SIP – dealing with early adulthood Henning Schulzrinne Columbia University SIP 2004 – January 2004 Paris, France.

SIP – dealing with SIP – dealing with early adulthood early adulthood

Henning SchulzrinneColumbia University

SIP 2004 – January 2004Paris, France

(Early) Adulthood(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

OverviewOverview SIP in 2003

Standardization – a long, hard slog Filling in the product palette

finally, cheap phones VoIP (and SIP) over Wi-Fi (802.11) Real deployments

commercial (wireless, consumer, enterprise) Internet2

SIP as a brand: SIPphone, SIPura, SIPquest, SIPCPE, … SIP in 2004

Large-scale consumer usage How much regulation for VoIP? Emergency calling

Major RFCs publishedMajor RFCs published Security mechanism agreement (RFC 3329)

negotiate algorithms with next hop Requirements for resource priority (RFC 3487)

prioritization of calls in military networks and emergencies

REFER method (RFC 3515) call transfer

DHCPv6 for SIP (RFC 3319) automatic outbound proxy configuration

Proxy-to-proxy extensions for PacketCable (RFC 3603)

Symmetric response routing (RFC 3581) improved NAT interaction

Major RFCs publishedMajor RFCs published Service route discovery (RFC 3806)

REGISTER returns “preloaded route” to be used by UA for services SIP and SDP compression (RFC 3485/3486)

compress SIP headers and body via dynamic dictionary Call flows (RFC 3665/3666; actually 2004…)

explain behavior by example useful for testing common cases not a spec replacement

Summary: except for REFER, mostly relevant to subsets of SIP developer community PacketCable 3G Military, emergency response

RFCs in the pipelineRFCs in the pipeline Ready & done, but typically

waiting for normative references Examples:

message waiting indication caller preferences user agent capabilities ENUM for SIP H.323 interworking requirements presence – CPIM, watcher info, …

When are we going to get When are we going to get there?there? In 2003, 6 SIP + 2 SIPPING RFCs published In 2002, 14 SIP + 4 SIPPING RFCs Currently, 24 SIP + 25 SIPPING + 18

SIMPLE WG Internet Drafts does not count individual drafts likely to be

“promoted” to WG status The .com consultant linear extrapolation

technique®

pessimist 8.5 more years if no new work is added to the queue

optimist 4 more years

SIP is PBX/Centrex readySIP is PBX/Centrex readycall waiting/multiple calls

RFC 3261

hold RFC 3264

transfer RFC 3515/Replaces

conference RFC 3261/callee caps

message waiting message summary package

call forward RFC 3261

call park RFC 3515/Replaces

call pickup Replaces

do not disturb RFC 3261

call coverage RFC 3261

from Rohan Mahy’s VON Fall 2003 talk

simultaneous ringing

RFC 3261

basic shared lines

dialog/reg. package

barge-in Join

“Take” Replaces

Shared-line “privacy”

dialog package

divert to admin RFC 3261

intercom URI convention

auto attendant RFC 3261/2833

attendant console

dialog package

night service RFC 3261

centr

ex-s

tyle

featu

res

boss/admin features

attendant features

SIP, SIPPING & SIMPLE –00 draftsSIP, SIPPING & SIMPLE –00 drafts

0

10

20

30

40

50

60

70

1999 2000 2001 2002 2003

SIPSIPPINGSIMPLE

includes draft-ietf-*-00 and draft-personal-*-00

What’s left to do in What’s left to do in SIPPING?SIPPING? Highlights for flavor SIPPING

automated configuration of end systems instead of the current hodge-podge of tftp and HTTP

servers KPML for stimulus control (complements RTP-based) request history: where has this request been and what

was it doing there? SIP-to-QSIG protocol translation end-to-middle security early media: media prior to call completion (enhanced

ringback) conferences

What’s left to do in SIP?What’s left to do in SIP? Call leg manipulation: Replaces, Join headers SIP MIB, 2nd edition SIP over SCTP transport Authenticated identity body (AIB) Globally routable user agent URIs (GRUU)

create new addressable SIP entities on the fly

What’s left – SIMPLEWhat’s left – SIMPLE IM & presence is not a protocol, but an eco system

manage authorizations manage watcher lists selective authorization and content customization need to do equivalent of SMTP + IMAP/POP + ACAP all at

once components in progress:

presence event package meta-events: not user, but system changes event filtering partial notification data element manipulation (XCAP)

manipulate watcher lists and authorization unified approach with GEOPRIV (geo-information authorization)

rich presence

SIP-based conferencesSIP-based conferences Multicast and simple dial-in/dial-out

conferences supported within SIP But need control infrastructure:

access lists (authorization) media mixing topology conference events

users joining and leaving sidebars and similar partial conferences floor control mid-session control of video codecs

Does not strongly depend on signaling protocol IETF XCON working group

but still may use SIP event mechanisms

SIP products beyond $600 office SIP products beyond $600 office phonesphones

Finally, basic IP phones below $100

802.11 phones video conferencing speakerphones $85

SIP product buzzword of the SIP product buzzword of the yearyear Softswitch fading…

need new VC-suitable buzzword

Session border controller as Swiss army knife for today’s broken Internet:

QoS enforcement typically, manages

DiffServ TOS bits NAT control (inbound

calls) IP-IP application-specific

interconnect accounting and statistics

But don’t play nice with encrypted SIP bodies

often weird hybrid of packet inspector, proxy and B2BUA

802.11 + VoIP802.11 + VoIP Most home phones are

cordless phones Homes have multiple phone

plugs, but one broadband access point

Mobile users in warehouses, hospitals, on campuses, …

often, no cell phone coverage Thus, interest in both 802.11-

only and cell 802.11 hand-off

But 802.11 capacity is much smaller than advertised for small (VoIP) packets

channel acquisition time Significant inter-AP hand-off

delays

?

Transition to broadbandTransition to broadband Numbers still small, but moving beyond

exploratory trials to real deployments November 2003: 38% of U.S. home Internet

users connect via broadband (Nielsen/NetRatings)

SIP deployments – landlineSIP deployments – landline Consumer broadband:

Vonage (90,000 lines), Packet8, … buckets of minutes or unlimited long-distance

SIP invisible, but it just works Time-Warner: “Time Warner Cable, the second-largest US

cable group, will [in 2004] roll out a national internet-based telephone service.”

AT&T: “The long-distance giant plans to offer VoIP-enabled services to 1 million consumers in the next two years, beginning with a roll-out in major cities across the U.S. in the first quarter of 2004.”

Verizon MCI Advantage (for business) Focused on hosted SIP services, rather than just SIP

termination Few midsize-to-large companies still considering

traditional circuit-switched PBX for replacement

SIP deployments – wirelessSIP deployments – wireless Usage for controlling new push-to-talk

services not user-visible, but may emerge from

hiding first step to presence-enabled voice services

Sprint PCS Readylink service “first commercial deployment of SIP by a

wireless carrier” 3G (R5) services much slower in coming

Deployment example: Deployment example: SIP.eduSIP.edu Deploy SIP and VoIP across Internet2

educational institutions Transition E.164 SIP URIs But don’t wait for VoIP end system

deployment

“+1-617-637-8562, come here. I need you!”

(from slides by Ben Teitelbaum)

A. G. Bell did not say:

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 SIP.edu Architecture (Phase 1)(Phase 1)

© Ben Teitelbaum, with permission

DNS

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

sip.udp.bigu.edu

bigu.edu

SIP User Agent

SIP.edu Architecture SIP.edu Architecture (Phase 2)(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

© Ben Teitelbaum, with permission

SIP.edu growthSIP.edu growth

http://voip.internet2.edu/SIP.edu/

e.g., sip:[email protected] +1 212 939 7042

Other Internet2 SIP-related Other Internet2 SIP-related effortsefforts Voice disaster recovery for higher-

education community in times of regional or national crisis

principle: two of everything, geographically distributed

inbound and outbound PSTN interworking

College Park, MD & Boston, MA proxies:

primary node at MAX/Georgetown University secondary node at Texas A&M

SIP phones as emergency endpoints

Redundancy modelRedundancy modelSelf Healing

Network Technologies

Redundant BroadWorks

Call ProcessingNodes

Redundant GatewaySwitching

Nodes

HSRP

OSPF IGP

eBGP

RedundantSwitches

RedundantRouters

LAN LAN

DNSSRV

© Internet2, with permission

Internet2 disaster Internet2 disaster recoveryrecovery

Virginia

GU/MAX

Network Gateway

I2

SIP-PRI

Boston

Network Gateway

SIP-PRI

TAMU

PSTN

LAN LAN

from “Disaster Recovery VoIP Trial”, September 2003© Internet2, with permission

Challenges for 2004Challenges for 2004 Completing SIP IM + presence system Regulation

can no longer claim that this is just a toy Emergency calling

easy if local gateway manageable for fixed devices painful in general case redesign of emergency calling

system see talk on Friday

Continued network fragmentation “out-of-box” experience still painful

configuring port forwarding or having another proxy in the DSL modem

Skype (Kazaa) capitalized on NAT traversal dicey network reliability

PSTN regulationPSTN regulation Goals of POTS regulation

ensure competition (Telecommunications Act of 1996) VoIP enhances

ensure customer QoS mainly repairs and reliability, not transmission quality

emergency calling (911, 112) CALEA (lawful intercept) universal service fund

Details differ, but goals in other countries likely similar Staved off regulation for 5 years, but incumbents, states and

communities are getting worried Phone bills are a major tax user fee collection mechanism

school taxes 911 taxes state excise taxes (2.5%) federal taxes (6.5%) …

Universal service fund Universal service fund (US)(US) Universal service

fund high-cost support low-income support rural health care schools and libraries

(E-Rate) 8.7% of interstate Hard to argue with

police departments, rural health clinics and librarians

Purpose 2004 est. (M$)

Schools and libraries

2,046

Rural health care 58

High-Cost 3,223

Low income 653

Total 5,982

ConclusionConclusion SIP standardization moving into clean-up phase

but need continuing contribution now that the exciting pieces are done…

SIMPLE needs to wrap up initial suite, soon competition by XMPP and others

Major deployments starting or on near-term horizon conditions met:

stable protocol version 2 of most products range of CPE options and price points

2004 to be dominated by solving operational problems:

large-scale multi-vendor enterprise deployments provide direction in regulation hopefully,

minimalist