1. Happy Diwali A Festival of Light
Diwali or Deepaawali means an Array of Lamps  i.e .Rows of diyas (Deep = Lamp, Vali =Array). Of all the festivals celebrated in India, Diwali is by far the most glamorous and important. Enthusiastically enjoyed by people of every religion, its magical and radiant touch creates an atmosphere of joy and festivity. As a family festival, it is celebrated 20 days after Dussehra, on the 13th day of the dark fortnight of the month of Ashwin (October / November). This year it falls on 14th Nov. It is a festival of lights symbolizing the victory of righteousness and the lifting of spiritual darkness. It celebrates the victory of good over evil - and the glory of light. This festival commemorates Lord Rama's return to his kingdom Ayodhya after completing his 14-year exile. Homes are decorated, sweets are distributed by everyone and thousands of lamps lit to create a world of fantasy. Diwali is a time for fun and revelry. Diwali is also a time for pooja and tradition.

2. An Overview of CINEMA Implementation
Modules
Applications
Performance
Misc
Compilation
Installation
Portability
Current and Future work
Presented by: Kundan Singh
Joint work with Wenyu Jiang, Jonathan Lennox, Sankaran Narayanan, Henning Schulzrinne and Min Yan
Nov 14, 2001
IRT Group Meeting

3. Overview Multimedia Communication Protocols
Physical layer
Link layer
Network (IPv4, IPv6)
Transport (TCP, UDP)
Application layer
H.323
RTSP
RSVP
RTCP
RTP
Media
G.711
MPEG
SIP
Signaling
Quality of service
Media transport
Internet
Telephony
Radio/TV
Messaging
and Presence
Interactive
voice response
Unified
messaging
Video
conferencing

4. Overview CINEMA - Columbia InterNet Extensible Multimedia Architecture
A flexible architecture to support wide range of multimedia communication applications, both clients and servers
CINEMA Applications
Proxy server, media server, voice mail, conferencing, etc.
CINEMA Libraries
Parsing, SIP, SDP, RTP, mySQL interface, SNMP interface, Portability stubs, etc.

5. Overview SIP and sipd Address based on email (alice@home.com)
DNS home.compc1.home.com
pc1.home.com 
INVITE
INVITE (proxy mode)
office.com
            
Bob
Alice
(2)
(3)
m2.home.com
Columbia.edu
Cisco.com
home.com
sipd

6. Overview sipd – Example scenario
Alice
(8)
(9)
(13)
(6)
(10)
(11)
(12)
(7)
(3)
(4)
(5)
Bob
(2)
(1)

7. An Overview of CINEMA Implementation
Modules
Applications
Performance
Misc
Compilation
Installation
Portability
Current and Future work
Various CINEMA libraries and their functionality

8. Modules Functionality
Message parsing: SIP, RTSP
Transaction state and client branch
User agent call state
Interface to external modules: database, SNMP
Higher level policy: sip-cgi
Canonicalize: e.g., Henning.Schulzrinne => hgs
Authentication: basic, digest

9. Modules Message Parsing (libcine)
HTTP
GET /sip HTTP/1.0
Host: …
DESCRIBE rtsp://… RTSP/1.0
Accept: application/sdp …
RTSP
SIP
INVITE sip:… SIP/2.0
From: …
Utilities for URL, headers, constructing and parsing messages

10. Modules Transaction state (libsip)
A request and all its responses
RTSP vs SIP requests
Request can be
Proxied
Redirected
Generated
Terminated

11. Modules Call state (libsip++)

12. Modules canonicalization [libcanon]
Bob.Wilson
canonicalize

13. Modules Libraries
sipd
sip323
sipconf
sipum
sipvxml
rtspd
CINEMA Libraries
libNT
Win32 stub
libcine
Utilities parsing
IPv6
libsip
Basic SIP library
libsip++
SIP UA library
libmixer
RTP audio mixer
libdict
Hash table
libdb++
mySQL intf
RTSP media
server
SIP proxy
SIP/H.323
gateway
SIP/RTP
conferencing
SIP/RTSP
unified messaging
SIP/VoiceXML
browser
LDAP
Xerces-C
OpenH323
MySQL
PWLib
Resparse
librtsp
RTSP
client
librtp
RTP library
libsnmp
SIP MIB
ViaVoice
CINEMA Applications
Parsing, SIP, SDP, RTP, mySQL interface, SNMP interface, Portability stubs, etc.

14. Modules Layered structure
Other Applications
RTSP server
SIPUA
API
SIP
proxy
RTSP API
RTP
Interface
RTSP transaction
HTTP Message Parsing
SIP transaction
Client Branch
Transport layer (TCP/UDP)

15. An Overview of CINEMA Implementation
Modules
Applications
Performance
Misc
Compilation
Installation
Portability
Current and Future work
Our test-bed architecture and its components

16. Test-bed Architecture
OpenSource SQL database: MySQL
User information:
Contact location
Profile (e.g., password)
Aliases
Address book
System information
Configuration
SIP proxy,
redirect
server
SQL
database
sipd
Proxy, Redirect, Registration server.
Authentication
Programmable (SIP- CGI)

17. Test-bed Architecture
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
User profile can be modified using web browser.
Creating new user (admin/normal)
Changing profile and contact information (“follow me” service).
Web CGI scripts
Both sipd and web scripts use the database

18. Test-bed Architecture
IP phones connected to the departmental LAN. Users are identified by id, e.g.,
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
Software (sipc) for desktop. Allows audio, video, chat, white board, device control, instant message, presence and desktop sharing.

19. Test-bed Architecture
Registration can also be altered from the web interface
Web based
configuration
Web server
Phones register themselves with sipd when powered up.
SIP proxy,
redirect
server
SQL
database
sipd
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
Phones
Sipd stores the contact information in the database table:
=>
There can be multiple contacts. All registered phones ring, and the first to pick up is connected.

20. Test-bed Architecture
Another IP phone
(1) When somebody calls sipd gets the INVITE message and “proxies” the call to the current location.
Web based
configuration
Web server
(2) Phone rings, the user picks up the call and can talk to the caller.
SIP proxy,
redirect
server
SQL
database
sipd
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
Phones
Based on user profile, sipd may ask for caller authentication.

21. Test-bed Architecture
Telephone
Telephone
switch
External T1
Departmental PBX (Nortel Meridian) connects both internal and external lines to the gateway.
Dial “8” to reach outside line
Department
PBX
Web based
configuration
Web server
Internal T1
SIP proxy,
redirect
server
SQL
database
sipd
(Extension:713x)
T1/E1
RTP/SIP
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
Cisco 2600 router with SIP/PSTN gateway connects the departmental LAN with the PBX.

22. Test-bed Architecture
Dials
Telephone
Telephone
switch
(1) When PBX receives a call for , it forwards the call to extension is assigned to the gateway.
Department
PBX
Web based
configuration
Web server
Internal T1
SIP proxy,
redirect
server
SQL
database
sipd
(Extension:713x)
T1/E1
RTP/SIP
(2) The gateway forwards all PSTN calls to sipd;
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
(3) Sipd looks into the dialplan, finds a mapping and forwards the call to the current location of “hgs”.

23. Test-bed Architecture
Telephone
Telephone
switch
(4) PSTN user receives the call.
External T1
Dial “8” to reach outside line
(3) PBX forwards the call to external line.
Department
PBX
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
(2) Sipd authenticates the caller and checks permissions.
Sipd maps the number to adding the prefix “8” and the gateway address.
T1/E1
RTP/SIP
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
(1) The IP user dials

24. Test-bed Architecture
Telephone
Telephone
switch
Telephone number mappings and privileges modifiable from the web
External T1
Department
PBX
Web based
configuration
Web server
Internal T1
SIP proxy,
redirect
server
SQL
database
sipd
T1/E1
RTP/SIP
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
Can use no-DID (direct inward dialing) mode for more numbers.

25. Additional Services Advantage: cost savings + new services
“Think of receiving your voic messages in an that you can later play out in a conference to show it to others”
Easy integration of , web, instant messaging, etc.
Open architecture vs Close architecture (traditional telephones)

26. Test-bed Architecture
Telephone
Telephone
switch
Programmable server:
SIP-CGI and Call Processing Language (CPL)
Department
PBX
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
T1/E1
RTP/SIP
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
Scripts can be uploaded by clients also.

27. Test-bed Architecture
Telephone
Telephone
switch
SNMP agent for SIP MIB. Allows remote monitoring and control of the SIP server. (e.g., prompt when an unauthorized registration is attempted)
Department
PBX
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
T1/E1
RTP/SIP
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
SNMP
(Network
Management)

28. Test-bed Architecture
Telephone
Telephone
switch
Allows an H323 client (Netmeeting) to use the services of our SIP infrastructure.
Department
PBX
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
T1/E1
RTP/SIP
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
SIPH.323
convertor
NetMeeting
siph323
H.323
SNMP
(Network
Management)

29. Test-bed Architecture
Telephone
Telephone
switch
rtspd
SIP/RTSP
Unified
messaging
RTSP media
server
sipum
Quicktime
RTSP clients
RTSP
Generic media server for playback and recording of messages. Can work with existing RTSP client, Apple’s QuickTime.
Department
PBX
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
T1/E1
RTP/SIP
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
SIPH.323
convertor
NetMeeting
siph323
H.323
SNMP
(Network
Management)
Provides a voice mail and answering machine service to all the registered users. Has web interface for accessing voice mails.

30. Test-bed Architecture
Telephone
Telephone
switch
rtspd
SIP/RTSP
Unified
messaging
RTSP media
server
sipum
Quicktime
RTSP clients
RTSP
Centralized conferencing server for audio and video. Users can join from IP as well as PSTN.
SIP
conference
server
sipconf
Department
PBX
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
T1/E1
RTP/SIP
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
SIPH.323
convertor
NetMeeting
siph323
H.323
SNMP
(Network
Management)

31. Test-bed Architecture
Sipd maps 7139=>
Telephone
Telephone
switch
PSTN user dials
rtspd
SIP/RTSP
Unified
messaging
RTSP media
server
sipum
Quicktime
RTSP clients
RTSP
SIP
conference
server
sipconf
Department
PBX
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
T1/E1
RTP/SIP
Netmeeting user dials
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
SIPH.323
convertor
NetMeeting
siph323
H.323
SNMP
(Network
Management)
SIP user dials

32. Our IP telephony test-bed
Telephone
Telephone
switch
rtspd
SIP/RTSP
Unified
messaging
RTSP media
server
sipum
Quicktime
RTSP clients
RTSP
SIP
conference
server
sipconf
Department
PBX
Web based
configuration
Web server
SIP proxy,
redirect
server
SQL
database
sipd
T1/E1
RTP/SIP
e*phone
sipc
Software SIP
user agents
Hardware
Internet (SIP)
phones
SIP/PSTN Gateway
SIPH.323
convertor
NetMeeting
siph323
H.323
SNMP
(Network
Management)
Device GW
X 10
W. Jiang, J. Lennox, H. Schulzrinne and K. Singh, “Towards Junking the PBX: Deploying IP Telephony". NOSSDAV 2001,

33. PSTN to IP Call 1 2 3 5 4 Direct Inward Dial (DID) - direct and simple
PBX
PSTN
External T1/CAS
Regular phone
(internal)
Call 1
Gateway
Internal T1/CAS
(Ext: )
Call 7134 2
713x is called a part of Coordinated Dial Plan (CDP) in a Nortel PBX
SIP server
sipd
Ethernet 3
sipc 5
Bob’s phone
SQL
database 4
7134 => bob
Direct Inward Dial (DID) - direct and simple
No-DID - dial extension, supports more users

34. IP to PSTN Call
PBX
Internal T1/CAS
Call 4
Regular phone
(internal, 7054)
PSTN
External T1/CAS
Call 5
Gateway
( ) 3
Ethernet
SIP server
sipd
sipc 1
Bob calls
SQL
database 2
Use
Note: In this direction there is no distinction between DID and non-DID calls.

35. An Overview of CINEMA Implementation
Modules
Applications
Performance
Misc
Compilation
Installation
Portability
Current and Future work
Discussion of some performance issues and solutions

36. Performance Why is it important ?
Reduce server cost per user => more users per server
Registration: 100 requests/s => registered users (1 hr refresh time, digest authentication)
Call: 100 requests/s => calls per hour (record route)
Bandwidth: 1 Gb/s => (approx) 6250 bi-directional G.711 simultaneous participants in a conference.

37. Performance For which components ?
Signaling: proxy, registrar (sipd)
Receive message
Act on it (canonicalize, database lookup)
Proxy the message
Send/proxy response back
Media: sipconf, rtspd
Some processing for each media stream
File I/O
Encode/decode (audio mixing)
Forward packets (video)

38. Performance Threads One thread per request Customize stack size
For 1MB virtual memory per thread on 32 bit machine: max limit of 4000 threads. OS limits (for regular user 1024 pthreads on solaris)
30 second wait per stateful INVITE request; limits to 130 R/s
Thread creation overhead
Customize stack size
Use thread pool or event model

39. Performance Thread pool
Request are put in an event queue
Worker threads pick up the event and execute
Fix the number of worker threads
G/G/T/N queue
Use thread pool for all requests
Need to rewrite sleep/wakeup so that 30 sec wait does not waste a thread
Will multiple process help? may be for stateless proxies

40. Performance In-memory DB
Every query to database affects turn-around time
Duplicate the DB in main memory; hash-table
Less than 4k per user (?)
Replacement algorithm? Not needed
Synchronization: separate threads
Primary user table, aliases: relatively static, readonly by sipd, refresh every 30 min
Contacts table: read-write, refreshed every 2 min
Read only modified records since last read, write back only modified records

41. Performance Database NFS issues (log, scripts, database files?)
SQL logging: currently serialized; use lazy write back; logging at the end of request processing, so it does not affect response time but consumes resources (worker thread) for longer time per request
DB on same machine or on remote machine?

42. Performance Bandwidth
Assuming avg message length 130 bytes; on 100 Mb/s with effective 40%, 3000 requests/s
Affects more to media components
Number of simultaneous media streams served by rtspd
Number of participants in a conference by sipconf
Number of simultaneous three party conferences by sipconf

43. Performance General Comments
Measure performance on various platforms (Linux, Solaris Netra, Dec Alpha)
Compare stateless vs stateful proxy
Compare in-memory (fastsql) vs database (sql)

44. An Overview of CINEMA Implementation
Modules
Applications
Performance
Misc
Compilation
Installation
Portability
Current and Future work

45. Compilation Autoconf, configure and make for Unix platforms
Solaris, Linux, FreeBSD, Tru64
$ ./configure –with-mysql=… --with-…
$ make sipconf
Microsoft VC for Windows NT/2000
Makefile.in (global), module.mk (per module)

46. Installation And software distribution
GUI based configuration
Package manager (Sun, Linux, FreeBSD,…), Installation scripts, windows install shield
Monitor scripts, RC

47. Portability Cross platform support
Endian-ness: Big endian (Sparc, DEC), little endian (Intel)
32 bit vs 64 bit
Unix vs Windows standard libraries (threads)
Re-entrant APIs (gethostbyname_r, strtok_r)
NTutils for win32
Shared libraries compilation (?)

48. Documentation software documentation: Overview:
Overview:
Paper:
Tech report (incomplete):
Compilation instructions:
README, README.build, NT/README.win32 files
This presentation:
(will be put up shortly)

49. Current and Future Work
Improved installation
Address book
Calendar and event notification
Conference recording (local file, media server)
File sharing in a conference from web
Voice dialogs for conferencing and voic
Load balancing on multiple conference servers
Conference (floor) control from web

50. Current and Future Work
From a multimedia communication test bed to a multimedia collaboration portal environment
Scaling to large call volumes and users

51. Publications For more information
W. Jiang, J. Lennox, H. Schulzrinne and K. Singh, “Towards Junking the PBX: Deploying IP Telephony". NOSSDAV 2001,
H. Schulzrinne, S. Narayanan, J. Lennox and M. Doyle, “SIPstone – Benchmarking SIP Server Performance”. Aug
Kundan Singh, Gautam Nair and Henning Schulzrinne, "Centralized Conferencing using SIP". Proceedings of the 2nd IP-Telephony Workshop (IPTel'2001), April 2001.
K. Singh, H.Schulzrinne, "Interworking Between SIP/SDP and H.323". Proceedings of the 1st IP-Telephony Workshop (IPTel'2000), April 2000.
Kundan Singh and Henning Schulzrinne, "Unified Messaging using SIP and RTSP".  IP Telecom Services Workshop 2000, Sept Atlanta, Georgia, U.S.A.