Note The term Cisco ATA is used throughout this manual to refer to both the Cisco ATA 186 and the Cisco ATA 188, unless differences between the Cisco ATA 186 and Cisco ATA 188 are explicitly stated.
Supported H.323 Messages
The Cisco ATA supports the following H.323 request methods:
•Request—When registering with an H.323 gatekeeper or Gateway, an individual H.323 endpoint must begin the process by sending a request message.
•Confirm—H.323 gatekeepers and Gateways authorize individual H.323 endpoints to access and send data over the H.323 network with explicit confirmation messages.
•Reject—In the event that an H.323 gatekeeper or Gateway in unable to grant access permission to an H.323 endpoint, a rejection message is sent and call setup is halted.
•Setup—Once access to the H.323 network has been granted, H.323 components contact remote H.323 components via setup messages, initiating two-way voice, video, or data communication.
•Proceeding—When a remote H.323 component acknowledges receipt of call initiation information and agrees to perform necessary subsequent setup for two-way voice, video, or data communication, it responds with a proceeding message.
•Alerting—When a remote H.323 endpoint has begun to notify the called party of an incoming call (the phone begins to ring at the far end), an alerting message is sent back to the calling party.
•Connect—When the called party answers the call (the phone goes off hook), the remote H.323 endpoint transmits a connecting message notifying the calling party that two-way communication is ready to commence.
H.323 Signaling Scenarios
This section describes call flows for the following scenarios:
H.323 Endpoint-to-Endpoint Call Setup with a Common Gatekeeper
Figure D-2 illustrates a Cisco ATA initiating a connection to another Cisco ATA that is registered with the same H.323 gatekeeper. This scenario features registration with no authentication.
Note This scenario assumes that the H.323 configuration employs Slow Start Signaling with tunneling capability.
Figure D-2 H.323 Endpoint-to-Endpoint Call Setup with a Common Gatekeeper
Table D-3 Action Descriptions
Step
Action
Description
1.
Local Admission Request (ARQ)—Local H.323 endpoint to H.323 gatekeeper
Cisco ATA sends a local ARQ message to the H.323 gatekeeper seeking authorization to place a call over the H.323 network.
2.
Local Admission Confirm (ACF) or Admission Reject (ARJ)—H.323 gatekeeper to the local H.323 endpoint
H.323 gatekeeper returns a ACF or ARJ message, indicating whether or not the responding gatekeeper is going to allow the Cisco ATA device access to the network.
3.
Open TCP Channel for Q.931 messaging
TCP port 1720 is opened, making way for the forward and reverse flow of Q.931 signaling messages between the H.323 endpoints.
4.
Q.931 Call Setup—Local H.323 endpoint to remote H.323 endpoint
Call setup initiates from the local H.323 endpoint.
5.
Q.931 Call Proceeding—Remote H.323 endpoint to local H.323 endpoint
Remote Admission Request (ARQ)—Remote Cisco ATA to H.323 gatekeeper
(Somewhat simultaneous, chronologically, to call setup and call proceeding) remote H.323 endpoint contacts the common H.323 gatekeeper, seeking authorization to complete the two-way H.323 network call.
7.
Remote Admission Confirm (ACF) or Admission Reject (ARJ)—H.323 gatekeeper to the remote Cisco ATA
H.323 gatekeeper returns a ACF or ARJ message, indicating whether or not the responding gatekeeper is going to allow the Cisco ATA device access to the network.
8.
Q.931 Alerting—Remote H.323 endpoint to local H.323 endpoint
Status message is sent to calling H.323 endpoint advising that the called party has been notified (phone ringing).
9.
Q.931 Connect—Remote H.323 endpoint to local H.323 endpoint
Status message is sent to calling H.323 endpoint advising that the called party has answered the call (phone off hook).
10.
Open TCP Channel for H.245
Dynamically assigned TCP port is opened on both the local and remote H.323 endpoints, allowing for subsequent call setup activities (transmission and reception capability exchange, master-slave relationship determination, and so on).
11.
H.245 Terminal Capabilities
Various endpoint transmission and reception capabilities defining operation of voice, video, and data are exchanged and acknowledged to ensure consistent, reliable two-way communication between endpoints.
12.
H.245 Terminal Capabilities
13.
H.245 Terminal Capabilities
14.
H.245 Terminal Capabilities
15.
Exchange of Master-Slave Determination Messages—Remote H.323 endpoint to local H.323 endpoint
Determines master and slave assignments between H.323 endpoints.
16.
H.245 Open Audio Logical Channel—Local H.323 endpoint to remote H.323 endpoint
Before actual transmission or reception of voice, video, or data, notification that the primary logical channel for the local H.323 endpoint has been opened, ensuring clear two-way communication.
17.
H.245 Open Audio Logical Channel Acknowledgement—Remote H.323 endpoint to local H.323 endpoint
Remote H.323 endpoint acknowledges readiness.
18.
H.245 Open Audio Logical Channel—Remote H.323 endpoint to local H.323 endpoint
Before actual transmission or reception of voice, video, or data, notification that the primary logical channel for the remote H.323 endpoint has been opened, ensuring clear two-way communication.
19.
H.245 Open Audio Logical Channel Acknowledgement—Local H.323 endpoint to remote H.323 endpoint
Local H.323 endpoint acknowledges readiness.
20.
Bi-Directional Audio with Transcoding in the Endpoints
Two-way communication ensues between endpoints over the H.323 network.
data '0200000028000000000000001B00000081384274...'H
}
}
}
4.
value ARQnonStandardInfo ::=
{
sourceAlias
{
}
sourceExtAlias
{
}
displayInformationElement "Firstname Lastname"
interfaceSpecificBillingId "FXS 1/1/0"
}
5.
value RasMessage ::= admissionRequest :
{
requestSeqNum 61358
callType pointToPoint :NULL
callModel direct :NULL
endpointIdentifier {"814EE09C0000001A"}
destinationInfo
{
e164 :"6661111"
}
srcInfo
{
h323-ID :{"Firstname Lastname"}
}
srcCallSignalAddress ipAddress :
{
ip 'C0A80209'H
port 4568
}
bandWidth 640
callReferenceValue 215
nonStandardData
{
nonStandardIdentifier h221NonStandard :
{
t35CountryCode 181
t35Extension 0
manufacturerCode 18
}
data '8000000860132246697273746E616D65204C6173...'H
}
conferenceID '2E9B85298E88D611AD4600A0CC5C89F1'H
activeMC FALSE
answerCall TRUE
canMapAlias TRUE
callIdentifier
{
guid '2D9B85298E88D611AD4600A0CC5C89F1'H
}
willSupplyUUIEs FALSE
}
6.
value RasMessage ::= admissionConfirm :
{
requestSeqNum 61358
bandWidth 1
callModel direct :NULL
destCallSignalAddress ipAddress :
{
ip 'C0A80363'H
port 1720
}
irrFrequency 240
willRespondToIRR FALSE
uuiesRequested
{
setup FALSE
callProceeding FALSE
connect FALSE
alerting FALSE
information FALSE
releaseComplete FALSE
facility FALSE
progress FALSE
empty FALSE
}
}
7.
value H323_UserInformation ::=
{
h323-uu-pdu
{
h323-message-body callProceeding :
{
protocolIdentifier { 0 0 8 2250 0 2 }
destinationInfo
{
mc FALSE
undefinedNode FALSE
}
h245Address ipAddress :
{
ip 'C0A80363'H
port 11201
}
callIdentifier
{
guid '2D9B85298E88D611AD4600A0CC5C89F1'H
}
}
h245Tunneling FALSE
}
}
8.
value H323_UU_NonStdInfo ::=
{
version 16
protoParam qsigNonStdInfo :
{
iei 30
rawMesg '1E028188'H
}
}
9.
value H323_UserInformation ::=
{
h323-uu-pdu
{
h323-message-body progress :
{
protocolIdentifier { 0 0 8 2250 0 2 }
destinationInfo
{
mc FALSE
undefinedNode FALSE
}
h245Address ipAddress :
{
ip 'C0A80363'H
port 11201
}
callIdentifier
{
guid '2D9B85298E88D611AD4600A0CC5C89F1'H
}
}
h245Tunneling FALSE
nonStandardControl
{
{
nonStandardIdentifier h221NonStandard :
{
t35CountryCode 181
t35Extension 0
manufacturerCode 18
}
data '60011000011E041E028188'H
}
}
}
}
10.
value H323_UU_NonStdInfo ::=
{
version 0
progIndParam progIndIEinfo :
{
progIndIE '00000002'H
}
}
11.
value H323_UserInformation ::=
{
h323-uu-pdu
{
h323-message-body connect :
{
protocolIdentifier { 0 0 8 2250 0 2 }
h245Address ipAddress :
{
ip 'C0A80363'H
port 11201
}
destinationInfo
{
gateway
{
protocol
{
voice :
{
supportedPrefixes
{
{
prefix e164 :"1#"
}
}
}
}
}
mc FALSE
undefinedNode FALSE
}
conferenceID '2E9B85298E88D611AD4600A0CC5C89F1'H
callIdentifier
{
guid '2D9B85298E88D611AD4600A0CC5C89F1'H
}
}
h245Tunneling FALSE
nonStandardControl
{
{
nonStandardIdentifier h221NonStandard :
{
t35CountryCode 181
t35Extension 0
manufacturerCode 18
}
data 'C00100028006000400000002'H
}
}
}
}
12.
value IRRperCallnonStandardInfo ::=
{
startTime 1024959117
}
13.
value RasMessage ::= infoRequestResponse :
{
requestSeqNum 61359
endpointType
{
gateway
{
protocol
{
voice :
{
supportedPrefixes
{
{
prefix e164 :"1#"
}
}
}
}
}
mc FALSE
undefinedNode FALSE
}
endpointIdentifier {"814EE09C0000001A"}
rasAddress ipAddress :
{
ip 'C0A80363'H
port 49450
}
callSignalAddress
{
ipAddress :
{
ip 'C0A80363'H
port 1720
}
}
endpointAlias
{
e164 :"6661111",
e164 :"6663333",
h323-ID :{"zonetwo"}
}
perCallInfo
{
{
nonStandardData
{
nonStandardIdentifier h221NonStandard :
{
t35CountryCode 181
t35Extension 0
manufacturerCode 18
}
data '703D17A28D'H
}
callReferenceValue 215
conferenceID '2E9B85298E88D611AD4600A0CC5C89F1'H
h245
{
}
callSignaling
{
}
callType pointToPoint :NULL
bandWidth 1
callModel direct :NULL
callIdentifier
{
guid '2D9B85298E88D611AD4600A0CC5C89F1'H
}
}
}
needResponse FALSE
}
14.
value H323_UserInformation ::=
{
h323-uu-pdu
{
h323-message-body releaseComplete :
{
protocolIdentifier { 0 0 8 2250 0 2 }
reason undefinedReason :NULL
callIdentifier
{
guid '2D9B85298E88D611AD4600A0CC5C89F1'H
}
}
}
}
15.
value RasMessage ::= disengageRequest :
{
requestSeqNum 61360
endpointIdentifier {"814EE09C0000001A"}
conferenceID '2E9B85298E88D611AD4600A0CC5C89F1'H
callReferenceValue 215
disengageReason normalDrop :NULL
callIdentifier
{
guid '2D9B85298E88D611AD4600A0CC5C89F1'H
}
answeredCall TRUE
}
16.
value RasMessage ::= disengageConfirm :
{
requestSeqNum 61360
}
17.
value RasMessage ::= registrationRequest :
{
requestSeqNum 61361
protocolIdentifier { 0 0 8 2250 0 2 }
discoveryComplete FALSE
callSignalAddress
{
}
rasAddress
{
ipAddress :
{
ip 'C0A80363'H
port 49450
}
}
terminalType
{
mc FALSE
undefinedNode FALSE
}
gatekeeperIdentifier {"zonetwo"}
endpointVendor
{
vendor
{
t35CountryCode 181
t35Extension 0
manufacturerCode 18
}
}
timeToLive 60
keepAlive TRUE
endpointIdentifier {"814EE09C0000001A"}
willSupplyUUIEs FALSE
}
18.
value RasMessage ::= registrationConfirm :
{
requestSeqNum 61361
protocolIdentifier { 0 0 8 2250 0 2 }
callSignalAddress
{
}
gatekeeperIdentifier {"zonetwo"}
endpointIdentifier {"814EE09C0000001A"}
alternateGatekeeper
{
}
timeToLive 60
willRespondToIRR FALSE
}
H.323 Call Setup from H.323 Network to Circuit Switched Network
Figure D-3 illustrates a Cisco ATA initiating a connection to a Circuit Switched Network (CSN) or Public Switched Telephone Network (PSTN) Gateway router through its local H.323 gatekeeper.
Note This scenario assumes that the H.323 configuration employs Fast Start Signaling with tunneling capability.
Figure D-3 H.323 Call Setup from H.323 Network to Circuit Switched Network
Table D-5 Action Descriptions
Step
Action
Description
1.
Local Admission Request (ARQ)—Local endpoint to H.323 gatekeeper
Cisco ATA sends a local ARQ message to the H.323 gatekeeper seeking authorization to place a call over the H.323 network.
2.
Local Admission Confirm (ACF) or Admission Reject (ARJ)—H.323 gatekeeper to the local endpoint
H.323 gatekeeper returns a ACF or ARJ message, indicating whether or not the responding gatekeeper is going to allow the Cisco ATA device access to the network.
3.
Open TCP Channel for Q.931 messaging
TCP port 1720 is opened, making way for the forward and reverse flow of Q.931 signaling messages between the H.323 endpoint and the CSN/PSTN Gateway.
4.
Q.931 Call Setup—Local H.323 endpoint to remote H.323 endpoint
Call setup initiates from the local H.323 endpoint.
5.
Q.931 Call Proceeding—Remote H.323 endpoint to local H.323 endpoint
Gateway acknowledges call setup initiation.
6.
Gateway Admission Request (ARQ)—SCN/PSTN Gateway to H.323 gatekeeper
(Somewhat simultaneous, chronologically, to call setup and call proceeding) Gateway contacts the common H.323 gatekeeper, seeking authorization to complete the two-way H.323 network-to-CSN/PSTN Gateway call.
7.
Gateway Admission Confirm (ACF) or Admission Reject (ARJ)—H.323 gatekeeper to CSN/PSTN Gateway
H.323 gatekeeper returns a ACF or ARJ message, indicating whether or not the responding gatekeeper is going to allow the Gateway access to the network.
8.
Q.931 Alerting—Gateway endpoint to local H.323 endpoint
Status message is sent to calling H.323 endpoint advising that the called party has been notified (phone ringing).
9.
Q.931 Connect—Gateway to local H.323 endpoint
Status message is sent to calling H.323 endpoint advising that the called party has answered the call (phone off hook).
10.
Open TCP Channel for H.245
Dynamically assigned TCP port is opened on both the local H.323 endpoint and the Gateway, allowing for subsequent call setup activities (transmission and reception capability exchange, master-slave relationship determination, and so on).
11.
H.245 Terminal Capabilities
Various endpoint transmission and reception capabilities defining operation of voice, video, and data are exchanged and acknowledged to ensure consistent, reliable two-way communication between the H.323 endpoint and the Gateway.
12.
H.245 Terminal Capabilities
13.
H.245 Terminal Capabilities
14.
H.245 Terminal Capabilities
15.
Exchange of Master-Slave Determination Messages—Remote H.323 endpoint to local H.323 endpoint
Determines master and slave assignments between the H.323 endpoint and the Gateway.
16.
H.245 Open Audio Logical Channel—Local H.323 endpoint to remote H.323 endpoint
Before actual transmission or reception of voice, video, or data, notification that the primary logical channel for the local H.323 endpoint has been opened, ensuring clear two-way communication.
17.
H.245 Open Audio Logical Channel Acknowledgement—Remote H.323 endpoint to local H.323 endpoint
Gateway acknowledges readiness.
18.
H.245 Open Audio Logical Channel—Remote H.323 endpoint to local H.323 endpoint
Before actual transmission or reception of voice, video, or data, notification that the primary logical channel for the Gateway has been opened, ensuring clear two-way communication.
19.
H.245 Open Audio Logical Channel Acknowledgement—Local H.323 endpoint to remote H.323 endpoint
Local H.323 endpoint acknowledges readiness.
20.
Bi-Directional Audio with Transcoding Between Endpoint and Gateway
Two-way communication ensues between the local H.323 endpoint and the CSN/PSTN Gateway.
Feedback
The term Cisco ATA is used throughout this manual to refer to both the Cisco ATA 186 and the Cisco ATA 188, unless differences between the Cisco ATA 186 and Cisco ATA 188 are explicitly stated.
