Implementing VoIP at an institution using the SIP.edu cookbook

Transcription

1 Implementing VoIP at an institution using the SIP.edu cookbook SEEREN2 Winter School, Kopaonik, Serbia, VoIP workshop Dennis Baron Milivoje Mirovic, AMRES March 12 th, Page 0

2 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 Page 1

3 Means Publishing cookbook with several alternative recipes Obtaining corporate sponsorship and promotional pricing Cisco, Avaya, etc. Build community of SIP practitioners Page 2

4 Goals SIP Connectivity Build a large base of SIP-reachable NREN users by making existing campus PBX, Centrex, and VoIP systems reachable via SIP SIP Addressing Facilitate the convergence of communications identities by promoting the use of addresses for voice and multimedia communications Page 3

5 SIP Connectivity Page 4

6 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 to phone number SIP Gateway Connects to existing PBX or Centrex Could also connect to proprietary VoIP system Page 5

7 SIP.edu Configuration SIP Server Internet2 Campus Network SIP user wants to call DNS Server SIP/PRI Gateway LDAP Server PBX PSTN Page 6

8 DNS SRV Lookup DNS SRV Internet2 SIP Server Campus Network DNS lookup for MIT.EDU DNS Server SIP/PRI Gateway LDAP Server PBX PSTN Page 7

9 SIP INVITE Internet2 SIP SIP Server Campus Network SIP INVITE to DNS Server SIP/PRI Gateway LDAP Server PBX PSTN Page 8

10 LDAP Lookup Internet2 SIP Server LDAP Campus Network LDAP lookup for dbaron returns x21232 DNS Server SIP/PRI Gateway LDAP Server PBX PSTN Page 9

11 Call Sent to PBX Gateway SIP Server Internet2 Campus Network SIP INVITE to x21232 via Gateway DNS Server SIP SIP/PRI Gateway LDAP Server PBX PSTN Page 10

12 Media Stream via Gateway to PBX Internet2 RTP SIP Server Campus Network SIP user talks to at x21232 DNS Server SIP/PRI Gateway LDAP Server PBX PSTN Page 11

13 Sip to SIP Calling Internet2 RTP SIP Server Campus Network SIP user talks to at his SIP phone DNS Server SIP/PRI Gateway LDAP Server PBX PSTN Page 12

14 SIP to PBX and PSTN Calling SIP Server Internet2 Campus Network Campus SIP user calls or DNS Server SIP/PRI Gateway LDAP Server PBX PSTN Page 13

15 Architecture (Phase 1) SIP User Agent DNS SRV query sip.udp.bigu.edu INVITE DNS SIP Proxy INVITE SIP-PBX Gateway PRI / CAS PBX bigu.edu telephonenumber where mail= bob Campus Directory Bob's Phone Page 14

16 Call Flow Example SIP DNS lookup for MIT.EDU points to SIP proxy Sends INVITE to to proxy SIP proxy checks MIT directory Maps call to PBX extension eg. SIP proxy checks dial plan Routes call to PBX gateway PBX rings phone Page 15

17 Architecture (Phase 2) SIP User Agent DNS DNS SRV query sip.udp.bigu.edu SIP Proxy INVITE If Bob has registered, ring his SIP phone; Else, call his extension through the PBX. INVITE bigu.edu location DB SIP Registrar REGISTER (Contact: ) Bob's SIP Phone Page 16

18 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 Page 17

19 Examples All-in-One Asterisk as both proxy and gateway Soekris 4801 server with Sangoma T1/E1 card Approximately $675USD Astlinux (Asterisk + micro Linux) Directory lookup via file or LDAP Still under development and testing Page 18

20 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 21 st century user interface? Page 19

21 Deployments Page 20

22 Cookbook Status See 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 Page 21

23 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 Page 22

24 Addressing ISN Page 23

25 Old World / New World Radically new devices / services Deep bureaucratic hierarchy ben@internet2.edu The world is flat (almost) Telco provider control Be your own provider Page 24

26 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 sip:dbaron@mit.edu It s time to put E.164 phone numbers behind us! A.G. Bell did not say: , come here. I need you! Page 25

27 How to SIP from a 12-key phone? Old World* IP Desk Phones Legacy Desk Phones Cell Phones Emerging New World PSTN * Transitional period during which we have to support these devices will last a long time! Solution: numeric aliases Page 26

28 ITAD Subscriber Numbers (ISN) 4257*260 locally assigned IP Telephony Administrative Domain (ITAD) ITADs Defined by Telephony Routing over IP (TRIP) [RFC3219] Globally unique Lots of them ( ) IANA is already set up to allocate ISN resolution works just like ENUM Page 27

29 Assigned ITADs (as of 3/15/06) 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 Corporate Enterprises Sterling National Bank Apple Computer VoIP Service Providers Free World Dialup Government State of Oregon University of Texas, Austin Other Columbia University BizFu (web hosting) UCSD Manitoba New Democratic Party Taiwan Academic Network Packet Clearing House +36 others Stealth Communications SIPcall.com RCN Corporation VoIPteq SIP Broker VoIP Solution Providers Tello Iotum Digium Page 28

30 ISN Status 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 Page 29

31 ISN in Four Easy Steps 1. Request an ITAD from IANA Simple piece of Approximate two week turnaround 2. Publish your ITAD/ISN information in DNS Option1: Put full NAPTR in root zone *.xxx.freenum.org IN NAPTR "u" "E2U+sip Option2: Have root zone delegate to your own nameservers 3. Enable inbound ISN calling 4. Enable outbound ISN calling Option1: Native ISN lookup Option2: Using Tello SIP redirector Option3: Using Tello private ENUM Page 30

32 E.164 vs. GDS vs. ISN vs. SIP E.164 GDS ISN SIP AOR Example *260 bdr@internet2.edu Familiarity Phone numbers H.323 video users Huh? addresses Delegating Authority ITU, national government, ViDeNet, national gatekeepers IANA ICANN, TLD registrars Address Structure Non-numeric Characters Portability Hierarchical / geographical Ignored No * Only Yes Varies by country??? Hierarchical / geographical/ organization With domain owner s cooperation local*domain local@domain With domain owner s cooperation With domain owner s cooperation Fragmentation Public ENUM + multiple private ENUMs One space One space One space Page 31

33 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 Page 32

34 More Information? SIP.edu Web Page Mailing list (see web page) Thursday conference calls (2:00 Eastern) SIP.edu Cookbook ISN Cookbook Page 33

35 More Information? Contact: Milivoje Mirovic, AMRES Dennis Baron, MIT Page 34