Attribute Based Addressing for SIP

1
Attribute Based Addressing for SIP

• Vlasios Tsiatsis , Jyh-Cheng Chen , Prathima
  Agrawal and Mani Srivastava
• UCLA Electrical Engineering Department, Los
  Angeles, CA, USA
• Applied Research, Telcordia Technologies, Inc.
• Morristown, NJ, USA
• April 2, 2001

2
Introduction

• Network entities are named either by IP address
  or a fully qualified domain name
• Users like descriptive and contextual names
• e.g. call my friend Bob, call the nearest
  policeman
• Call based and Packet based services in a natural
  way
• e.g. call my friends, send my friends this
  picture

3
Contribution

• Implement an additional user location service for
  SIP ...
• .. as a distributed system of attribute based
  name resolvers

SIP Server
INVITE helen_at_ucla.edu
john_at_hol.gr
Query
Location Server
Reply helen_at_ee.ucla.edu
INVITE helen_at_ee.ucla.edu
ACK
helen_at_ee.ucla.edu
4
Distributed Name Resolution System

• Database Records
• User Description as a list of attribute value
  pairs
• Database maintenance information

• Maintenance Information
• Attribute value pair list
• a1
• name vlasios
• occupation student
• city Seattle

5
Requests/Responses

• Each message is preceded by the requesting user
  identification
• Registration (soft state)
• Signoff
• Description Modification
• Query
• Application Level Forwarding
• Responses in XML form

6
Information/Request Processing

• All requests are scoped
• Currently update requests are replicated to all
  location servers
• Queries like DNS

7
Application Level Forwarding
What is we only wanted to push send messages to
other users ? What is other users have variable
attributes or they move ?
8
Integration with SIP

• Used Columbia SIP client/server implementation
• Added the necessary GUI for SIP client and the
  necessary code for SIP server
• Used the extension mechanism of SIP (Require
  header)
• Registration and Updates in REGISTER requests
• Queries and Application Forwarding in INVITE
  requests

9
Future Work

• Indexing Scheme for Information Processing and
  Distribution (currently replication)
• What happens if a user wants to be found
• by specific users ?
• by specific machines ?
• at some specific time of the day ?
• Push based messaging system

10
Conclusions

• Provide a unified naming system for individuals
  or groups
• Descriptive and natural naming system for IP
  telephony
• Users concentrate on what they want
• Suitable for packet oriented communication