Deploying IP Telephony

1
Deploying IP Telephony

• Presented by Kundan Singh
• Joint work with Wenyu Jiang, Jonathan Lennox,
  Sankaran Narayanan, Prof. Henning Schulzrinne and
  Xiaotao Wu of Internet Real-Time (IRT) laboratory

10 slides 15 min
2
Overview
What is IP telephony? What to build? How to
deploy? What are the issues?

• Phone call Internet
• User identifier
• Session Initiation Protocol - SIP

office.com
alice_at_columbia.edu
Bob
(2)
(1)
pc4.columbia.edu
(3)
home.com
columbia.edu
3
Personal mobility
What is IP telephony? What to build? How to
deploy? What are the issues?
tel[phone]
yahoo.com
alice_95_at_yahoo.com
Home
alice_at_cs.columbia.edu
tel[phone]
Mobile
desk_at_cs.columbia.edu
cs.columbia.edu
Alice.Cueba_at_cs.columbia.edu
host.cs.columbia.edu
Office
4
Forking, redirection
What is IP telephony? What to build? How to
deploy? What are the issues?
Media path
Control path
Office
Forking
Mobile
Visiting university
Redirect
Bob
columbia.edu
Home
5
Clients and servers
What is IP telephony? What to build? How to
deploy? What are the issues?

• Server
• Proxy, register, redirect.
• Programmable.

• IP phones

Hardware phones
Urgent
SIP server
Phone
script
Low-priority
Voicemail
Software phones
6
More services
What is IP telephony? What to build? How to
deploy? What are the issues?

• Conferencing
• Voice/video mail
• Interactive voice response
• Beyond telephony
• Presence and instant messages
• Integration with web, email
• device control, network games

7
Interworking with regular phone
What is IP telephony? What to build? How to
deploy? What are the issues?
x7040
sipbob_at_cs
(212)5551212
Telephone network (PSTN)
PBX
Telephone subscriber
SIP/PSTN gateway
SIP server
IP endpoint

• Translating
• Audio better codecs on IP
• Signaling some features are lost
• Identifiers phone numbers
• Determining transition points

8
CINEMA
What is IP telephony? What to build? How to
deploy? What are the issues?

• Configuring
• Phones
• Gateway, PBX
• Services, user profiles
• Architecture
• multimedia communication environment
• synchronous asynchronous

More info http//www.cs.columbia.edu/IRT/ci
nema/
User interface http//conductor.cs.columbia.edu/c
inema/
9
Future work
What is IP telephony? What to build? How to
deploy? What are the issues?

• Reliability (network, software)
• QoS (network, media)
• Security (authentication, privacy, attacks)
• System scalability
• Service creation
• Accounting and billing
• Emergency communications
• Integrating with natural environment
• Advanced conference control
• NAT and firewall

10
Summary

• What is IP telephony?
• SIP, personal mobility, email-like identifiers
• What to build?
• Client IP phones proxy and registration server
  conferencing, voicemail, etc.
• How to deploy?
• Gateway to PSTN CINEMA configuration
• More issues
• Reliability, QoS, Security