There are two ways to send a SIP message with the SIP for NCC API:
Using SIP for NCC API functions that send SIP messages automatically.
Use nccSendCallMessage to send SIP messages that cannot be sent by using other NCC functions. When you use nccSendCallMessage, you must include values for SIP information elements.
The following table lists the SIP for NCC API functions along with the SIP commands and responses they are associated with:
Function |
SIP method |
Response code |
nccAcceptCall |
INVITE |
180 |
nccAcknowledgeCall |
ACK |
request |
INVITE |
100 |
|
nccAnswerCall |
INVITE |
200 |
nccAutomaticTransfer |
REFER |
request |
nccDisconnectCall |
BYE or CANCEL |
request |
nccHandleTransferRequest |
REFER |
202 or 501 |
nccHoldCall |
INVITE |
request |
nccPlaceCall |
INVITE |
request |
nccRejectCall |
INVITE |
600, 603, 604, or 606 |
nccRetrieveCall |
INVITE |
request |
nccSendCapabilityQuery |
REQUEST |
200 |
nccSendCapabilityResponse |
OPTIONS |
200 |
nccSendPrack |
PRACK |
request |
nccSendPrackResponse |
PRACK |
200 |
nccTransferCall |
REFER |
request |
For example, to send a SIP INVITE request when you are placing a call, invoke nccPlaceCall. The nccPlaceCall function generates a SIP INVITE request and sends it automatically.
Note: This method of sending a SIP message is compatible with SIP for NCC 1.0 functionality.
Use nccSendCallMessage to send SIP messages that cannot be sent using the NCC functions listed in the previous subsection. When you use nccSendCallMessage, include the following information elements with the function:
The following table lists the SIP methods and response codes that you can use with nccSendCallMessage:
SIP method |
Response codes |
Notes |
INVITE used to initiate a dialog |
1xx |
|
INVITE issued in the context of a dialog (also called a re-INVITE) |
request |
Used in the connected state only. |
1xx – 6xx |
Used in the connected state only. |
|
ACK |
Used in the connected state only. The ACK message may be generated automatically, depending on the server configuration. |
For example, to send a SIP INVITE request in the context of a dialog (a re-INVITE request), invoke nccSendCallMessage with the following information element values:
SIP_IE_METHOD = INVITE
SIP_IE_BODY = SDP offer for reINVITE