SIP Protocol

1
SIP Protocol

• An Application layer Protocol
• Establishes, manages, and terminates a multimedia
  session(call).
• Can be used to create two-party, multiparty, or
  multicast sessions
• Independent of underlying transport layer (I.e.,
  it can run on either UDP, TCP)
• SIP Messages INVITE, ACK, BYE, OPTIONS(queries a
  machine about its capabilities), CANCEL(cancels
  an already started initialization process),
  REGISTER

2
Project Objectives

• Add the following functionalities to the supplied
  configuration
• Allow user to forward a call to another user
  (call forwarding)
• Allow user to define a black list(call blocking)
• Calculate the bills for call (billing)

3
SIP Addresses

• SIP gives sender and receiver a globally
  reachable address (URI)
• Bind to this address using registrar server
  these server knows the IP address of the callee)
• Address Format
• IPv4 address sip bob_at_201.23.45.78
• Email Address sip jiri_at_uwaterloo.ca
• Phone number sipbob_at_408-864-8900
• Non-SIP URIs can be used as well (mailto,
  http,)

4
Tracking the callee
callee
Caller
Proxy Server
Registrar
INVITE
Lookup
Reply
INVITE
OK
OK
ACK
ACK
Audio
BYE
5
Functional Requirements

• Registration scenario
• First time registration ( supply name, address,
  other information)
• Client profile updating
• User information (forwarding/blocking list,
  billing information etc. can change during a SIP
  session)
• Operation scenario
• Call without forwarding or blocking
• Call with forwarding list
• Call with blocking
• Calculate the bills(by proxy server)
• Pathological scenario
• Non-existent callee
• Caller crashes during a SIP session
• Proxy server crashes