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

INVITEhelen@ucla.edu

Location Server

john@hol.gr

INVITE helen@ee.ucla.edu

ACKReply helen@ee.ucla.edu

helen@ee.ucla.edu

Query

SIP Server

4

Distributed Name Resolution System

Database Records User Description as a list of attribute value

pairs Database maintenance information

Record No

Maintenance InformationAttribute value pair list

a=1 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

Find all Friends

A

B D

Query Reply

Query

C

Friend

7

Application Level Forwarding

Send(Hello) to all Friends

A

B D Friends are at C

Registration

Forwarding

Friends are at B

Friends are at A

C

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