The at43 broadband
IP Communications platform

Michael Haberler
IPA/Nic.atInternet Foundation Austria

Introduction - nic.at &IPA
• nic.at is the .at ccTLD registry– about 30 people, 310.000 domains• academic, ISP association background• now subsidiary of the beneficial „Internet
Foundation Austria“• goal– foster Internet development in Austria– operations of critical infrastructure for I(T)SP‘sMärz 2003

mah/AT43
Internet Foundation Austria

2motivation• „IP communications“ (VoIP, Chat/IM,Presence, Video, Gaming) reaches maturity –convergence is happing as we speak– terminals, soft clients, broadband deployment,
codec advances...
– Metcalfe‘s law and the necessity for interworking– unified addressing through ENUM
– ENUM production service start Q2/2004• time to explore the nitty gritty of itMärz 2003

mah/AT43
Internet Foundation Austria

3the at43 project•

prototypical „convergent“ service–assumption – besides Mail and Web IP realtime communications willbe the „third pillar“ of ISP service
speculation: it will be driven by a SIP & ENUM combination„contact is king“––•

foster service development–start in a creative environment which is willing to trade innovation forsome suffering
intended as a copy & paste job blueprint for ISP‘sfür IPA
for us as likely production ENUM registry – a large scale proving
ground for ENUM––••

integrate several user communities by integration into a genericservice platform (universities, ISP‘s, engineering schools)
trial the concept of virtualized SIP/ENUM/PSTN service

März 2003

mah/AT43
Internet Foundation Austria4

services provided by at43
• a point of contact for „sessions“ (speech, chat, video,gaming..)– an URI like sip:j7650719@sip.univie.ac.at• a telephone number to go with it• calls are delivered from PSTN->Internet• Internet->PSTN too – if user has a contract with callby-call telco (10xx access code)• presence service for Instant Messenging• a voice mailbox• a conference bridge IP & PSTN homedMärz 2003

mah/AT43
Internet Foundation Austria

5recap: what is SIP (SessionInitiation Protocol) ?
• how do I address „mobile“ Internet-endpoints?
– natural form is the URI• mailto:mah@eunet.at• sip:j7650719@sip.univie.ac.at– unfortunately the client IP-address varies with location andtime• solution chosen like e-mail:– fixed contact point provided by server– client reports to server periodically– server records „client coordinates“– server can contact client when a session setup „comes in“– protocol flow pretty much like in cellular networks
März 2003

mah/AT43
Internet Foundation Austria

6sessions within a SIP domain

fwd.pulver.com

nic.at43.at
location
register

SIP
server

SIP
serversip:mah@nic.at43.at

sip:mah@nic.at43.atsessionsip:axelm@nic.at43.at

März 2003

sip:mah@nic.at43.at

sip:18341@fwd.pulver.com

mah/AT43

sip:19343@fwd.pulver.com
Internet Foundation Austria

7

... and across domains

nic.at43.at

DNS query for an SRV entry
fwd.pulver.com

fwd.pulver.com
SIP
server

SIP
serversip:19343@fwd.pulver.com

sip:19343@fwd.pulver.com

sessionsip:axelm@nic.at43.at

März 2003

sip:mah@nic.at43.at

sip:18341@fwd.pulver.com

mah/AT43

sip:19343@fwd.pulver.com
Internet Foundation Austria8

so what is ENUM?
• how do I dial an URI when all I have is arotary dial?
– mapping phone number -> URI– domains map names to IP adresses– ENUM maps telephone numbers to URI• using the very same DNS• an ENUM entry might be:• +43 664 4213465 -> sip:mah@nic.at43.at
März 2003

mah/AT43
Internet Foundation Austria

9E.164 addressing with ENUM
ENUM DNS
IN NAPTR 3.0.0.6.3.3.6.6.9.9.5.1.1.3.4.e164.arpa. ?

fwd.pulver.com

nic.at43.at... NAPTR ... "!^.*!sip:mah@nic.at43.at!"

SIP
server

SIP
server+43159966366003

sip:mah@nic.at43.atsessionsip:axelm@nic.at43.at

März 2003

sip:mah@nic.at43.at

sip:18341@fwd.pulver.com

mah/AT43

sip:19343@fwd.pulver.comInternet Foundation Austria

10with ENUM across domain boundaries
ENUM DNS
IN NAPTR 7.3.5.7.3.2.2.4.2.6.0.1.8.7.8.e164.arpa. ?

... NAPTR ... "!^.*!sip:19343@fwd.pulver.com!"

fwd.pulver.com

nic.at43.at
SIP
server

DNS SRV lookup
fwd.pulver.com+878106242237537

SIP
serversip:19343@fwd.pulver.com

sessionsip:axelm@nic.at43.at

März 2003

sip:mah@nic.at43.at

sip:18341@fwd.pulver.com

mah/AT43

sip:19343@fwd.pulver.com
Internet Foundation Austria

11Internet & PSTN: the bridge+43 59966 1234

MediaGateway+43 1 5261670

sip:bert@uni.at

ENUM
DNS+31 20 12345

sip:anne@isp.at+43 59966 5678

März 2003

mah/AT43
Internet Foundation Austria

12calls between PBXes+442079025500

pre WWII
PBX

PSTN+442079025500

AsteriskLinux PBX

AsteriskLinux PBXPCM or SIP or IAX or H.323

PCM or SIP or IAX or H.323

InternetENUM
DNS

März 2003

mah/AT43
Internet Foundation Austria

13

PBX2PBX least cost routing mit ENUM
pre WWII
PBX
PSTN
AsteriskLinux PBX

ENUM

+421257296666

AsteriskLinux PBXPCM or SIP or IAX or H.323

PCM or SIP or IAX or H.323

Internetsip:2666@stuba.sk

IN NAPTR 6.6.6.6.9.2.7.5.2.1.2.4e164.arpa. ?

... NAPTR ... "!¥¥+421257296(.*)$!sip:2¥¥1@stuba.sk!"

März 2003

ENUMDNS

mah/AT43
Internet Foundation Austria

14at43 plan
• nic.at operates service for 2-3 years
together with University of Vienna• integrate new user groups• if a success, finish the project– then the I(T)SP‘s will do it• if a flop, finish the project– then we know how not to do it..
März 2003

mah/AT43Internet Foundation Austria

15

at43 hosting structureUni Wien
RadiusServernumber space
SIP domain
trusted link

ISP 1
RadiusServer

ISP xRadiusServerusermanagement

PSTN
at43 SIP „OEM“ service
PSTN gateway

März 2003

Internet

mah/AT43
Internet Foundation Austria

16

März 2003

mah/AT43
Internet Foundation Austria

17

at43 plug&phone - the ISP
Interface••••external Radius-Server at ISP
number space „loaned“ to ISP by at43
SIP-domain, user management all by the ISP
Radius reply attributes:– telephone number– SIP aliases-Aliases– Call-by-Call Access code (10xx)•••

see http://samuel.ops.at43.at/at43/ (sorry german, but you getthe gist)
installation time < 4hintent is to make learning curve cheap for ISP‘sMärz 2003

mah/AT43Internet Foundation Austria

18

AT43 – signing up with an ISP

Signs upprovisions
account

ISP
account
DBMärz 2003•

Existing or new ISP subscribers sign
up to AT43 services via ISP portal•

ISP assigns phone number, SIP
aliases and Call-by-Call access code•

ISP modifies/adds AT43/SIP relatedparameters to existing subscriber DB•

Subscriber receives config
information (and client software)

mah/AT43
Internet Foundation Austria

19

AT43 – first time login (part1)
ISPaccount
DBISP
RADIUS

OK, +43 59966 366003
Requestsauthentication
Cbc: 1005
Alias: axelm@nic.at

AT43
RADIUSAT43DB•

Users configure AT43 account inaddition to existing ISP services•SIP client logs on to AT43 SIP server•ISP RADIUS server validates user
credentials via AT43 RADIUS proxy•

ISP RADIUS server hands over phone
number, Call-by-Call access code andalias information in response

März 2003

Logs in

AT43 SIP
proxymah/AT43Internet Foundation Austria

20

AT43 – first time login (part2)
ISP
RADIUS

OK, +43 59966 366003
Cbc: 1005
Alias: axelm@nic.at•

User attribute data is stored in AT43
database•

Database entries trigger voicemailbox creation•Entries trigger ENUM DNS entrycration

AT43
RADIUSAT43 SIP
proxy

AT43
Box# 366003 Voice mailENUM
3.0.0.6.6.3.6.6.9.9.5.3.4.e164.arpa DNS server

AT43
DB

Creates entry triggers

ISP
account
DB+43 59966 366003
Cbc: 1005
Alias: axelm@nic.at

Subscriber is now fully provisionedMärz 2003

mah/AT43Internet Foundation Austria21

AT43 – inbound PSTN call•

Gateway provides PSTN access•PSTN user calls +43 59966 366003•Gateway sends INVITE to SIP proxy•SIP proxy performs ENUM lookup•Proxy delivers call, diverts tovoicemail in case oftimeout/busy/not online
INVITE
sip:4359966366003+43 59966 366003
Cbc: 1005
Alias: axelm@nic.at

AT43RADIUS

AT43DB

AT43 SIP
proxy
AT43
Voice mailENUM
DNS server
3.0.0.6.6.3.6.6.9.9.5.3.4.e164.arpa
sip:axelm@nic.at43.at+43 59966 366003

PSTNPSTN
März 2003

mah/AT43Internet Foundation Austria

22

AT43 – outbound PSTN call••••••

User subscribes to Call by Call provider
using assigned number
User communicates Call by Call prefix to ISPUser places call, is authenticated,
Called Station Number is prefixedwith Call by Call operator code if noENUM entry exists
CbC operator identifies user by Calling Station ID
Call is routed AND accounted
through Call by Call operator
No accounting between at43 and user
INVITE

1005066246690

PSTN
PSTN(Call(CallbybyCallCalloperator
operator
1005)
1005)

+43 59966 366003
Cbc: 1005
Alias: axelm@nic.at

AT43RADIUS
AT43 SIPproxy

AT43
DB

CbC
1005

AT43
Voice mailENUM
DNS serverCalls
066246690

Calling Station ID:+43 1 59966 366003+43 1 59966 366003
Joe User, Vienna

März 2003

mah/AT43066246690+43 59966 366003
23Internet Foundation Austria

development direction• client authentication with SIM cards– a single token für WLAN, SIP access– develop key open source components:– EAP-SIM, EAP-AKA supplicant, Radius support• HTTP/AKA SIP authentication (RFC3310)• HTTP/SIM – draft• SMS gatewaying (accounting?)• integration with WLAN roaming
März 2003

mah/AT43Internet Foundation Austria

24

plan and time axis
• University of Vienna – release 12/2002– manage support learning curve– manage terminal availability• ISP workshop– at43 p&p introduction– voice peering – policy draft• integrate other ISP‘s – first half year 2004
• engineering schools – Q3/Q4 2004
März 2003

mah/AT43
Internet Foundation Austria

25

links•••••FreeWorld Dialup Service – www.fwdnet.org
SIP Express router – www.iptel.org
Jasomi NAT Helper – www.jasominetworks.com
Xten SIP clients – www.xten.com
Asterisk ENUM-enabled IP/TDM PBX for Linux –www.asterisk.org• Austrian ENUM Trial website – enum.nic.at• shortly – www.at43.at• enum.nic.at documents – at43 paper, slides
März 2003

mah/AT43Internet Foundation Austria26