReal Time Transport Protocol (RTP) Designed to be scalable, flexible Media content type – Voice Video etc

SIP Application Server8/31/2005 Copyright - Ahlgren 2005 21AhlTekAlcatel

SIP Practical Issues8/31/2005 Copyright - Ahlgren 2005 22AhlTek SIP’s Prime competitor is H.323  It is closed protocol providing signaling and media

SIP Functionality8/31/2005 Copyright - Ahlgren 2005 23AhlTekUser location: Determination of the end system to be used for communication; Translate us

8/31/2005 Copyright - Ahlgren 2005 24AhlTekMajor Components of the SIP EnvironmentUser AgentsEnd-users devices or gateway to other networks- Cell phon

SIP Message8/31/2005 Copyright - Ahlgren 2005 25AhlTekINVITE: sip:[email protected] m SIP/2.0 Via: SIP/2.0/UDP userA.yahoo.comFrom: userA. <sip:userA@y

Message Types8/31/2005 Copyright - Ahlgren 2005 26AhlTekINVITE Initiates a call, changes call parameters (re-INVITE).ACK Confirms a final response b

Status Codes 8/31/2005 Copyright - Ahlgren 2005 27AhlTek Borrowed from HTTP.  x80 and higher codes avoid conflicts with future HTTP response codes

Basic Message Format 8/31/2005 Copyright - Ahlgren 2005 28AhlTekSIP Control messages are human readable clear text START LINE Request or Status resp

Message - START LINE 8/31/2005 Copyright - Ahlgren 2005 29AhlTek Each SIP message begins with a Start Line Conveys the message type and protocol ver

What is SIP ?-8/31/2005 Copyright - Ahlgren 2005 3AhlTek A power full new communication method IP network based Enables new forms of communications

Message - HEADERS Fields8/31/2005 Copyright - Ahlgren 2005 30AhlTek Convey message attributes and modify message meaning.  Similar in syntax and sem

Message - BODY (CONTENT) 8/31/2005 Copyright - Ahlgren 2005 31AhlTek Describes the session to be initiated, audio and video codec types, sampling rat

Message - SAMPLE 8/31/2005 Copyright - Ahlgren 2005 32AhlTekRequest Message line DescriptionINVITE sip:[email protected] m SIP/2.0 Method type, request U

SIP Call Flow - Direct8/31/2005 Copyright - Ahlgren 2005 33AhlTek The call flow for SIP sessions depends upon whether the SIP session is established

8/31/2005 Copyright - Ahlgren 2005 34AhlTekSIP Call Flow with Proxy Server The proxy server is a communication midpoint, functioning as both a user s

SIP Questions Now? 8/31/2005 Copyright - Ahlgren 2005 35AhlTek Control vs. Transport Extensions to other protocols User Agents, proxies, registrar

VoIP – Reinventing the Wheel 8/31/2005 Copyright - Ahlgren 2005 36AhlTek Voice over IP – Voice over broadband networks Private networks Public inte

VoIP Advantages8/31/2005 Copyright - Ahlgren 2005 37AhlTek Lower cost Increased functionality More services, more user control Calls routed to whe

What services do you get?8/31/2005 Copyright - Ahlgren 2005 38AhlTek Standard Features without extra cost Caller ID Call waiting  Call transfer 

Making the VoIP Connection8/31/2005 Copyright - Ahlgren 2005 39AhlTek ATA – Analog Telephone Adaptor The most common VoIP connection is via an ATA.

How can SIP be used?8/31/2005 Copyright - Ahlgren 2005 4AhlTek IP Telephony – Voice & Video Instant Messaging Music and video on demand Intera

Product Examples8/31/2005 Copyright - Ahlgren 2005 40AhlTekATAAdaptor$60X LiteSoft PhoneFreeCiscoIP Phone$900

And VoIP can be Invisible 8/31/2005 Copyright - Ahlgren 2005 41AhlTek Computers are embedded everywhere “VoIP” technology will appear in Internet a

VoIP Architectures8/31/2005 Copyright - Ahlgren 2005 42AhlTekFeatures/Functions SIP H.323 Megaco/MGCPMultiple domains x ? –Third-party control x

8/31/2005 Copyright - Ahlgren 2005 43AhlTekVoIP Codecs –Bandwidth RequirementsCodec Algorithm Kb/s* MOS**G.711 PCM 64 4.1 G.726 ADPCM 32 3.85 G.72

NAT Transversal 8/31/2005 Copyright - Ahlgren 2005 44AhlTek SIP end points behind Firewalls/NAT do not have public IP address There are at lease 4 t

8/31/2005 Copyright - Ahlgren 2005 45AhlTekVoIP Network Performance Considerations Latency – Delay of packet delivery 250 ms round trip max, 150 ms

SIP and QoS Control8/31/2005 Copyright - Ahlgren 2005 46AhlTek SIP does not provide QoS support. SIP can requests QoS via the notion of precondition

QoS Protocols8/31/2005 Copyright - Ahlgren 2005 47AhlTek RSVP – Resource Reservation Protocol Request priority service from each router on the path

Questions – VoIP8/31/2005 Copyright - Ahlgren 2005 48AhlTek Applying VoIP Advantages Services Network requirement QoS

Attachments8/31/2005 Copyright - Ahlgren 2005 49AhlTek SIP and VoIP Reference and Glossary

SIP Based Products8/31/2005 Copyright - Ahlgren 2005 5AhlTek SIP VoIP Phones Pingtel, Cisco, Polycom SIP Analog Phone Adaptors - ATA ATT, Vonage,

Thank YouPlease contact me for a copy of these slides8/31/2005 Copyright - Ahlgren 2005 50AhlTekDavid Ahlgren760 846 [email protected]

Who is using SIP?8/31/2005 Copyright - Ahlgren 2005 6AhlTek ATT Call Advantage, VoIP, US & Canada, $30/mo Vonage VoIP, US & Canada, $25/mo,

Who Invented SIP?8/31/2005 Copyright - Ahlgren 2005 7AhlTek Authors:  Henning. Schulzrinne, Columbia U., M. Handley, ACIRI, E. Schooler, Cal Tech, J

SIP Standardization Efforts8/31/2005 Copyright - Ahlgren 2005 8AhlTek One of the most active working groups in the IETF Located in “transport” area,

8/31/2005 Copyright - Ahlgren 2005 9AhlTekSupported by Multiple Standards GroupsIETF Internet Engineering Task ForceIETF PINT PSTN Internet Interface