/share/man/man4/ng_sscfu.4

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 27.\" Author: Hartmut Brandt <harti@FreeBSD.org>
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 29.\" $FreeBSD$
 30.\"
 31.\" ng_sscfu(4) man page
 32.\"
 33.Dd October 24, 2003
 34.Dt NG_SSCFU 4
 35.Os
 36.Sh NAME
 37.Nm ng_sscfu
 38.Nd netgraph SSCF at the UNI node type
 39.Sh SYNOPSIS
 40.In netnatm/saal/sscopdef.h
 41.In netnatm/saal/sscfudef.h
 42.In netgraph/atm/ng_sscfu.h
 43.Sh DESCRIPTION
 44The
 45.Nm sscfu
 46netgraph node type implements ITU-T recommendation Q.2130.
 47This recommendation specifies the Service Specific Coordination
 48Function at the UNI.
 49This is a thin sub-layer between the SSCOP (see
 50.Xr ng_sscop 4 )
 51and the UNI signalling.
 52This node does not really implement a protocol but
 53provides a mapping between the signals at the upper layer of the SSCOP and
 54the signals the UNI expects at its lower layer.
 55It also provides default values for the parameters of the SSCOP.
 56.Pp
 57After creation of the node, the SSCF instance must be created by sending
 58an
 59.Dq enable
 60message to the node.
 61If the node is enabled, default SSCOP parameters
 62can be retrieved and set in the corresponding SSCOP instance.
 63.Pp
 64The node is shut down either by a
 65.Dv NGM_SHUTDOWN
 66message, or when all hooks are disconnected.
 67.Sh HOOKS
 68Each
 69.Nm sscfu
 70node has two hooks with fixed names:
 71.Bl -tag -width ".Va upper"
 72.It Va lower
 73This hook is the interface to the SSCOP.
 74The interface expected here is exactly
 75that which is exported by the
 76.Xr ng_sscop 4
 77node type.
 78.It Va upper
 79This is the interface to the UNI.
 80It uses the following message format:
 81.Bd -literal
 82struct sscfu_arg {
 83	uint32_t sig;
 84	u_char	 data[];
 85};
 86.Ed
 87.Pp
 88The
 89.Va sig
 90field
 91is one of the following signals:
 92.Bd -literal
 93enum saal_sig {
 94    SAAL_ESTABLISH_request,	/* U -> SAAL: (UU) */
 95    SAAL_ESTABLISH_indication,	/* SAAL -> U: (UU) */
 96    SAAL_ESTABLISH_confirm,	/* SAAL -> U: (UU) */
 97    SAAL_RELEASE_request,	/* U -> SAAL: (UU) */
 98    SAAL_RELEASE_confirm,	/* SAAL -> U: */
 99    SAAL_RELEASE_indication,	/* SAAL -> U: (UU) */
100    SAAL_DATA_request,		/* U -> SAAL: (DATA) */
101    SAAL_DATA_indication,	/* SAAL -> U: (DATA) */
102    SAAL_UDATA_request,		/* U -> SAAL: (UDATA) */
103    SAAL_UDATA_indication,	/* SAAL -> U: (UDATA) */
104};
105.Ed
106.Pp
107The arrows in the comment show the direction of the signal, whether it
108is a signal that comes out of the node
109.Pq Ql -> ,
110or is sent by the node user to the node
111.Pq Ql <- .
112The type of the data expected for the signal is specified in parentheses.
113This data starts at the
114.Va data
115field of the message structure.
116.El
117.Pp
118If the
119.Va lower
120hook is disconnected and the node is enabled, the protocol state is
121reset.
122.Sh CONTROL MESSAGES
123The
124.Nm sscfu
125node understands the generic messages plus the following:
126.Bl -tag -width indent
127.It Dv NGM_SSCFU_GETDEFPARAM
128This message returns a
129.Vt sscop_param
130structure, which contains the default parameters for the SSCOP at the
131UNI.
132This structure should be used for a
133.Dv NGM_SSCOP_SETPARAM
134message to the SSCOP node below the SSCF.
135.It Dv NGM_SSCFU_ENABLE
136This message creates the actual SSCF instance and initializes it.
137Until this is done, parameters may neither be retrieved nor set,
138and all messages
139received on any hook are discarded.
140.It Dv NGM_SSCFU_DISABLE
141Destroy the SSCF instance.
142After this, all messages on any hooks are discarded.
143.It Dv NGM_SSCFU_GETDEBUG
144Retrieve the debugging flags in a
145.Vt uint32_t .
146.It Dv NGM_SSCFU_SETDEBUG
147Set debugging flags.
148The argument must be a
149.Vt uint32_t .
150.It Dv NGM_SSCFU_GETSTATE
151Retrieve the current state of the SSCFU instance in a
152.Vt uint32_t .
153If the node has not been enabled, 0 is returned.
154.El
155.Sh SEE ALSO
156.Xr netgraph 4 ,
157.Xr ng_atm 4 ,
158.Xr ng_sscop 4 ,
159.Xr ngctl 8
160.Sh AUTHORS
161.An Harti Brandt Aq harti@FreeBSD.org