SIP.edu Speaker: Changyu Wu Adviser: Quincy Wu Date:2006/12/18.
Implementing VoIP at an institution using the SIP.edu - Terena
Transcript of Implementing VoIP at an institution using the SIP.edu - Terena
Dennis Baron, May 14, 2006Page 0np143
SEEREN2 Winter School, Kopaonik, Serbia, VoIP workshop
Dennis Baron
Milivoje Mirovic, AMRES
March 12th, 2007.
Implementing VoIP at an institution using the SIP.edu cookbook
Dennis Baron, May 14, 2006Page 1np143
Motivations• Provides a useful service
• Easy to get started
• Lots of options
• Facilitates inter-campus communications
• Opens the way for innovation
• Build I/T staff skills
• Help break down organization/cultural barriers
• Encourage early technology adopters
• Set PBX migration path
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Means
• Publishing “cookbook” with several alternative “recipes”
• Obtaining corporate sponsorship and promotional pricing
– Cisco, Avaya, etc.
• Build community of SIP practitioners
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Goals
• SIP ConnectivityBuild a large base of SIP-reachable NREN users by making existing campus PBX, Centrex, and VoIP systems reachable via SIP
• SIP AddressingFacilitate the convergence of communications identities by promoting the use of email addresses for voice and multimedia communications
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SIP Connectivity
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Components
• DNS Server– Add SIP SRV records to existing servers
• SIP Proxy Server– Also acts as SIP registrar– Can support “aliases” for legacy phone numbers– Mimics campus dial plan
• LDAP Server (or other source of directory data)– Has mapping of email to phone number
• SIP Gateway– Connects to existing PBX or Centrex– Could also connect to proprietary VoIP system
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PBX PSTN
SIP/PRIGateway
SIP.edu Configuration
SIP Server
Campus Network
Internet2
DNS Server
LDAP Server
SIP user wants to call [email protected]
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PBX PSTN
SIP/PRIGateway
DNS SRV Lookup
SIP Server
DNS Server
LDAP Server
Campus Network
Internet2
DNS SRV
DNS lookup for MIT.EDU
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PBX PSTN
SIP/PRIGateway
SIP INVITE
SIP Server
DNS Server
SIP
LDAP Server
Campus Network
Internet2
SIP INVITE to [email protected]
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PBX PSTN
SIP/PRIGateway
LDAP Lookup
SIP Server
DNS Server
LDAP
LDAP Server
Campus Network
Internet2
LDAP lookup for dbaron – returns x21232
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PBX PSTN
SIP/PRIGateway
Call Sent to PBX Gateway
SIP Server
DNS Server
SIP
LDAP Server
Campus Network
Internet2
SIP INVITE to x21232 via Gateway
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PBX PSTN
SIP/PRIGateway
Media Stream via Gateway to PBX
SIP Server
DNS Server
RTP
LDAP Server
Campus Network
Internet2
SIP user talks to [email protected] x21232
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PBX PSTN
SIP/PRIGateway
Sip to SIP Calling
SIP Server
DNS Server
RTP
LDAP Server
Campus Network
Internet2
SIP user talks to [email protected] his SIP phone
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PBX PSTN
SIP/PRIGateway
SIP to PBX and PSTN Calling
SIP Server
DNS Server
LDAP Server
Campus Network
Internet2
Campus SIP user calls 21232 or 912129990000
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Architecture (Phase 1)
SIPProxyDNS SIP-PBX
Gateway 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
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Call Flow Example
• SIP DNS lookup for MIT.EDU points to SIP proxy
– Sends INVITE to [email protected] to proxy
• SIP proxy checks MIT directory
– Maps call to PBX extension – eg. [email protected]
• SIP proxy checks dial plan
– Routes call to PBX gateway
• PBX rings phone
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DNS
INVITE (sip:[email protected])DNS SRV query
sip.udp.bigu.edu
bigu.edu
SIP User Agent
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
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Examples – Vendor Solution• Avaya
– SIP Converged Communications Server (CCS)
– Communications Manager Media Server and Gateway
• Handle Based Dialing service (LDAP plugin)
SIP~n~Go Starter Kit
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Examples – All-in-One
• Asterisk as both proxy and gateway
• Soekris 4801 server with SangomaT1/E1 card
– Approximately $675USD
• Astlinux (Asterisk + micro Linux)
• Directory lookup via file or LDAP
Still under development and testing
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“gaps”
• SIP is more than voice– Video and IM are important too– Presence services change the user experience
• Chickens without eggs only gets you half way– We’ve made everybody SIP reachable, now who’s going to
call them?
• The 12-digit keypad problem will be with us for awhile
– What do we do until the devices have a 21st century user interface?
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Deployments
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Cookbook Status
See http://mit.edu/sip/sip.edu/
• Sections have been added– Cisco SIP Proxy Server (CSPS)– Cisco Gateways
• Missing pieces– Asterisk gateway
• Some information is over two years old now– Proxy and gateway sections could be updated for current
releases– User agent section is also dated
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Vendor Support SIP.edu work
• Avaya– Developed LDAP plug-in for directory integration– Sponsored first SIP.edu hands-on workshop
• Cisco– Discount package for CSPS
• Comcast– Sponsored first SIP.edu implementers workshop
• Pulver.com– Developed BlueLava package for SER/Asterisk– Workshop support – software and instruction
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Addressing
ISN
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+1-734-352-7031
Deep bureaucratic hierarchy
Telco provider control
The world is flat (almost)
Be your own provider
Radically new devices / services
Old World / New World
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Why Phone NUMBERS?• 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
• It’s time to put E.164 phonenumbers behind us!
• A.G. Bell did not say:
“+1-617-252-1232, come here. I need you!”
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Cell Phones
IP Desk Phones Legacy Desk
Phones
PSTN
Old World*
Emerging New World
Solution:numeric aliases* Transitional period during which we have to
support these devices will last a long time!
How to SIP from a 12-key phone?
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• 4257*260
• ITADs–Defined by Telephony Routing over IP (TRIP) [RFC3219]
–Globally unique –Lots of them (232 - 256)–IANA is already set up to allocate
• ISN resolution works just like ENUM
locallyassigned
IP Telephony Administrative Domain (ITAD)
ITAD Subscriber Numbers (ISN)
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Academic– Internet2– Hofstra University– UCLA– MIT– Stanford– University of Alaska Fairbanks– University of California, Berkeley– Florida State University– University of Manitoba– University of Oregon– Royal Institute of Technology– NE Worcestershire College– Trent University– University of North Carolina– University of Texas, Austin– Columbia University– UCSD– Taiwan Academic Network
Corporate Enterprises– Sterling National Bank– Apple Computer VoIP Service Providers
– Free World Dialup– Stealth Communications– SIPcall.com– RCN Corporation– VoIPteq– SIP Broker
Other– BizFu (web hosting)– Manitoba New Democratic Party– Packet Clearing House– +36 others
VoIP Solution Providers– Tello– Iotum– Digium
Government– State of Oregon
Assigned ITADs (as of 3/15/06)
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• Trial just starting up– Supported by Internet2, Packet Clearing House,
MIT, Tello
• ISN Cookbook Published– Recipes for SER and Asterisk
• 103 ITADs assigned so far– http://www.iana.org/assignments/trip-parameters
ISN Status
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1. Request an ITAD from IANA– Simple piece of email– Approximate two week turnaround
2. Publish your ITAD/ISN information in DNS– Option1: Put full NAPTR in root zone
*.xxx.freenum.org IN NAPTR 100 10 "u" "E2U+sip”"!^\\+*([^\\*]*)!sip:\\[email protected]!" .
– Option2: Have root zone delegate to your own nameservers3. Enable inbound ISN calling4. Enable outbound ISN calling
– Option1: Native ISN lookup– Option2: Using Tello SIP redirector– Option3: Using Tello private ENUM
ISN in Four Easy Steps
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E.164 GDS ISN
+1-734-913-4257
Phone numbers
ITU, national government, …
Hierarchical / geographical
Non-numeric Characters
Ignored No * Only Yes
Varies by country???
00 1 189 7349134257
Public ENUM + multiple private ENUMs
H.323 video users
4257*260
Huh?
IANA
local*domain
With domain owner’s cooperation
ViDeNet, national gatekeepers
Hierarchical / geographical/ organization
One space
With domain owner’s cooperation
One space
SIP AOR
Example [email protected]
Familiarity Email addresses
Delegating Authority
ICANN, TLD registrars
Address Structure
local@domain
Portability With domain owner’s cooperation
Fragmentation One space
E.164 vs. GDS vs. ISN vs. SIP
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ENUM Testing in SIP.edu
So is the answer just another root for .edu?
• Test ENUM server at SipEduEnum.pulver.com
• Test SIP redirect server too
sip:+<countrycode><number>@redirect.SipEduEnum.pulver.com:5062
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– More Information?
• SIP.edu Web Page– http://www.internet2.edu/sip.edu/
• Mailing list (see web page)– mailto:[email protected]
• Thursday conference calls (2:00 Eastern)– sip:[email protected]
• SIP.edu Cookbook– http://mit.edu/sip/sip.edu/
• ISN Cookbook– http://freenum.org/
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– More Information?
Contact:Milivoje Mirovic, [email protected]:[email protected]
Dennis Baron, MITmailto:[email protected]:[email protected]