/// <summary>
/// Creates ACK request for pending INVITE.
/// </summary>
/// <returns>Returns created ACK request.</returns>
private SIP_Request CreateAck()
{
/* RFC 3261 13.2.2.4.
* The header fields of the ACK are constructed
* in the same way as for any request sent within a dialog (see Section 12) with the
* exception of the CSeq and the header fields related to authentication. The sequence
* number of the CSeq header field MUST be the same as the INVITE being acknowledged,
* but the CSeq method MUST be ACK. The ACK MUST contain the same credentials as the INVITE.
*
* ACK must have same branch.
*/
SIP_Request ackRequest = m_pDialog.CreateRequest(SIP_Methods.ACK);
ackRequest.Via.AddToTop(m_pInvite.Via.GetTopMostValue().ToStringValue());
ackRequest.CSeq = new SIP_t_CSeq(m_pInvite.CSeq.SequenceNumber, SIP_Methods.ACK);
// Authorization
foreach (SIP_HeaderField h in m_pInvite.Authorization.HeaderFields)
{
ackRequest.Authorization.Add(h.Value);
}
// Proxy-Authorization
foreach (SIP_HeaderField h in m_pInvite.ProxyAuthorization.HeaderFields)
{
ackRequest.Authorization.Add(h.Value);
}
return(ackRequest);
}
