The UDP or TCP port number used as a source
port for this sender in this session. If the
IP protocol in use, specified by
intSrvResvFwdProtocol is 50 (ESP) or 51 (AH),
this represents a generalized port identifier
(GPI). A value of zero indicates that the IP
protocol in use does not have ports. This ob-
ject may not be changed when the value of the
RowStatus object is 'active'.