Examining SIP Based EndpointsExamining SIP Based Endpoints

Jon YoungJon YoungDirector, Softswitch TechnologyDirector, Softswitch Technology

InterInter--Tel, Inc.Tel, Inc.

SIP Endpoints

• Current state• Types of endpoints• Endpoint composition• Extensions of SIP and other protocols on

endpoints• Examples of endpoint usage

SIP Endpoints

• What is a SIP endpoint?o Uses SIP for session setup

• Is it hardware?

• Is it software?

• Is it always a phone?

Hardware based SIP endpoints

Software based SIP endpoints

Both

SIP endpoints

• What’s in an endpointo Processor

• Softphones and clients take advantage of increasing processor speeds. (video, collaboration, etc.

o Embedded CPU + DSP (Digital Signaling Processor)

• Fading in favor of SOCs

o SOC – System on a Chip• Combines processing with other functions• Brings cost down

OS

• Many environments to develop for.

o WinCEo Linuxo VxWorkso Windowso eCoso More….

Media/Codecs

• Depending on the type of endpoint there are many media types to deal witho G.711o G.729o G.723o iLBCo Speexo Wideband codecso Video (H.263)o Fax (T.38)

Current State

• What have we seen?o A lot of varietyo Unique ideas

• Is there value in copying legacy?o What was right with legacy?

• Hard phone doesn’t crash• Always there (Doh!...I just undocked my PC)

• What does IP and SIP free us up to do?o Some of these devices/applications are making

use of more than SIP.

Protocols and Drafts

• Building on SIP to accomplish much more.• RFCs and Drafts

o Too many to track…o Which will you use?o What is your application?o What kind of foundation in your SIP endpoint

will you build for the future?

• Using other protocols/technologies with SIPo Standards basedo Proprietary

More than just a phone call

• What else can or does and endpoint need?o Presenceo Securityo Wireless/Dual Modeo IMo 3PCCo Application Interactiono Event Notificationo Business Featureso Managemento Diagnostics

Presence

• Use of SIMPLE to expose presenceo 3856 Presence event packageo Subscribe/Notify

• Endpoint usageo Notify that user is at desk typingo Notify my endpoint that a user if free/busy (ie.

Change icon or light lamp.

Security

• Secure media and signaling with standard protocols.o Is it needed or perception?o Can your endpoint handle it?o Can your applications and servers handle it?

• TLS for encrypting SIP signaling• SRTP for encrypting media

Wireless/Dual Mode

• Using SIP and 3GPP to implement IMS applications.

• Endpoint Usageo Switch call between private WLAN and Cellular

network.

Instant Messaging

• Use of SIMPLE to provide instant messaging between SIP endpoints.o Between SIP Clients/endpointso Phones/devices?

• UI challenged (keypad or limited display)

o From an application as a notificationo MultiModal (speech to text, text to speech)

3PCC

• Third party call controlo Manipulate calls at endpointo Multiple drafts

• Endpoint usageo PC client used to control endpoint similar to

CTI/TAPI type of application.• Ex. Answer the phone, initiate dial, etc.

o Allows application integration

Application interaction

• Utilize XML content in SIP messaging to provide endpoint interaction with applications.o BTXML/WML for display content.

• Endpoint usageo Allow endpoint user to interact with vertical

applications targeted for their environment.• i.e. Education, car dealership, etc.

Event Notification

• RFC 3265/3842 for Message Waiting Notification.o This provides the ability for applications to

notify an endpoint of pending messages.• Voice Mail• Offline Instant Messaging

o Can also be used to summarize notifications

Business Features

• SIP-B drafto BLA - Bridged Line Appearanceo IC – Intercomo ACD logino Distinctive ringingo Asserted Identityo Conferencing (Burger Draft)o Call Pickupo More…

• Provides usage and guides for implementing business type features using SIP.

Management and Configuration

• HTML web page for configuration• Telnet for debug• DHCP for retrieving configuration servers• TFTP for downloading configuration• HTTP for downloading configuration• XML configuration files• Binary configuration files

Enough Already

• Just the tip of the iceberg.• Do we just keep piling it on?

o And you thought H.323 was complicated.• Simple vs. Complex endpoints.

o Only make it as complicated as your target audience needs.

• SIP Forum Phone Task Group recently formed.o The purpose of this task group is to define

configuration guidelines, feature set descriptions and interoperability guidelines using SIP.

Questions?

Glossary

• 3PCC – Third Party Call Control• 3GPP – Third Generation Partnership Project• ACD – Automatic Call Distribution• BTXML - Basic Telephony Extended Markup Language• CPU – Central Processing Unit• DHCP – Dynamic Host Configuration Protocol• DMZ – Demilitarized Zone: A networking term for the part of an

enterprise’s network between an external firewall (separating network equipment in the DMZ from the open Internet) and an internal firewall (separating network equipment in the DMZ from the enterprise’s internal LAN)

• DSP – Digital Signal Processor• DTMF – Dual Tone Multi Frequency• G.711 – Codec for 64K PCM speech coding.• G.729 – Codec for 8K ACELP (Algebraically Excited Linear Prediction)

speech coding.• G.723 – Codec for 5.3/6.3 ACELP at 5.3 kbit/s and MP-MLQ at 6.3 kbit/s• GUI – Graphical User Interface• HTTP – Hypertext Transfer Protocol

Glossary cont.

• HTML – Hypertext Markup Language• iLBC – Internet Low Bitrate Codec• IM – Instant Messenging• IMS – IP Multimedia Subsystem• IP – Internet Protocol• NAT – Network Address Translation• RFC – Request for Comment• RTP – Real Time Protocol used for transmission of streaming media such as

voice.• RTCP – Real Time Control Protocol. Accompanies usage of RTP.• SIMPLE – SIP for Instant Messaging and Presence Leveraging Extensions• SIP - Session Initiation Protocol• SIP-B – Session Initiation Protocol for Business Phones• SNMP – Simple Network Management Protocol• SOC – System on a Chip• SRTP – Secure Real Time Protocol• TFTP – Trivial File Transfer Protocol• TLS – Transport Layer Security• XML – Extended Markup Language