| Platform SDK: Quality of Service |
The WSAConnect function is generally used by unicast receivers to join RSVP sessions. The behavior is somewhat different with TCP sessions and UDP unicast sessions.
TCP Sessions
The use of the WSAConnect function with RSVP-enabled TCP sessions is fairly simple, if somewhat stringent, because parameters match quite well between parameters associated with the WSAConnect function and parameters necessary for RSVP to operate. The following table illustrates which conditions of a TCP socket (left column) correspond to RSVP conditions (right column) that enable the TCP socket to join the session.
| TCP Socket is: | RSVP session is joined: |
|---|---|
| Not bound, or is bound and not connected (the WSAConnect function is not issued) | Never |
| Bound and connected | If both of the following conditions are true:
The port and address specified in any TCP session matches the socket's bound port and address. SenderTemplate, which is specified in PATH state associated with the session, matches the connected peer's port and address. |
UDP Unicast Sessions
The use of the WSAConnect function with RSVP-enabled UDP unicast sessions is less stringent than its use with TCP sessions, largely due to the fact that it is not always possible to determine unique addresses associated with a UDP socket. The following table illustrates which conditions of a UDP unicast socket (left column) correspond to RSVP conditions (right column) that enable the UDP unicast socket to join the session. These mappings do not apply to UDP multicast sessions.
| UDP unicast socket is: | RSVP session is joined: |
|---|---|
| Not bound and not connected. | Never |
| Bound using INADDR_ANY, and not connected (the WSAConnect function is not issued). | If the port specified in any UDP session matches the socket's bound port. |
| Bound using a specific address and not connected. | If the port and address specified in any UDP session matches the socket's bound port and address. |
| Bound using INADDR_ANY, and connected. | If both of the following conditions are true:
The port specified in any UDP session matches the socket's bound port. SenderTemplate, which is specified in PATH state associated with the UDP session, matches the connected peer's port and address. |
| Bound using a specific address and connected. | If both of the following conditions are true:
The port and address specified in any UDP session matches the socket's bound port and address. SenderTemplate, which is specified in PATH state associated with the session, matches the connected peer's port and address. |