Cisco Systems 188 Manual De Usuario
D-7
Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (SIP)
OL-3410-01
Appendix D SIP Call Flows
Call Flow Scenarios for Successful Calls
Table D-5
Action Descriptions
Step
Action
Description
Step 1
INVITE—Cisco ATA A to SIP server
Cisco ATA A sends a call session INVITE request to the SIP
server to pass on to Cisco ATA B.
server to pass on to Cisco ATA B.
Step 2
100 Trying—SIP server to Cisco ATA A
SIP server returns a 100 trying message, indicating that the
INVITE request has been received.
INVITE request has been received.
Step 3
INVITE—SIP server to Cisco ATA B
SIP server sends the call session INVITE request to Cisco ATA B.
Step 4
100 Trying—Cisco ATA B to SIP server
Cisco ATA B returns a 100 trying message indicating that the
INVITE request has been received.
INVITE request has been received.
Step 5
180 Ringing—Cisco ATA B to SIP server
Cisco ATA B sends a 180 ringing response to the SIP server to
pass on to Cisco ATA A.
pass on to Cisco ATA A.
Step 6
180 Ringing—SIP server to Cisco ATA A
SIP server sends the 180 ringing response to Cisco ATA A.
Step 7
200 OK—Cisco ATA B to SIP server
Cisco ATA B sends a 200 OK message to the SIP server
indicating that a connection has been established.
indicating that a connection has been established.
Step 8
200 OK—SIP server to Cisco ATA A
SIP server passes the 200 OK message to Cisco ATA A.
Step 9
ACK—Cisco ATA A to SIP server
Cisco ATA A sends acknowledgement of the 200 OK response to
the SIP server to pass on to Cisco ATA B.
the SIP server to pass on to Cisco ATA B.
Step 10
ACK—SIP server to Cisco ATA B
SIP server passes ACK response to Cisco ATA B.
A two-way voice path is established between Cisco ATA A and Cisco ATA B.
Step 11
BYE—Cisco ATA A to SIP server
Cisco ATA A terminates the call session and sends a BYE request
to the SIP server indicating that Cisco ATA A wants to terminate
the call.
to the SIP server indicating that Cisco ATA A wants to terminate
the call.
Step 12
100 Trying—SIP server to Cisco ATA A
SIP server returns a 100 trying message indicating that the BYE
request has been received.
request has been received.
Step 13
BYE—SIP server to Cisco ATA B
SIP server passes the BYE request to Cisco ATA B.
Step 14
200 OK—Cisco ATA B to SIP server
Cisco ATA B sends a 200 OK message to the SIP server
indicating that Cisco ATA B has received the BYE request.
indicating that Cisco ATA B has received the BYE request.
Step 15
200 OK—SIP server to Cisco ATA A
SIP server passes the BYE request to Cisco ATA A.