22 july 2003 internet2, connectivity, and advanced interpersonal communications ben teitelbaum

22 July 2003

Internet2, Connectivity, and Advanced Interpersonal Communications

Ben Teitelbaum <[email protected]>

www.internet2.edu“Inernet2, Connectivity, and Advanced Interpersonal Communications”

Outline

Better Voice Through IP

A Look Back Over Our Shoulders

Connectivity is Key

What Internet2 Brings to the Table

Some Guiding Principles

New Internet2 Voice Activities


The Opportunity

Voice has been and will be a “killer app” for a long, long time

• Per-capita, daily US land-line use: 45 minutes• Per-capita, daily US wireless use: 16 minutes• Overall, per-capita minutes continue to grow

Let’s make it better!• Fidelity• Privacy• Addressing• Mobility• Survivability • Presence


Better Voice Through IP: Fidelity & Privacy

Fidelity• Why chop off voice at 4kHz? Most power is under

4kHz, but wideband definitely improves intelligibility and comfort.

• Also, we have two of these marvelous sensory organs! – Synthetic spatial placement of audio conference participants?

Privacy• Calls over the PSTN may be encrypted, but it’s easier with VoIP• “Phones” are already general purpose computers• Users are likely to have the public keys of their correspondents in

their computing environment for other reasons (secure email, IM)


Better Voice Through IP: Addressing

Addressing• Users should not be burdened with device addresses, when it’s people they really care about

• Addresses should be mnemonic and empower enterprises to manage the identities of their users–sip:[email protected]

• It’s time to put E.164 phonenumbers behind us!

• A.G. Bell did not say: “+1-212-637-8562, come here. I need you!”


Better Voice Through IP: Mobility

Mobility• Not just spatial mobility (as with a cell phone)• Also, device mobility

–Users are known by one address regardless of which devices or media they use

• Also, media mobility –Seamless gatewaying between media types–For example: voice ↔ IM


Better Voice Through IP: Survivability

Survivability• PSTN has vulnerable single points of failure

–Central office (CO) and local loop

• Internet –Designed to heal

• Though route stability and convergence times could be better

–Can handle much higher call volumes• Packet level multiplexing and adaptive, loss tolerant codecs• Highly scalable, fault tolerant signalling built from commodity PCs

–Gradual degradation of voice quality, rather than call blocking is what you want in an emergency

• Combining VoIP and PSTN results in better voice survivability than either architecture can deliver alone


Better Voice Through IP: Presence

Presence• “Notification of events that facilitate communication” (Henning Schulzrinne)

–“On-line”, “Away”, “Idle”, “On phone”, “Out to lunch”, ...

• Back to the future–Remember: finger, write, who?–Presence restores the sense of community that existed on

timesharing systems

• Forward to the future–New standards for interoperability and scalability–User-controlled policies to provide custom views to watchers–Richer state semantics and automatic triggers


Rich Presence

Automatic notification from many sources…

• Location beacons • Facial recognition systems• Phones• Calendar• …

Not all watchers are human• Software agents may watch

presence and route/initiate calls appropriately (e.g. below)

Watch and initiate a voice conference when everyone is available


Presence as Glue*

presence

text --------------------- image ------------------- voice

email

instant messaging

directories

calendaring

video

3G cellular

conferencing

soft/hard phones

voice mail

* This slide courtesy of Jeremy George


So What Will the Future Look Like?

Although preceding “Better Voice Through IP” slides illustrate some potentially fruitful directions, I really haven’t a clue what the future holds!

Before setting out to nurture innovative new IP voice applications, it’s useful to consider the history of earlier communications technologies…


Early History of the Telephone

For the first 30 years of the telephone, promoters struggled to identify the killer application that would promote its wide adoption by home owners and businesses. At first the telephone was promoted as a replacement for the telegraph, allowing businesses to send messages more easily and without an operator. Telephone promoters in the early years touted the telephone as a new service to broadcast news, concerts, church services, weather reports, etc. Industry journals publicized inventive uses of the telephone such as sales by telephone, consulting with doctors, ordering groceries over the telephone, listening to school lectures and even long distance Christian Science healing! The concept that someone would buy the telephone to chat was simply inconceivable at that time.

C. Fischer, America Calling (paraphrased by Bill St Arnaud)


Other Earlier Communications Technologies

Email• The popularity of email was not foreseen by the ARPANET's

planners. Roberts had not included electronic mail in the original blueprint for the network. In fact, in 1967 he had called the ability to send messages between users “not an important motivation for a network of scientific computers” . . . . Why then was the popularity of email such a surprise? One answer is that it represented a radical shift in the ARPANET's identity and purpose. The rationale for building the network had focused on providing access to computers rather than to people.

J. Abbate, Inventing the Internet

Peer-to-peer file sharing• Again, not foreseen• Internet2 connectivity + directory services (Napster, etc.)


And the Moral Is…

Business and technology leaders…• …have a poor track record of predicting how new communications technologies will be used

• …tend to underestimate social or seemingly “frivolous” uses of new technologies and overestimate the importance of content

Users are highly motivated to communicate with each other, if only they can connect


Connectivity is Key

Network connectivity• Can connections be established between communicating IP

addresses with high-performance and high-availability?

Application connectivity• Do devices and applications have good network connectivity?• Are there protocols and call routing infrastructure to establish

connections between communing applications?

User connectivity• Can I

reach you?

Address

Presence

Address

Presence

Application Connectivity

Network ConnectivityApp

lica

tion A

pplica

tion

(call and presence routing)

(high-performance, end-to-end IP transit)

Use

r Use

r


What Internet2 Brings to the Table

Eager adopters• ~4 million students• Strong institutional commitments to advance IP communications and promote collaborative apps

Connectivity• Great networking connectivity

–High-bandwidth, low-loss, low-jitter –End-to-end transparency (few NATs)–IPv6 and multicast too!

• We are committed to advancing higher-level connectivity

26% of college students use IM (twice the rate of average Internet users)*

* The Internet Goes to College, Pew Internet and American Life Project report, Sept. 2002.


Internet2 Voice: Guiding Principles

Voice Can Be Advanced• Many ways to make voice better

– fidelity, privacy, addressing, mobility, survivability, presence

• Internet2 VoIP is not about cheap phone calls!

Connectivity First, New Services Later• Innovation occurs at the edge, but requires connectivity• Good network connectivity not sufficient• Also need application-layer connectivity and (ultimately) user-layer connectivity


Several New Internet2 Activities

SIP.edu• Leader: Dennis Baron <[email protected]>

Presence and Integrated Communications WG•Chair: Jeremy George <[email protected]>

Voice survivability• Leader: Chris Peabody <[email protected]>


SIP.edu

Goals• Grow SIP connectivity in Internet2• Increase value proposition for end-user SIP adoption• Promote convergence of voice and email identity• Low entry-cost means for campuses to...

–Provide a useful service–Get their feet wet with SIP

Means• Publishing “cookbook” with several alternative “recipes”• Obtaining corporate sponsorship and promotional pricing


SIPProxy

DNSSIP-PBXGateway

PBX

INVITE (sip:[email protected])

INVITE(sip:[email protected])

DNS SRV query sip.udp.bigu.edu

telephoneNumberwhere mail=”bob”

PRI / CASbigu.edu

CampusDirectory

SIP User Agent

Bob's Phone

SIP.edu Architecture (Phase 1)


DNS

INVITE (sip:[email protected])DNS SRV query

sip.udp.bigu.edu

bigu.edu

SIP User Agent

SIP.edu Architecture (Phase 2)

locationDB

If Bob has registered, ring his SIP phone; Else, call his extension through the PBX.

REGISTER(Contact: 207.75.164.131)

INVITE (sip:[email protected])

SIPProxy

SIPRegistrar

Bob's SIP Phone


Presence and Integrated Communications

Newly chartered “PIC” working group

Foci• Presence• Instant messaging• Integrated communications

First-year Deliverables• Rich Presence and Integrated Communications Demonstration (Internet2 Member Meeting, Fall 2003)

• Engineering and management-level tutorials (Spring 2004)


Voice Survivability

Broadsoft/PAETEC/Georgetown Trial • SIP-based voice disaster recovery trial• Emergency phones on GU campus• Redundant Broadworks server nodes• Redundant PAETEC gateways in separate COs

Voice survivability and disaster recovery is increasingly a big deal for Internet2 schools

• Other projects in this area are anticipated


For More Information

Voice Over IP Working Group• http://voip.internet2.edu/

Presence and Integrated Communications WG • http://pic.internet2.edu/

Great SIP tutorial• http://www.iptel.org/sip/

Other sources• J. Abbate, Inventing the Internet, MIT Press, Cambridge, Mass., 1999.• C.S. Fischer, America Calling: A Social History of the Telephone to

1940, University of California Press, Berkeley, 1992.• A. Odlyzko, Content is Not King, First Monday, Vol. 6, No. 2, 2001.

http://voip.internet2.edu/

http://pic.internet2.edu/

http://www.iptel.org/sip/

www.internet2.edu


SIP Attributes

Component protocol that provides • User registration and mobility• Call routing, setup, tear down, and redirection

Makes heavy use of existing standards• SDP • RTP • MIME • DNS • UDP • TRIP

Easy and familiar feel• Textual encoding • Email-style headers • HTTP-style error codes •

URL addresses

Signaling and media paths separate• Signaling through servers for mobility and call services• Media on direct path for low RTT


SIP Components

User Agent (UA)• Hard or soft phones that initiate and receive calls• Media to exchange is negotiated P2P between UAs

Registrar Server• Authenticates and accepts registration requests from UAs• Maintains location DB binding user to one or more registered UAs

Proxy Server• Routes calls (possibly through a chain of proxies) to UA• Keeps no session state (for scalability)

Redirect Server• Replies to calling UA with a redirect

Server functionality is typically bundled

22 july 2003 internet2, connectivity, and advanced interpersonal communications ben teitelbaum

Documents

better voice survivability

voice im slide

opportunity voice

mobility mobility

shoulders connectivity

spatial mobility

device mobility users

addressing users