Cisco ATA-186 Administrator's Manual page 189

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