Dialogic 05-2239-009 User Manual

Dialogic

Global Call IP Technology Guide — November 2007

Dialogic Corporation

IP Call Scenarios

3.1.1

Basic Call Setup When Using H.323 or SIP

Figure 8 shows the basic call setup sequence when using H.323 or SIP.

Notes: 1. This figure assumes that the network and media channels are already open and a media channel

with the appropriate media capabilities is attached to the network channel. See

, on page 476 for information on opening and attaching network

and media devices and

detailed information on the specification of the destination address etc.

2. Only H.225.0 (Q.931) messages are shown in the sequence below. H.245 messages were omitted

in the interest of simplification.

3. The destination address must be a valid address that can be translated by the remote node.

Figure 8. Basic Call Setup When Using H.323 or SIP

Application

gc_MakeCall( )

SIP: INVITE

GlobalCall

gc_WaitCall( )

GCEV_DIALING

GCEV_DETECTED

GCEV_OFFERED

gc_CallAck

(GCACK_SERVICE_PROC)

SIP: 100 (Trying)

GCEV_PROCEEDING

GCEV_CALLPROC

gc_AcceptCall( )

SIP: 180 (Ringing)

GCEV_ALERTING

GCEV_ACCEPT

gc_AnswerCall( )

GCEV_ANSWERED

SIP: 200 (OK)

GCEV_CONNECTED

SIP: ACK

H.323: Q.931 Proceeding

H.323: Q.931 Connected

H.323: Q.931 Alerting

H.323: Q.931 Setup