Collaboration in the Enterprise1 SIP and Beyond Henning Schulzrinne Department of Computer Science Columbia University Collaboration in the Enterprise February 10, 2005 (Leesburg, VA)

Collaboration in the Enterprise2 Overview SIP as the glue for collaboration Context-aware communications The need for standards in collaboration The future of standards-based collaboration: session mobility central-server conferences application sharing

Collaboration in the Enterprise3 (Early) Adulthood “fully developed and mature” Not quite yet, but no longer a teenager probably need another 6 years to be grown up… Responsibilities: Dealing with elderly relatives  POTS Financial issues  payments, RADIUS Family emergencies  911

Collaboration in the Enterprise4 Evolution of VoIP “amazing – the phone rings” “does it do call transfer?” “how can I make it stop ringing?” catching up with the digital PBX long-distance calling, ca going beyond the black phone

Collaboration in the Enterprise5 Collaboration in transition intra-organization; small number of systems (meeting rooms) inter-organization multiple technology generations diverse end points proprietary (single- vendor) systems standards-based solutions

Collaboration in the Enterprise6 What is SIP? Session Initiation Protocol  protocol that establishes, manages (multimedia) sessions also used for IM, presence & event notification uses SDP to describe multimedia sessions Developed at Columbia U. (with others) started approximately 1996, first standard 1999 Standardized by IETF (RFC et al), ca GPP (for 3G wireless) PacketCable (DCS) About 100 companies produce SIP products Microsoft’s Windows Messenger (≥4.7) includes SIP

Collaboration in the Enterprise7 SIP as service enabler Rendezvous protocol lets users find each other by only knowing a permanent identifier Mobility enabler: personal mobility one person, multiple terminals terminal mobility one terminal, multiple IP addresses session mobility one user, multiple terminals in sequence or in parallel service mobility services move with user

Collaboration in the Enterprise8 Basic SIP message flow

Collaboration in the Enterprise9 SIP – a bi-cultural protocol overlap dialing DTMF carriage key systems notion of lines per-minute billing early media ISUP & BICC interoperation trusted service providers multimedia IM and presence location-based service user-created services decentralized operation everyone equally suspect

Collaboration in the Enterprise10 Presence as communication facilitator

Collaboration in the Enterprise11 Basic presence Role of presence initially: “can I send an instant message and expect a response?” now: “should I use voice or IM? is my call going to interrupt a meeting?” Yahoo, MSN, Skype presence services: on-line & off-line useful in modem days – but many people are (technically) on-line 24x7 thus, need to provide more context + simple status (“not at my desk”) entered manually  rarely correct does not provide enough context for directing interactive communications

Collaboration in the Enterprise12 Presence special case of event notification “user Alice is available for communication” Human users: multiple contacts per presentity device (cell, PDA, phone, …) service (“audio”) activities, current and planned surroundings (noise, privacy, vehicle, …) contact information composing (typing, recording audio/video IM, …) Events in multimedia systems: REFER (call transfer) message waiting indication conference floor control conference membership push-to-talk system configuration General events: emergency alert (“reverse 911”) industrial sensors (“boiler pressure too high”) business events (“more than 20 people waiting for service”)

Collaboration in the Enterprise13 The role of presence Guess-and-ring high probability of failure: “telephone tag” inappropriate time (call during meeting) inappropriate media (audio in public place) current solutions: voice mail  tedious, doesn’t scale, hard to search and catalogue, no indication of when call might be returned automated call back  rarely used, too inflexible  most successful calls are now scheduled by Presence-based facilitates unscheduled communications provide recipient-specific information only contact in real-time if destination is willing and able appropriately use synchronous vs. asynchronous communication guide media use (text vs. audio) predict availability in the near future (timed presence) Prediction: almost all (professional) communication will be presence-initiated or pre-scheduled

Collaboration in the Enterprise14 Context-aware communication context = “the interrelated conditions in which something exists or occurs” anything known about the participants in the (potential) communication relationship both at caller and callee timeCPL capabilitiescaller preferences locationlocation-based call routing location events activity/availabilitypresence sensor data (mood, bio)privacy issues similar to location data

Collaboration in the Enterprise15 Presence data model “calendar”“cell”“manual” audio, video, text video person (presentity) (views) services devices

Collaboration in the Enterprise16 Presence data architecture raw presence document create view (compose) privacy filtering draft-ietf-simple-presence-data-model composition policy privacy policy presence sources XCAP (not defined yet) depends on watcher select best source resolve contradictions PUBLISH

Collaboration in the Enterprise17 Presence data architecture candidate presence document watcher filter raw presence document post-processing composition (merging) final presence document difference to previous notification SUBSCRIBE NOTIFY remove data not of interest watcher

Collaboration in the Enterprise18 RPID = rich presence Provide watchers with better information about the what, where, how of presentities facilitate appropriate communications: “wait until end of meeting” “use text messaging instead of phone call” “make quick call before flight takes off” designed to be derivable from calendar information or provided by sensors in the environment allow filtering by “sphere” – the parts of our life don’t show recreation details to colleagues

Collaboration in the Enterprise19 The role of presence for call routing Two modes: watcher uses presence information to select suitable contacts advisory – caller may not adhere to suggestions and still call when you’re in a meeting user call routing policy informed by presence likely less flexible – machine intelligence “if activities indicate meeting, route to tuple indicating assistant” “try most-recently-active contact first” (seq. forking) LESS translate RPID CPL PA PUBLISH NOTIFY INVITE

Collaboration in the Enterprise20 Rich presence – describing service relationship a communication service offered by a family member associate (colleague) assistant supervisor service-class: type of service offered electronic delivery (courier) postal in-person

Collaboration in the Enterprise21 Rich presence – describing state mood of presentity afraid, amazed, angry, annoyed, anxious, ashamed, bored, brave, calm, cold, confused, contented, cranky, curious, depressed, disappointed, disgusted, distracted, embarrassed, excited, flirtatious, frustrated, grumpy, guilty, happy, hot, humbled, humiliated, hungry, hurt, impressed, in_awe, in_love, indignant, interested, invincible, jealous, lonely, mean, moody, nervous, neutral, offended, playful, proud, relieved, remorseful, restless, sad, sarcastic, serious, shocked, shy, sick, sleepy, stressed, surprised, thirsty, worried likely derived from game state manual input lie detector + fMRI (later)

Collaboration in the Enterprise22 Rich presence – describing activities sphere current state and role free text e.g., “work”, “home”, “soccer club”, “PTA” activities: what is the person doing away, appointment, busy, holiday, in-transit, meal, meeting, on-the-phone, performance, permanent- absence, sleeping, steering, travel, vacation

Collaboration in the Enterprise23 Rich presence – describing place and surroundings place-type: type of surroundings aircraft, airport, bus, car, home, hotel, industrial, library, mall, office, outdoors, public, public- transport, restaurant, school, ship, station, street, theater, train, truck place-is: communication properties video: bright, dark audio: noisy, quiet privacy: communication that is private audio, video, text time-offset: minutes from UTC for avoiding middle-of-the-night calls

Collaboration in the Enterprise24 Rich presence: time information Presence is currently about here and now but often only have (recent) past – e.g., calendar or future “will be traveling in two hours” “will be back shortly” allows watcher to plan communication timed-status time RPID fromuntil now

Collaboration in the Enterprise25 Presence and Privacy All presence data, particularly location, is highly sensitive Basic location object (PIDF-LO) describes distribution (binary) retention duration Policy rules for more detailed access control who can subscribe to my presence who can see what when <gml:Point gml:id="point1“ srsName="epsg:4326"> 37:46:30N 122:25:10W no T04:57:29Z T20:57:29Z

Collaboration in the Enterprise26 Privacy rules Conditions identity, sphere time of day current location identity as or + Actions watcher confirmation Transformations include information reduced accuracy User gets maximum of permissions across all matching rules privacy-safe composition: removal of a rule can only reduce privileges Extendable to new presence data rich presence biological sensors mood sensors

Collaboration in the Enterprise27 Program location-based services

Collaboration in the Enterprise28 On-going IETF work on collaboration Session and service mobility Centralized conferencing Application sharing

Collaboration in the Enterprise29 Service and session mobility Multimedia sessions no longer bound to either desktop or mobile device complementary strengths: mobility vs. large display Service mobility: move service (capabilities, reachability, configuration) temporarily to local device Session mobility: allow active session to move across devices e.g., cell phone call moves to local set of devices and back again

Collaboration in the Enterprise30 Ubiquitous computing SA DA Resource Control (3pcc) Service Location Query SA send audio to SIP UA2 Network Appliance Control SIP UA1 turn on projector SIP UA2call Resource Discovery (SLP UA) audio and video streams Script engine

Collaboration in the Enterprise31 Service scenario Bluetooth Home domain SIP and AAA server Visitor Media streams Call Resource Info Location Resources Use Authenticate Register Info

Collaboration in the Enterprise32 Example: user-adaptive device configuration “all devices that are in the building” RFC 3082? PA device controller SUBSCRIBE to each room SUBSCRIBE to configuration for users currently in rooms 1.discover room URI 2.REGISTER as contact for room URI tftp HTTP SLP signal strength  location REGISTER To: 815cepsr Contact: SIP room 815

Collaboration in the Enterprise33 Application sharing Currently, no good standard for sharing generic applications pixel-based sharing, not shared text editing or other applications designed to be shared T.128 is outdated has limited, special-purpose security integrates poorly with audio/video session setup works poorly across platforms (e.g., fonts) vnc (we use it in our client) only whole screen Working on new sharing model unifies conference sharing and remote access allows large groups (multicast) and centralized conferences supports hybrid video + applications (e.g., embedded movies) leverages existing protocols: RTP for pixel transport SIP for signaling and negotiation PNG for compression

Collaboration in the Enterprise34 Conclusion SIP core component of standards-based multimedia collaboration Dial-and-hope model likely to fade for all but teenager communication (and they are using IM…) maybe even for calling your airline… transition to (rich) presence to find interaction times Most protocol pieces in place, but gaps in centralized conference control & application sharing Implementations still catching up to standards

Collaboration in the Enterprise35 Backups

Collaboration in the Enterprise36 Origins and evolution of SIP multicast multimedia voice (PSTN replacement) 3G (mobile voice) centralized conferencing IM & presence cable VoIP

Collaboration in the Enterprise37 Philosophy Session establishment & event notification Any session type, from audio to circuit emulation Provides application-layer anycast service Provides terminal and session mobility Based on HTTP in syntax, but different in protocol operation Peer-to-peer system, with optional support by proxies even stateful proxies only keep transaction state, not call (session, dialogue) state transaction: single request + retransmissions proxies can be completely stateless

Collaboration in the Enterprise38 IETF efforts SIP, SIPPING and SIMPLE working groups but also XCON (conferencing) Define SIP methods PUBLISH, SUBSCRIBE, NOTIFY GEOPRIV: geospatial privacy location determination via DHCP information delivery via SIP, HTTP, … privacy policies SIMPLE: architecture for events and rich presence configuration (XCAP) session-oriented IM ( ↔ page mode) filtering, rate limiting and authorization

Collaboration in the Enterprise39 Other (implementation) gaps IP phones limited to narrowband audio maybe Skype will provide incentive… echo cancellation still generally iffy configuration harder than necessary NAT traversal no audio/video lip sync poor integration of whiteboards