A SIP-ISDN Gateway

1
A SIP-ISDN Gateway

• Hans Nilsson
• CSLab
• Ericsson Utvecklings AB
• hans_at_erix.ericsson.se

2
What is SIP ?

• Session Initiation Protocol, RFC 2345
• Initiating, Changing and Terminating Multimedia
  conferences (IP Telephony)
• Lightweight
• Textbased Looks like HTTP
• UDP (TCP)

3
Future of SIP?

• Easy to implement gt many small companies
• Mail servers, HTTP Servers, SIP servers
• hans_at_cslab.ericsson.se
• siphans_at_cslab.ericsson.se
• Web integration Services on web pages
• Click-to-dial

4
SIP, Simple Example
Audio, video, ...
5
SIP Redirect Server Example
6
SIP, Other Example
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What is a Gateway?
Audio
8
SIP/ISDN Gateway
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SIP - ISDN
State machine
SIP stack
SIP stack
ISDN stack
10
Erlang code sizesin number of source lines
11
SIP/ISDN Gateway - realisation
SwitchBoard
12
Why Erlang/OTP?
13
Some characteristics
http//www.erlang.org/white_paper.html

• Concurrency
• lightweight processes
• Distribution
• transparent message passing
• Robustness
• node fail-over
• process monitoring
• Soft real-time

• Hot code upgrade
• External interfaces
• Components/Libraries
• Mnesia
• SASL
• SNMP
• Inets
• GS
• ...

14
Users
15
Mobility Server VoIP Prototype Configuration
DECT
RE
PLMN
PTN
H.323
SWB
H.323
SIP
PSTN
IPI
TNI
Wireless LAN
IP
NT Server Mobility Server
ISDN
SIP
H.323
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Mobility Server VoIP Prototype Objectives

• Show Inter-operability between IP Terminals
  and DECT Terminals or PSTN
• Identify effects from implementing existing
  Mobility Server services over VoIP
• Create qualified arguments on SIP versus H.323
  for the Mobility Server product

17
The Future
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FutureWork, work, work...

• Standard MG protocol (MGCP,)
• Less prototypish -)
• Administration
• SNMP
• HTTP/CGI
• Connect to Ericsson Phone Network

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Redundancy and Capacity
SIP
Eddie