AndmesideIRT 0030

loeng 11 16. nov. 2005

Avo Ots

telekommunikatsiooni õppetoolraadio- ja sidetehnika instituut

avots@lr.ttu.ee

Kokkuühendamine

ATM Networks

IWF

PSTN/ISDN Rec. Q.2931, PNNI

Frame Relay

Networks

IP-based Networks

Rec. Y.1310

IETF RFCs

IWF

IWF

Rec. I.555Rec. I.580

Rec. Q.931

ATM OSF & NM, M series Rec.

SNMP based

FR OSF & NM

PSTN/ISDN

IWF

SS7 Network

Rec. I.580Rec. Q.700 series

Wireless access

IWF

Võrkude ühiskasutus

Ethernet

AdhocNetwork

AdhocNetwork

cdma2000 1xoperator 1

cdma2000 1xoperator 2

GPRS

Edge

WLAN

WebServer

IPNetwork

IPNetwork

Võrguliikluse jaotus

Time slots

Arr

ival

rat

e

tts

T

C

Temporarilybuffered

What is SIP?

• Session Initiation Protocol protocol that establishes, manages (multimedia) sessions– also used for IM, presence & event

notification– uses SDP to describe multimedia sessions

• Standardized by IETF, 3GPP (for 3G wireless), PacketCable

Building Applications On Sip

• Applications for example instant messaging can be built on SIP. Such applications are quick to write with any SIP toolkit and are easily extensible.

Useragent

Proxyserver

Proxyserver

User agentACK

OK

invite invite

OK

ACK

invite

OK

ACK

LDAPserver

LDAP server

lmn@tech.net--> 138.47.19.103

SIP trapezoid

SIP trapezoid

outbound proxy

a@foo.com: 128.59.16.1

registrar

Session mobility• Walk into office, switch

from cell phone to desk phone– call transfer problem SIP

REFER• related problem: split

session across end devices– e.g., wall display + desk

phone + PC for collaborative application

– assume devices (or stand-ins) are SIP-enabled

– third-party call control

Why Phone NUMBERS?• Users should not be burdened with device addresses,

when it’s people they really care about• Addresses should be mnemonic and empower

enterprises to manage the identities of their userssip:dbaron@mit.edu

• It’s time to put E.164 phonenumbers behind us!

• A.G. Bell did not say:

“+1-617-252-1232, come here. I need you!”

SIPProxy

DNSSIP-PBXGateway

PBX

INVITE (sip:bob@bigu.edu)

INVITE(sip:12345@gw.bigu.edu)

DNS SRV query sip.udp.bigu.edu

telephoneNumberwhere mail=”bob”

PRI / CASbigu.edu

CampusDirectory

SIP User Agent

Bob's Phone

SIP.edu Architecture (Phase 1)

DNS

INVITE (sip:bob@bigu.edu)DNS SRV query

sip.udp.bigu.edu

bigu.edu

SIP User Agent

SIP.edu Architecture (Phase 2)

locationDB

If Bob has registered, ring his SIP phone; Else, call his extension through the PBX.

REGISTER(Contact: 207.75.164.131)

INVITE (sip:bob@207.75.164.131)

SIPProxy

SIPRegistrar

Bob's SIP Phone

PBX PSTN

SIP/PRIGateway

SIP.edu Configuration

SIP Server

Campus Network

Internet

DNS Server

LDAP Server

PBX PSTN

SIP/PRIGateway

DNS SRV Lookup

SIP Server

Internet

DNS Server

DNS SRV

LDAP Server

Campus Network

PBX PSTN

SIP/PRIGateway

SIP INVITE

SIP Server

Internet

DNS Server

SIP

LDAP Server

Campus Network

PBX PSTN

SIP/PRIGateway

LDAP Lookup

SIP Server

Internet

DNS Server

LDAP

LDAP Server

Campus Network

PBX PSTN

SIP/PRIGateway

Call Sent to PBX Gateway

SIP Server

Internet

DNS Server

SIP

LDAP Server

Campus Network

PBX PSTN

SIP/PRIGateway

Media Stream via Gateway to PBX

SIP Server

Internet

DNS Server

RTP

LDAP Server

Campus Network

PBX PSTN

SIP/PRIGateway

SIP.edu Configuration

SIP Server

Internet

DNS Server

LDAP Server

Campus Network

PBX PSTN

SIP/PRIGateway

SIP to PBX and PSTN Calling

SIP Server

Internet

DNS Server

LDAP Server

Campus Network

PBX PSTN

SIP/PRIGateway

PBX and PSTN to SIP Calling

SIP Server

Internet

DNS Server

LDAP Server

Campus Network