Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator's Guide (SIP) (2.15, Rev B0)
SIP Call Flows
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SIP Call Flows

Table Of Contents

SIP Call Flows

Supported SIP Request Methods

Call Flow Scenarios for Successful Calls

Cisco ATA-to-SIP Server—Registration without Authentication

Cisco ATA-to-SIP Server—Registration with Authentication

Cisco ATA-to-Cisco ATA—Basic SIP to SIP Call without Authentication

Cisco ATA-to-Cisco ATA—Basic SIP to SIP Call with Authentication


SIP Call Flows


This section describes some basic call flows for the Cisco ATA:

Supported SIP Request Methods

Call Flow Scenarios for Successful Calls


Note The term Cisco ATA refers to both the Cisco ATA 186 and the Cisco ATA 188, unless otherwise stated.


Supported SIP Request Methods

The Cisco ATA supports the following SIP request methods:

INVITE—Indicates a user or service is being invited to participate in a call session.

ACK—Confirms that the client has received a final response to an INVITE request.

BYE—Terminates a call and can be sent by either the caller or the callee.

CANCEL—Cancels any pending searches but does not terminate a call that has already been accepted.

REGISTER—Registers the address listed in the To header field with a SIP proxy.

NOTIFY—Notifies the user of the status of a transfer using REFER. Also used for remote reset.

OPTIONS

The following types of responses are used by SIP and generated by the Cisco SIP gateway:

SIP 1xx—Informational responses

SIP 2xx—Successful responses

SIP 3xx—Redirection responses

SIP 4xx—Client Failure responses

SIP 5xx—Server Failure responses

SIP 6xx—Global Failure responses

Call Flow Scenarios for Successful Calls

This section describes call flows for the following scenarios:

Cisco ATA-to-SIP Server—Registration without Authentication

Cisco ATA-to-SIP Server—Registration with Authentication

Cisco ATA-to-Cisco ATA—Basic SIP to SIP Call without Authentication

Cisco ATA-to-Cisco ATA—Basic SIP to SIP Call with Authentication

Each of the call flows includes a call diagram, action descriptions table, and a sample log file.

Cisco ATA-to-SIP Server—Registration without Authentication

Figure D-1 illustrates the Cisco ATA registering with the SIP server. Authentication is not required for registration.

The call flow is as follows:

1. Cisco ATA requests registration.

2. Registration is completed.

Figure D-1 Cisco ATA-to-SIP Server—Registration without Authentication

Table D-1 Action Descriptions

Step
Action
Description

Step 1 

REGISTER—Cisco ATA to SIP server

Cisco ATA sends a REGISTER message to the SIP server to register the address in the To header field.

Step 2 

100 Trying—SIP Server to Cisco ATA

SIP server returns a 100 Trying message, indicating that the REGISTER request has been received.

Step 3 

200 OK—SIP server to Cisco ATA

SIP server returns a final 200 OK response, confirming that registration is complete.

Table D-2 Log Listings 

1.

REGISTER sip:192.168.2.97 SIP/2.0 
Via: SIP/2.0/UDP 192.168.2.194 
From: <sip:9301@192.168.2.97;user=phone> 
To: <sip:9301@192.168.2.97;user=phone> 
Call-ID: 88397253@192.168.2.194 
CSeq: 1 REGISTER 
Contact: <sip:9301@192.168.2.194;user=phone;transport=udp>;expires=3600 
User-Agent; Cisco ATA v2.10 ata186 (0705a) 
Content-Length: 0

2.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 192.168.2.194 
Call-ID: 88397253@192.168.2.194 
From: <sip:9301@192.168.2.97;user=phone> 
To: <sip:9301@192.168.2.97;user=phone> 
CSeq: 1 REGISTER 
Content-Length: 0

3.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.2.194 
Call-ID: 88397253@192.168.2.194 
From: <sip:9301@192.168.2.97;user=phone> 
To: <sip:9301@192.168.2.97;user=phone> 
CSeq: 1 REGISTER 
Contact: <sip:9301@192.168.2.194;user=phone;transport=udp>;expires="tue, 23 Oct 2001 14:24:57 GMT" 
Expires: 3600 
Content-Length: 0

Cisco ATA-to-SIP Server—Registration with Authentication

Figure D-2 illustrates the Cisco ATA registering with the SIP server. Authentication is required for registration.

The call flow is as follows:

1. Cisco ATA requests registration.

2. SIP server requests authentication credential.

3. Authentication is received and registration is completed.

Figure D-2 Cisco ATA-to-SIP Server—Registration with Authentication

Table D-3

Step
Action
Description

Step 1 

REGISTER—Cisco ATA to SIP server

Cisco ATA sends a REGISTER message to the SIP server to register the address in the To header field.

Step 2 

100 Trying—SIP server to Cisco ATA

SIP server returns a 100 trying message, indicating that the REGISTER request has been received.

Step 3 

407 Proxy authentication required— SIP server to Cisco ATA

SIP server returns a request for authentication.

Step 4 

REGISTER—Cisco ATA to SIP server

Cisco ATA attempts to register using its authentication credential.

Step 5 

100 Trying—SIP server to Cisco ATA

SIP server returns a 100 trying message, indicating that the new REGISTER request has been received.

Step 6 

200 OK—SIP server to Cisco ATA

SIP server returns a final 200 OK response, confirming that the authentication credential has been verified and registration is complete.

Action Descriptions

Table D-4 Log Listings 

1.

REGISTER sip:192.168.2.81 SIP/2.0 
Via: SIP/2.0/UDP 192.168.2.194 
From: <sip:9301@192.168.2.81;user=phone> 
To: <sip:9301@192.168.2.81;user=phone> 
Call-ID: 311316842@192.168.2.194 
CSeq: 1 REGISTER 
Contact: <sip:9301@192.168.2.194;user=phone;transport=udp>;expires=3600 
User-Agent; Cisco ATA v2.10 ata186 (0705a) 
Content-Length: 0

2.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 192.168.2.194 
Call-ID: 311316842@192.168.2.194 
From: <sip:9301@192.168.2.81;user=phone> 
To: <sip:9301@192.168.2.81;user=phone> 
CSeq: 1 REGISTER 
Content-Length: 0

3.

SIP/2.0 407 Proxy Authentication Required 
Via: SIP/2.0/UDP 192.168.2.194 
Call-ID:311316842@192.168.2.194 
From: <sip:9301@192.168.2.81;user=phone> 
To: <sip:9301@192.168.2.81;user=phone> 
CSeq: 1 REGISTER 
Proxy-Authenticate: DIGEST realm="CISCO", nonce="3bd5e334" 
Content-Length: 0

4.

REGISTER sip:192.168.2.81 SIP/2.0 
Via: SIP/2.0/UDP 192.168.2.194 
From: <sip:9301@192.168.2.81;user=phone> 
To: <sip:9301@192.168.2.81;user=phone> 
Call-ID: 311316842@192.168.2.194 
CSeq: 2 REGISTER 
Contact: <sip:9301@192.168.2.194;user=phone;transport=udp>;expires=3600 
User-Agent: Cisco ATA v2.10 ata186 (0705a) 
Proxy-Authorization: Digest 
username="9301",realm="CISCO",nonce="3bd5e334",uri="sip:192.168.2.81",response="87ac0afeb08222af706
f9e8b5c566ce2" 
Content-Length: 0

5.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 192.168.2.194 
Call-ID: 311316842@192.168.2.194 
From: <sip:9301@192.168.2.81;user=phone> 
To: <sip:9301@192.168.2.81;user=phone> 
CSeq: 2 REGISTER 
Content-Length: 0

6.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.2.194 
Call-ID: 311316842@192.168.2.194 
From: <sip:9301@192.168.2.81;user=phone> 
To: <sip:9301@192.168.2.81;user=phone> 
CSeq: 2 REGISTER 
Contact: <sip:9301@192.168.2.194;user=phone;transport=udp>;expires="tue, 23 Oct 2001 22:37:56 GMT" 
Expires: 3600 
Content-Length: 0

Cisco ATA-to-Cisco ATA—Basic SIP to SIP Call without Authentication

Figure D-3 illustrates a call from one Cisco ATA to another. Authentication by the SIP server is not required.

The call flow is as follows:

1. Call is established between Cisco ATA A and Cisco ATA B.

2. Call is terminated.

Figure D-3 Cisco ATA-to-Cisco ATA—Basic SIP to SIP Call without Authentication

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.

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.

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.

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.

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.

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.

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.

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.

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.

Step 15 

200 OK—SIP server to Cisco ATA A

SIP server passes the BYE request to Cisco ATA A.

Table D-6 Log Listings 

1.

INVITE sip:9000@192.168.2.97;user=phone SIP/2.0 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone> 
Call-ID: 488337201@192.168.3.175 
CSeq: 1 INVITE 
Contact: <sip:8000@192.168.3.175;user=phone;transport=udp> 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Expires: 300 
Content-Length: 253 
Content-Type: application/sdp
v=0 
o=8000 206154 206154 IN IP4 192.168.3.175 
s=ATA186 Call 
c=IN IP4 192.168.3.175 
t=0 0 
m=audio 10000 RTP/AVP 0 18 8 101 
a=rtpmap:0 PCMU/8000/1 
a=rtpmap:18 G729/8000/1 
a=rtpmap:8 PCMA/8000/1 
a=rtpmap:101 telephone-event/8000 
a=fmtp:101 0-15

2.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 192.168.3.175 
Call-ID: 488337201@192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone> 
CSeq: 1 INVITE 
Content-Length: 0

3.

INVITE sip:9000@192.168.2.194;user=phone SIP/2.0 
Record-Route: <sip:9000@192.168.2.97:5060;user=phone;maddr=192.168.2.97> 
Via: SIP/2.0/UDP 192.168.2.97:5060;branch=140fed6e-f61cbd1a-52f223b1-9beb149a-1 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone> 
Call-ID: 488337201@192.168.3.175 
CSeq: 1 INVITE 
Contact: <sip:8000@192.168.3.175;user=phone;transport=udp> 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Expires: 300 
Content-Length: 253 
Content-Type: application/sdp
v=0 
o=8000 206154 206154 IN IP4 192.168.3.175 
s=ATA186 Call 
c=IN IP4 192.168.3.175 
t=0 0 
m=audio 10000 RTP/AVP 0 18 8 101 
a=rtpmap:0 PCMU/8000/1 
a=rtpmap:18 G729/8000/1 
a=rtpmap:8 PCMA/8000/1 
a=rtpmap:101 telephone-event/8000 
a=fmtp:101 0-15

4.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 192.168.2.97:5060;branch=140fed6e-f61cbd1a-52f223b1-9beb149a-1 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.97:5060;user=phone;maddr=192.168.2.97> 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 1 INVITE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

5.

SIP/2.0 180 Ringing 
Via: SIP/2.0/UDP 192.168.2.97:5060;branch=140fed6e-f61cbd1a-52f223b1-9beb149a-1 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.97:5060;user=phone;maddr=192.168.2.97> 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 1 INVITE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

6.

SIP/2.0 180 Ringing 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.97:5060;user=phone;maddr=192.168.2.97> 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 1 INVITE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

7.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.2.97:5060;branch=140fed6e-f61cbd1a-52f223b1-9beb149a-1 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.97:5060;user=phone;maddr=192.168.2.97 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 1 INVITE 
Contact: <sip:9000@192.168.2.194;user=phone;transport=udp> 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 199 
Content-Type: application/sdp
v=0 
o=9000 206275 206275 IN IP4 192.168.2.194 
s=ATA186 Call 
c=IN IP4 192.168.2.194 
t=0 0 
m=audio 10000 RTP/AVP 0 101 
a=rtpmap:0 PCMU/8000/1 
a=rtpmap:101 telephone-event/8000 
a=fmtp:101 0-15

8.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.97:5060;user=phone;maddr=192.168.2.97 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 1 INVITE 
Contact: <sip:9000@192.168.2.194;user=phone;transport=udp> 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 199 
Content-Type: application/sdp
v=0 
o=9000 206275 206275 IN IP4 192.168.2.194 
s=ATA186 Call 
c=IN IP4 192.168.2.194 
t=0 0 
m=audio 10000 RTP/AVP 0 101 
a=rtpmap:0 PCMU/8000/1 
a=rtpmap:101 telephone-event/8000 
a=fmtp:101 0-15

9.

ACK sip:9000@192.168.2.97;user=phone SIP/2.0 
Route: <sip:9000@192.168.2.194:5060;user=phone;transport=udp> 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 1 ACK 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

10.

ACK sip:9000@192.168.2.194;user=phone SIP/2.0 
Via: SIP/2.0/UDP 192.168.2.97:5060;branch=140fed6e-f61cbd1a-52f223b1-9beb149a- 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 1 ACK 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

11.

BYE sip:9000@192.168.2.97;user=phone SIP/2.0 
Route: <sip:9000@192.168.2.194:5060;user=phone;transport=udp> 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 2 BYE 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

12.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 19.168.3.175 
Call-ID: 488337201@192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
CSeq: 2 BYE 
Content-Length: 0

13.

BYE sip:9000@192.168.2.194;user=phone SIP/2.0 
Via: SIP/2.0/UDP 192.168.2.97:5060;branch=b499b4be-d7995db7-980cd8af-e5ba35f5-1 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 2 BYE 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

14.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.2.97:5060;branch=b499b4be-d7995db7-980cd8af-e5ba35f5-1 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 2 BYE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

15.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.97;user=phone>;tag=2819471139 
To: <sip:9000@192.168.2.97;user=phone>;tag=909616993 
Call-ID: 488337201@192.168.3.175 
CSeq: 2 BYE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

Cisco ATA-to-Cisco ATA—Basic SIP to SIP Call with Authentication

Figure D-4 illustrates a call from one Cisco ATA to another. Authentication by the SIP server is required.

The call flow is as follows:

1. Authentication is requested for call initiated by Cisco ATA A.

2. Call is established between Cisco ATA A and Cisco ATA B.

3. Call is terminated.

Figure D-4 Cisco ATA-to-Cisco ATA—Basic SIP to SIP Call with Authentication

Table D-7 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.

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.

Step 3 

407 Proxy Authentication Required— SIP server to Cisco ATA A

SIP server returns a request for authentication to Cisco ATA A.

Step 4 

ACK—Cisco ATA A to SIP server

Cisco ATA A acknowledges the request for authentication.

Step 5 

INVITE—Cisco ATA A to SIP server

Cisco ATA A sends a call session INVITE request along with authentication credential to the SIP server to pass on to Cisco ATA B.

Step 6 

100 Trying—SIP server to Cisco ATA A

SIP server returns a 100 Trying message, indicating that the INVITE request has been received.

Step 7 

INVITE—SIP server to Cisco ATA B

SIP server sends the call session INVITE request to Cisco ATA B.

Step 8 

100 Trying—Cisco ATA B to SIP server

Cisco ATA B returns a 100 trying message indicating that the INVITE request has been received.

Step 9 

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.

Step 10 

180 Ringing—SIP server to Cisco ATA A

SIP server sends the 180 ringing response to Cisco ATA A.

Step 11 

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.

Step 12 

200 OK—SIP server to Cisco ATA A

SIP server passes the 200 OK message to Cisco ATA A.

Step 13 

ACK—Cisco ATA A to SIP server

Cisco ATA A sends acknowledgment of the 200 OK response to the SIP server to pass on to Cisco ATA B.

Step 14 

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 15 

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.

Step 16 

100 Trying—SIP server to Cisco ATA A

SIP server returns a 100 trying message indicating that the BYE request has been received.

Step 17 

BYE—SIP server to Cisco ATA B

SIP server passes the BYE request to Cisco ATA B.

Step 18 

200 OK—Cisco ATA B to SIP server

Cisco ATA 186 B sends a 200 OK message to the SIP server indicating that Cisco ATA 186 B has received the BYE request.

Step 19 

200 OK—SIP server to Cisco ATA A

SIP server passes the BYE request to Cisco ATA A.

Table D-8 Log Listings 

1.

INVITE sip:9000@192.168.2.81;user=phone SIP/2.0 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone> 
Call-ID: 557188650@192.168.3.175 
CSeq: 1 INVITE 
Contact: <sip:8000@192.168.3.175;user=phone;transport=udp> 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Expires: 300 
Content-Length: 253 
Content-Type: application/sdp
v=0 
o=8000 177731 177731 IN IP4 192.168.3.175 
s=ATA186 Call 
c=IN IP4 192.168.3.175 
t=0 0 
m=audio 10000 RTP/AVP 0 18 8 101 
a=rtpmap:0 PCMU/8000/1 
a=rtpmap:18 G729/8000/1 
a=rtpmap:8 PCMA/8000/1 
a=rtpmap:101 telephone-event/8000 
a=fmtp:101 0-15

2.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 192.168.3.175 
Call-ID: 557188650@192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone> 
CSeq: 1 INVITE 
Content-Length: 0

3.

SIP/2.0 407 Proxy Authentication Required 
Via: SIP/2.0/UDP 192.168.3.175 
Call-ID: 557188650@192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To:<sip:9000@192.168.2.81;user=phone>;tag=600eaef7-7c3a549a 
CSeq: 1 INVITE 
Proxy-Authenticate: DIGEST realm="CISCO", nonce="3bd76584" 
Content-Length: 0

4.

ACK sip:9000@192.168.2.81:5060 SIP/2.0 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To:<sip:9000@192.168.2.81;user=phone>;tag=600eaef7-7c3a549a 
Call-ID: 557188650@192.168.3.175 
CSeq: 1 ACK 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

5.

INVITE sip:9000@192.168.2.81;user=phone SIP/2.0 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone> 
Call-ID: 557188650@192.168.3.175 
CSeq: 2 INVITE 
Contact: <sip:8000@192.168.3.175;user=phone;transport=udp> 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Proxy-Authorization: Digest username="8000",realm="CISCO",nonce="3bd76584", 
uri="sip:9000@192.168.2.81",response="6e91de67ad976997ffac76f0398ef224" 
Expires: 300 
Content-Length: 253 
Content-Type: application/sdp
v=0 
o=8000 177738 177738 IN IP4 192.168.3.175 
s=ATA186 Call 
c=IN IP4 192.168.3.175 
t=0 0 
m=audio 10000 RTP/AVP 0 18 8 101 
a=rtpmap:0 PCMU/8000/1 
a=rtpmap:18 G729/8000/1 
a=rtpmap:8 PCMA/8000/1 
a=rtpmap:101 telephone-event/8000 
a=fmtp:101 0-15

6.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 192.168.3.175 
Call-ID: 557188650@192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone> 
CSeq: 2 INVITE 
Content-Length: 0

7.

INVITE sip:9000@192.168.2.194;user=phone SIP/2.0 
Record-Route: <sip:9000@192.168.2.81:5060;user=phone;maddr=192.168.2.81 
Via: SIP/2.0/UDP 192.168.2.81:5060;branch=c0b3510a-819f9d1a-ea43c345-9604747f-1 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone> 
Call-ID: 557188650@192.168.3.175 
CSeq: 2 INVITE 
Contact: <sip:8000@192.168.3.175;user=phone;transport=udp> 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Proxy-Authorization: Digest username="8000",realm="CISCO",nonce="3bd76584", 
uri="sip:9000@192.168.2.81",response="6e91de67ad976997ffac76f0398ef224" 
Expires: 300 
Content-Length: 253 
Content-Type: application/sdp
v=0 
o=8000 177738 177738 IN IP4 192.168.3.175 
s=ATA186 Call 
c=IN IP4 192.168.3.175 
t=0 0 
m=audio 10000 RTP/AVP 0 18 8 101 
a=rtpmap:0 PCMU/8000/1 
a=rtpmap:18 G729/8000/1 
a=rtpmap:8 PCMA/8000/1 
a=rtpmap:101 telephone-event/8000 
a=fmtp:101 0-15

8.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 192.168.2.81:5060;branch=c0b3510a-819f9d1a-ea43c345-9604747f-1 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.81:5060;user=phone;maddr=192.168.2.81> 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 2 INVITE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

9.

SIP/2.0 180 Ringing 
Via: SIP/2.0/UDP 192.168.2.81:5060;branch=c0b3510a-819f9d1a-ea43c345-9604747f-1 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.81:5060;user=phone;maddr=192.168.2.81> 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 2 INVITE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

10.

SIP/2.0 180 Ringing 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.81:5060;user=phone;maddr=192.168.2.81> 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 2 INVITE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

11.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.2.81:5060;branch=c0b3510a-819f9d1a-ea43c345-9604747f-1 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.81:5060;user=phone;maddr=192.168.2.81 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 2 INVITE 
Contact: <sip:9000@192.168.3.194;user=phone;transport=udp> 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 199 
Content-Type: application/sdp
v=0 
o=9000 179263 179263 IN IP4 192.168.2.194 
s=ATA186 Call 
c=IN IP4 192.168.2.194 
t=0 0 
m=audio 10000 RTP/AVP 0 101 
a=rtpmap:0 PCMU/8000/1 
a=rtpmap:101 telephone-event/8000 
a=fmtp:101 0-15

12.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.3.175 
Record-Route: <sip:9000@192.168.2.81:5060;user=phone;maddr=192.168.2.81 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 2 INVITE 
Contact: <sip:9000@192.168.2.194;user=phone;transport=udp> 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 199 
Content-Type: application/sdp
v=0 
o=9000 179263 179263 IN IP4 192.168.2.194 
s=ATA186 Call 
c=IN IP4 192.168.2.194 
t=0 0 
m=audio 10000 RTP/AVP 0 101 
a=rtpmap:0 PCMU/8000/1 
a=rtpmap:101 telephone-event/8000 
a=fmtp:101 0-15

13.

ACK sip:9000@192.168.2.81;user=phone SIP/2.0 
Route: <sip:9000@192.168.2.194:5060;user=phone;transport=udp> 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 2 ACK 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

14.

ACK sip:9000@192.168.2.194;user=phone SIP/2.0 
Via: SIP/2.0/UDP 192.168.2.81:5060;branch=c0b3510a-819f9d1a-ea43c345-9604747f-1 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 2 ACK 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

15.

BYE sip:9000@192.168.2.81;user=phone SIP/2.0 
Route: <sip:9000@192.168.2.194:5060;user=phone;transport=udp> 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 3 BYE 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

16.

SIP/2.0 100 Trying 
Via: SIP/2.0/UDP 19.168.3.175 
Call-ID: 557188650@192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
CSeq: 3 BYE 
Content-Length: 0

17.

BYE sip:9000@192.168.2.194;user=phone SIP/2.0 
Via: SIP/2.0/UDP 192.168.2.81:5060;branch=424f3898-9ef87cec-82179ac3-50eeb1d3-1 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 3 BYE 
User-Agent: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

18.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.2.81:5060;branch=424f3898-9ef87cec-82179ac3-50eeb1d3-1 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 3 BYE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0

19.

SIP/2.0 200 OK 
Via: SIP/2.0/UDP 192.168.3.175 
From: <sip:8000@192.168.2.81;user=phone>;tag=3515135869 
To: <sip:9000@192.168.2.81;user=phone>;tag=100585329 
Call-ID: 557188650@192.168.3.175 
CSeq: 3 BYE 
Server: Cisco ATA v2.12 ata186 (0928a) 
Content-Length: 0