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ng_uni(4)

NAME

     ng_uni -- netgraph UNI node type

SYNOPSIS

     #include <netnatm/sig/unidef.h>
     #include <netgraph/atm/ng_uni.h>

DESCRIPTION

     The uni netgraph node type implements ATM Forum signalling 4.0.

     After creation of the node, the UNI instance must be created by sending
     an ``enable'' message to the node.  If the node is enabled, the UNI
     parameters can be retrieved and modified, and the protocol can be
     started.

     The node is shut down either by an NGM_SHUTDOWN message, or when all
     hooks are disconnected.

HOOKS

     Each uni node has three hooks with fixed names:

     lower  This hook is the interface of the UNI protocol to the transport
	    layer of the ATM control plane.  The node expects the interface
	    exported by ng_sscfu(4) at this hook.

     upper  This hook is the ``user'' interface of the UNI protocol.  Because
	    there is no standardized interface at this point, this implementa-
	    tion follows more or less the interface specified by the SDL dia-
	    grams in ITU-T recommendations Q.2931 and Q.2971.  Normally either
	    a ng_ccatm(4) or a switch CAC should be stacked at this interface.
	    The message format at the upper hook is described below.  Because
	    netgraph(4) is functional, it makes sometimes sense to switch this
	    hook to queueing mode from the peer node upon connection.

     The upper interface of the uni node is loosely modelled after the inter-
     face specified in the ITU-T signalling standards.	There is however one
     derivation from this: normally there exists four kinds of signals:
     requests, responses, indications and confirmations.  These signals are
     usually triggered either by external events (receiving a message) or
     internal events (a timer or another signal).  This scheme works fine for
     user APIs that are entirely asynchronous, and in cases where error han-
     dling is not taken into account.  With synchronous APIs and error han-
     dling however, there is a problem.  If, for example, the application
     issues a request to set up a connection, it may do it by sending a
     SETUP.request signal to the UNI.  Normally, the UNI stack will send a
     SETUP message and receive a message from the switch (a RELEASE, CONNECT,
     CALL PROCEEDING or ALERTING), or a timer in the UNI stack will time out.
     In any of these cases, the UNI stack is supposed to report an event back
     to the application, and the application will unblock (in the case of a
     synchronous API) and handle the event.  The problem occurs when an error
     happens.  Suppose there is no memory to send the SETUP message and to
     start the timer.  In this case, the application will block forever
     because no received message and no timer will wake it up.	For this rea-
     son this implementation uses an additional message: for each signal sent
     from the application to the stack, the stack will respond with an error
     code.  If this code is zero, the stack has accepted the signal and the
     application may block; if the code is non-zero, the signal is effectively
	     uint32_t	     cookie;
	     u_char	     data[];
     };
     The sig field contains the actual signal that is sent from the user to
     UNI or from UNI to the user.  The cookie can be used by the user to cor-
     relate requests with events and responses.  If an error response, a con-
     firmation or an indication was triggered by a request or response, the
     cookie from that request or response is carried in the message from the
     stack to the user.  The cookie field is followed by the actual data for
     the signal.

     The signal is one of the following:

     enum uni_sig {
	 UNIAPI_ERROR,			     /* UNI -> API */

	 UNIAPI_CALL_CREATED,		     /* UNI -> API */
	 UNIAPI_CALL_DESTROYED, 	     /* UNI -> API */
	 UNIAPI_PARTY_CREATED,		     /* UNI -> API */
	 UNIAPI_PARTY_DESTROYED,	     /* UNI -> API */

	 UNIAPI_LINK_ESTABLISH_request,      /* API -> UNI */
	 UNIAPI_LINK_ESTABLISH_confirm,      /* UNI -> API */
	 UNIAPI_LINK_RELEASE_request,	     /* API -> UNI */
	 UNIAPI_LINK_RELEASE_confirm,	     /* UNI -> API */

	 UNIAPI_RESET_request,		     /* API -> UNI */
	 UNIAPI_RESET_confirm,		     /* UNI -> API */
	 UNIAPI_RESET_indication,	     /* UNI -> API */
	 UNIAPI_RESET_ERROR_indication,      /* UNI -> API */
	 UNIAPI_RESET_response, 	     /* API -> UNI */
	 UNIAPI_RESET_ERROR_response,	     /* API -> UNI */
	 UNIAPI_RESET_STATUS_indication,     /* UNI -> API */

	 UNIAPI_SETUP_request,		     /* API -> UNI */
	 UNIAPI_SETUP_indication,	     /* UNI -> API */
	 UNIAPI_SETUP_response, 	     /* API -> UNI */
	 UNIAPI_SETUP_confirm,		     /* UNI -> API */
	 UNIAPI_SETUP_COMPLETE_indication,   /* UNI -> API */
	 UNIAPI_ALERTING_request,	     /* API -> UNI */
	 UNIAPI_ALERTING_indication,	     /* UNI -> API */
	 UNIAPI_PROCEEDING_request,	     /* API -> UNI */
	 UNIAPI_PROCEEDING_indication,	     /* UNI -> API */
	 UNIAPI_RELEASE_request,	     /* API -> UNI */
	 UNIAPI_RELEASE_indication,	     /* UNI -> API */
	 UNIAPI_RELEASE_response,	     /* API -> UNI */
	 UNIAPI_RELEASE_confirm,	     /* UNI -> API */
	 UNIAPI_NOTIFY_request, 	     /* API -> UNI */
	 UNIAPI_NOTIFY_indication,	     /* UNI -> API */
	 UNIAPI_STATUS_indication,	     /* UNI -> API */
	 UNIAPI_STATUS_ENQUIRY_request,      /* API -> UNI */

	 UNIAPI_ADD_PARTY_request,	     /* API -> UNI */
	 UNIAPI_ADD_PARTY_indication,	     /* UNI -> API */
	 UNIAPI_PARTY_ALERTING_request,      /* API -> UNI */
	 UNIAPI_PARTY_ALERTING_indication,   /* UNI -> API */
	 UNIAPI_ADD_PARTY_ACK_request,	     /* API -> UNI */
	 UNIAPI_ADD_PARTY_ACK_indication,    /* UNI -> API */

	 UNIAPI_MAXSIG
     };

     The meaning of most of the signals can be deduced from the ITU-T SDLs.  A
     number of signals, however, is unique to this implementation:

     UNIAPI_ERROR
	     This is the error response, mentioned earlier.  It carries an
	     error code or zero, if the signal was accepted by the stack.

     UNIAPI_CALL_CREATED
	     The UNI stack has created a call instance either from an incoming
	     SETUP or from the user requesting an outgoing SETUP.  This may be
	     used to synchronize the creation and destroying of call data
	     between the UNI stack and the user.

     UNIAPI_CALL_DESTROYED
	     A call instance has been destroyed and all resources have been
	     freed.

     UNIAPI_PARTY_CREATED
	     A new party has been created for an existing point-to-multipoint
	     call.  This may be used to synchronize the creation and destroy-
	     ing of party data between the UNI stack and the user.

     UNIAPI_PARTY_DESTROYED
	     A party has been destroyed and all resources have been freed.

     UNIAPI_ABORT_CALL_request
	     This requests the stack to destroy the call instance and free all
	     its resources, without sending any messages to the network.

     UNIAPI_MAXSIG
	     This is not a signal, but rather a definition to get the number
	     of defined signals.

     Each of the signals is followed by a fixed size structure defined in
     <netnatm/sig/unidef.h>.

CONTROL MESSAGES

     The uni node understands the standard control messages, plus the follow-
     ing:

     NGM_UNI_SETDEBUG
	     Set debugging facility levels.  The UNI stack defines a number of
	     debugging facilities, each one associated with a debugging level.
	     If the debugging level of a facility is non-zero, text output
	     will be generated to the console.	The message uses the following
	     structure:

	     struct ngm_uni_debug {
		     uint32_t	     level[UNI_MAXFACILITY];
	     };

     NGM_UNI_SETDEBUG
	     Get debugging facility levels.  This returns an ngm_uni_debug
	     structure.
		     uint32_t option;	     /* other options */
		     uint32_t timer301;      /* T301 */
		     uint32_t timer303;      /* T303 */
		     uint32_t init303;	     /* T303 retransmission count */
		     uint32_t timer308;      /* T308 */
		     uint32_t init308;	     /* T308 retransmission count */
		     uint32_t timer309;      /* T309 */
		     uint32_t timer310;      /* T310 */
		     uint32_t timer313;      /* T313 */
		     uint32_t timer316;      /* T316 */
		     uint32_t init316;	     /* T316 retransmission count */
		     uint32_t timer317;      /* T317 */
		     uint32_t timer322;      /* T322 */
		     uint32_t init322;	     /* T322 retransmission count */
		     uint32_t timer397;      /* T397 */
		     uint32_t timer398;      /* T398 */
		     uint32_t timer399;      /* T399 */
	     };

	     The field proto specifies one of the following protocols:

	     enum uni_proto {
		     UNIPROTO_UNI40U,	     /* UNI4.0 user side */
		     UNIPROTO_UNI40N,	     /* UNI4.0 network side */
		     UNIPROTO_PNNI10,	     /* PNNI1.0 */
	     };

	     Some protocols may have options which can be set in popt:

	     enum uni_popt {
		     UNIPROTO_GFP,	     /* enable GFP */
	     };

	     The option field controls parsing and checking of messages:

	     enum uni_option {
		     UNIOPT_GIT_HARD,	     /* harder check of GIT IE */
		     UNIOPT_BEARER_HARD,     /* harder check of BEARER IE */
		     UNIOPT_CAUSE_HARD,      /* harder check of CAUSE IE */
	     };

	     All timer values are given in milliseconds.  Note, however, that
	     the actual resolution of the timers depend on system configura-
	     tion (see timeout(9)).

     NGM_UNI_SET_CONFIG
	     Change the UNI configuration.  This takes a

	     struct ngm_uni_set_config {
		     struct uni_config		     config;
		     struct ngm_uni_config_mask      mask;
	     };
	     struct ngm_uni_config_mask {
		     uint32_t	     mask;
		     uint32_t	     popt_mask;
		     uint32_t	     option_mask;
	     };

		     UNICFG_PROTO,
		     UNICFG_TIMER301,
		     UNICFG_TIMER303,
		     UNICFG_INIT303,
		     UNICFG_TIMER308,
		     UNICFG_INIT308,
		     UNICFG_TIMER309,
		     UNICFG_TIMER310,
		     UNICFG_TIMER313,
		     UNICFG_TIMER316,
		     UNICFG_INIT316,
		     UNICFG_TIMER317,
		     UNICFG_TIMER322,
		     UNICFG_INIT322,
		     UNICFG_TIMER397,
		     UNICFG_TIMER398,
		     UNICFG_TIMER399,
	     };

	     For popt_mask and option_mask, the definitions from enum uni_popt
	     and enum uni_option should be used.

     NGM_UNI_ENABLE
	     Create the UNI instance and enable processing.  Before the UNI is
	     enabled parameters cannot be retrieved or set.

     NGM_UNI_DISABLE
	     Destroy the UNI instance and free all resources.  Note, that con-
	     nections are not released.

SEE ALSO

     netgraph(4), ng_atm(4), ng_sscfu(4), ng_sscop(4), ngctl(8)

BUGS

     o	 LIJ (leaf-initiated-join) is not implemented yet.
     o	 GFP (generic functional protocol, Q.2932.1) is not yet implemented.
     o	 More testing needed.
     o	 PNNI not yet implemented.
     o	 Need to implement connection modification and the Q.2931 amendments.

AUTHORS

     The uni netgraph node and this manual page were written by Harti Brandt
     <harti@FreeBSD.org>

FreeBSD 5.4			October 6, 2003 		   FreeBSD 5.4

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