draft-bidulock-tsvwg-sctpnpi-00.me

No7信令,我需要交换类似的代码, 请店长审核,谢谢了,急着交换,谢谢

COOKIE-ACK chunk in response to a COOKIE-ECHO.  Therfore, unlike TCP,
\fBt_listen()\fR and \fBt_accept()\fR have similar semantics to that for ISO
providers.
.ip "\fIConnection Release\fR"
After a connection has been released, the local address(es) bound to the
endpoint may be qualified with the local IP address (rather than having a
wildcard IP address).  Also, the port number itself may have been changed
during the \fBt_accept()\fR processing.  If the endpoint is not being reused
immediately then it is recommended that it should be unbound or closed so that
other users can successfully bind to the address.

.sh 2 "Options"
.lp
Options are formatted according to the structure \fBt_opthdr\fR as described
in \fIThe Use of Options in XTI\fR.
.[
xti
.]
A transport provider compliant to this specification supports none, all or any
subset of the options defined in \fISCTP-Level Options\fR and
\fIIP-Level Options\fR.
.[
xti
.]
An implementation may restrict the use of any of these options by offering
them only in privileged or read-only mode.

.sh 3 "SCTP-Level Options"
.lp
The protocol level is \fBT_INET_SCTP\fR.  For this level,
\fISCTP-Level Options\fR shows the options that are defined.
.(l
.(c

\fC+-----------------+-------------------+----------------+
|   Option Name   |  Type of Option   |     Legal      |
|                 |       Value       |  Option Value  |
+-----------------+-------------------+----------------+
| T_SCTP_NODELAY  | t_uscalar_t       | T_YES/T_NO     |
| T_SCTP_MAXSEG   | t_uscalar_t       | T_YES/T_NO     |
| T_SCTP_CORK     | t_uscalar_t       | T_YES/T_NO     |
| T_SCTP_SID      | t_uscalar_t       | stream id      |
| T_SCTP_PPI      | t_uscalar_t       | payld proto id |
| T_SCTP_RECVSID  | t_uscalar_t       | T_YES/T_NO     |
| T_SCTP_RECVPPI  | t_uscalar_t       | T_YES/T_NO     |
| T_SCTP_RECVSSN  | t_uscalar_t       | T_YES/T_NO     |
| T_SCTP_HB       | struct t_sctp_hb  | (see text)     |
| T_SCTP_RTO      | struct t_sctp_rto | (see text)     |
+-----------------+-------------------+----------------+
.)c
.ce 1
\fBTable 4.\fR  SCTP-level Options
.)l
.lp
These options do \fBnot\fR have end-to-end significance.  The may be
negotiated in all XTI states except \fBT_UNBIND\fR and \fRT_UNINIT\fR.  They
are read-only in state \fBT_UNBND\fR.  See \fIThe Use of Options in XTI\fR
.[
xti
.]
for the differences between options that have end-to-end significance and
those that do not.
.sh 3 "Absolute Requirements"
.lp
A request for T_SCTP_NODELAY and a request to activate T_SCTP_KEEPALIVE is an
absolute requirement.  T_SCTP_MAXSEG is a read-only option.
.sh 3 "Further Remarks"
.ip "\fIT_SCTP_KEEPALIVE\fR"
If this option is set, the heartbeat mechanism of SCTP is activated on all
destination addresses to monitor idle destination addresses which may no
longer be reachable.  If a destination has been idle for the last heartbeat
timeout interval, a HEARTBEAT chunk is sent to check if the destination is
still alive or broken.

HEARTBEAT chunks are an explicit feature of SCTP, and this practice is part of
the SCTP Standard.  The option value consists of a structure \fBt_sctp_hb\fR
declared as:
.(l
.nf
\fCtypedef struct sctp_hb
    struct sctp_addr hb_dest;  /* destination address      */
    t_scalar_t       hb_onoff; /* activation flag          */
    t_scalar_t       hb_itvl;  /* interval in milliseconds */
} t_sctp_hb_t;
.fi
.)l
.ip
Legal values for the field \fIhb_dest\fR is a valid IP address which indicates
the destination addresses of the SCTP association for which the heartbeat
parameters are to be set.
.ip
Legal values for the field \fIhb_onoff\fR are:
.ba +8
.ip "\fBT_NO\fR" 8
switch the heartbeat for destination \fIhb_dest\fR off
.ip "\fBT_YES\fR" 8
activate the heartbeat for destination \fIhb_dest\fR
.ba -8
.ip
The field \fIhb_itvl\fR determines the frequency of HEARTBEAT chunks being
sent, in milliseconds.  The transport user can request the default value by
setting the field to \fBT_UNSPEC\fR.  The default is implementation-dependent,
but at least 60 seconds (see the referenced RFC 2960).  Legal values for this
field are \fBT_UNSPEC\fR and all positive numbers.

The timeout value is not an absolute requirement.  The implementation may pose
upper and lower limits to this value.  Requests that fall short of the lower
limit may be negotiated to the lower limit.

The use of this option might be restricted to priviledged users.
.ip "\fIT_SCTP_MAXSEG\fR"
This option is read-only.  It is used to retrieve the maximum SCTP segment
size.
.ip "\fIT_SCTP_NODELAY\fR"
Under some circumstances, SCTP sends data as soon as iti is presented.  When
outstanding data has not yet been acknowledged, it gathers small amounts of
output to be sent in a single packet once an acknowledgement is received.  For
a small number of clients, such as window systems (for example, MIT X Window
System) that send a stream of mouse events which receive no replies, this
packetization may cause significant delays.  T_SCTP_NODELAY is used to defeat
this algorithm.  Legal option values are \fBT_YES\fR ("don't delay") and
\fBT_NO\fR ("delay").
.ip "\fIT_SCTP_RTO\fR"

.sh 2 "Functions"
.ip "\fBt_accept\fR()"
Issuing a \fBt_accept\fR() assigns an already established connection to
\fIresfd\fR.  Since user data may be exchanged during the connection
establishment phase, \fIcall->udata.len\fR can be larger than 0.

When (\fIresfd != fd\fR), the function \fBt_accept\fR() is recommended to be
called with \fIresfd\fR in \fBT_UNBND\fR state, though an endpoint which is
bound to any local address (in \fBT_IDLE\fR) state) can also be used.

After \fBt_accept\fR() completes, the endpoint \fIresfd\fR will represent a
connected SCTP endpoint whose complete binding essentially has both local and
remote address components.

If file descriptor \fIresfd\fR was unbound before calling \fBt_accept\fR(),
after the call completes its local address binding would be to the same
protocol address bound to \fIfd\fR.  If file descriptor \fIresfd\fR was bound
to a local address before calling \fBt_accept\fR(), that local address binding
is dissolved and the local address part of the binding after \fBt_accept\fR()
completes would become the same as the address bound to \fIfd\fR.

If options with end-to-end significance (T_IP_OPTIONS, T_IP_TOS) are to be
sent with the connection confirmation, the values of these options must be set
with \fBt_optmgmt\fR() before the T_LISTEN event occurs.  When the transport
user detects a T_LISTEN, SCTP has already established the connection.
Association-related options passed with \fBt_accept\fR() become effective at
once, but since the connection is already established, they are transmitted
with subsequent IP datagrams sent out in the T_DATAXFER state.
.ip "\fBt_bind\fR()"
The \fIaddr\fR field of the \fBt_bind\fR structure represents the local
socket; that is, an address which specifically includes a port identifier.

Some implementations treat port number 0 as a request to bind to any unused
port.  Other than that value, a port number part of the binding is specific.
The IP address part of the binding can represent a single IP address or a list
of IP addresses or a wildcard binding to an address that could represent
multiple IP addresses that are legal for the host.
.ip "\fBt_close\fR()"
The \fBt_close\fR() call will result in a \fBclose\fR call on the descriptor
of this XTI communication endpoint.  If there are no other descriptors in this
process or any other process which reference this communication endpoint, the
\fBclose\fR() call will perform an orderly connection termination according to
the rules of a SCTP SHUTDOWN call on this connection endpoint as specified in
standard RFC 2960.
.[
rfc2960
.]
If the XTI_LINGER options is supported and is used to enable the \fIlinger\fR
option, the linger time will affect the time an implementation lingers in the
execution of \fBt_close\fR() or \fBclose\fR().  A linger time of 0 specified
with the XTI_LINGER option may cause an abortive release of a SCTP connection,
resulting in lost data.
.ip "\fBt_connect\fR()"
The \fIsndcall->addr\fR struct specifies the remote socket.  In the present
version, the returned address set in \fIrcvcall->addr\fR will have the same
value.  Since user data can be exchanged during the connection establishment
phase, \fIsndcall->udata.len\fR can be set to non-zero.

Note that the likely the peer SCTP, and not the peer transport user, will
confirm the connection.
.ip "\fBt_listen\fR()"
Upon successful return, \fBt_lister\fR() indicates an connection indication
and not an existing connection.  Since user data may be exchanged during the
connection establishment phase, \fIsndcall->udata.len\fR may be non-zero
before the call to \fBlisten\fR().  The \fIcall->addr\fR structure contains
the remote calling socket.
.ip "\fBt_open\fR()"
\fBt_open\fR() is called as the first step in the initialization of a
transport endpoint.  This function returns various default characteristics of
the underlying transport protocol by setting fields in the \fIt_info\fR
structure.  The following should be the values returned by the call to
\fBt_open\fR() and \fBt_getinfo\fR() with the indicated transport provider.
.lp
.(c
.nf
\fC+----------------+-------------+------------+
| Parameters     | Before call | After call |
+----------------+-------------+------------+
| name           |      x      |     /      |
| oflag          |      x      |     /      |
| info->addr     |      /      |     x      |
| info->options  |      /      |     x      |
| info->tsdu     |      /      | T_INFINITE |
| info->etsdu    |      /      | T_INFINITE |
| info->connect  |      /      |     x      |
| info->discon   |      /      |     0      |
| info->servtype |      /      | T_COTS_ORD |
| info->flags    |      /      |     0      |
+----------------+-------------+------------+
.fi
.)c
.ce 2
\fBTable 5.\fR  t_info parameters
`x' equals T_INVALID (-2) or an integral number greater than zero
.ip "\fBt_rcv\fR()"
The T_MORE flag should not be ignored if normal data is delivered.
Out-of-order data chunks are received with the T_EXPEDITED flag set.  If the
buffer supplied by the user is too small to hold all the data, the T_MORE
flag will be set, indicating that more data still remains to be read.
.ip "\fBt_rcvconnect\fR()"
Since user data can be exchanged during the connection establishment phase,
\fIcall->udata.maxlen\fR can be set to non-zero before the call to this
function.  On return, the \fIcall->addr\fR structure contains the address of
the remote calling endpoint.
.ip "\fBt_rcvdis\fR()"
Since data may not be sent with a disconnect, the \fIdiscon->udata\fR
structure will not be meaningful.
.ip "\fBt_snd\fR()"
The T_MORE flag should be used.  If \fBt_snd\fR() is called with the
T_EXPEDITED flag set, the data will be sent out-of-order on the specified SCTP
stream id.
.ip "\fBt_snddis\fR()"
Sincde data may not be sent with a disconnect, \fIcall->udata.len\fR must be
set to zero.
.ip "\fBt_sndudata\fR()"
Be aware that the maximum size of a connectionless-mode TSDU varies among
implementations.











.uh "Security Considerations"
.lp
There are no security considerations for this draft.

.uh "Acknowledgements"
.de ]<
.uh References
.ad l
.hy 0
.rm (f )f
..
.bp
.(l L
.[
$LIST$
.]
.)l

.uh "Author's Addresses"
.lp
.(b L
\fCBrian F. G. Bidulock                                Tel: [phone]
\fCOpenSS7 Corporation                          EMail: [e-mail]
\fC4701 Preston Park Boulevard, Suite 424                                 \-
\fCPlano, TX 75093                                                        \-
\fCUSA                                                                    \ 
.)b
.bl 2
.lp
This Internet Draft expires September 2001.
.ba +4
.bp
.(l I
.ce 1
.uh "List of Illustrations"
.bl 2
.xp 1
.)l
.bp
.(l I
.ce 1
.uh "Table of Contents"
.bl 2
.xp 0
.)l