1diameter(3) Erlang Module Definition diameter(3)
2
6 diameter - Main API of the diameter application.
7
9 This module provides the interface with which a user can implement a
10 Diameter node that sends and receives messages using the Diameter pro‐
11 tocol as defined in RFC 6733.
12 Basic usage consists of creating a representation of a locally imple‐
14 mented Diameter node and its capabilities with start_service/2, adding
15 transport capability using add_transport/2 and sending Diameter
16 requests and receiving Diameter answers with call/4. Incoming Diameter
17 requests are communicated as callbacks to a diameter_app(3) callback
18 modules as specified in the service configuration.
19 Beware the difference between diameter (not capitalized) and Diameter
21 (capitalized). The former refers to the Erlang application named diame‐
22 ter whose main api is defined here, the latter to Diameter protocol in
23 the sense of RFC 6733.
24 The diameter application must be started before calling most functions
26 in this module.
27
29 Address():
30 DiameterIdentity():
33 Grouped():
36 OctetString():
39 Time():
42 Unsigned32():
45 UTF8String():
48 Types corresponding to RFC 6733 AVP Data Formats. Defined in diame‐
49 ter_dict(4).
50 application_alias() = term():
52 Name identifying a Diameter application in service configuration.
53 Passed to call/4 when sending requests defined by the application.
54 application_module() = Mod | [Mod | ExtraArgs] | #diameter_call‐
56 back{}:
57 Mod = atom()
60 ExtraArgs = list()
61 Module implementing the callback interface defined in diame‐
64 ter_app(3), along with any extra arguments to be appended to those
65 documented. Note that extra arguments specific to an outgoing
66 request can be specified to call/4, in which case those are are
67 appended to any module-specific extra arguments.
68 Specifying a #diameter_callback{} record allows individual func‐
70 tions to be configured in place of the usual diameter_app(3) call‐
71 backs. See diameter_callback.erl for details.
72 application_opt():
74 Options defining a Diameter application. Has one the following
75 types.
76 {alias, application_alias()}:
78 Unique identifier for the application in the scope of the ser‐
79 vice. Defaults to the value of the dictionary option.
80 {dictionary, atom()}:
82 Name of an encode/decode module for the Diameter messages defined
83 by the application. These modules are generated from files whose
84 format is documented in diameter_dict(4).
85 {module, application_module()}:
87 Callback module in which messages of the Diameter application are
88 handled. See diameter_app(3) for the required interface and
89 semantics.
90 {state, term()}:
92 Initial callback state. The prevailing state is passed to some
93 diameter_app(3) callbacks, which can then return a new state.
94 Defaults to the value of the alias option.
95 {call_mutates_state, true|false}:
97 Whether or not the pick_peer/4 application callback can modify
98 the application state. Defaults to false.
99 Warning:
101 pick_peer/4 callbacks are serialized when this option is true,
102 which is a potential performance bottleneck. A simple Diameter
103 client may suffer no ill effects from using mutable state but a
104 server or agent that responds to incoming request should probably
105 avoid it.
106 {answer_errors, callback|report|discard}:
109 Manner in which incoming answer messages containing decode errors
110 are handled.
111 If callback then errors result in a handle_answer/4 callback in
113 the same fashion as for handle_request/3, with errors communi‐
114 cated in the errors field of the #diameter_packet{} passed to the
115 callback. If report then an answer containing errors is discarded
116 without a callback and a warning report is written to the log. If
117 discard then an answer containing errors is silently discarded
118 without a callback. In both the report and discard cases the
119 return value for the call/4 invocation in question is as if a
120 callback had taken place and returned {error, failure}.
121 Defaults to discard.
123 {request_errors, answer_3xxx|answer|callback}:
125 Manner in which incoming requests are handled when an error other
126 than 3007 (DIAMETER_APPLICATION_UNSUPPORTED, which cannot be
127 associated with an application callback module), is detected.
128 If answer_3xxx then requests are answered without a han‐
130 dle_request/3 callback taking place. If answer then even 5xxx
131 errors are answered without a callback unless the connection in
132 question has configured the RFC 3588 common dictionary as noted
133 below. If callback then a handle_request/3 callback always takes
134 place and its return value determines the answer sent to the
135 peer, if any.
136 Defaults to answer_3xxx.
138 Note:
140 Answers sent by diameter set the E-bit in the Diameter Header.
141 Since RFC 3588 allows only 3xxx result codes in an answer-message,
142 answer has the same semantics as answer_3xxx when the transport in
143 question has been configured with diameter_gen_base_rfc3588 as its
144 common dictionary. Since RFC 6733 allows both 3xxx and 5xxx result
145 codes in an answer-message, a transport with diame‐
146 ter_gen_base_rfc6733 as its common dictionary does distinguish
147 between answer_3xxx and answer.
148 call_opt():
151 Options available to call/4 when sending an outgoing Diameter
152 request. Has one of the following types.
153 {extra, list()}:
155 Extra arguments to append to callbacks to the callback module in
156 question. These are appended to any extra arguments configured on
157 the callback itself. Multiple options append to the argument
158 list.
159 {filter, peer_filter()}:
161 Filter to apply to the list of available peers before passing it
162 to the pick_peer/4 callback for the application in question. Mul‐
163 tiple options are equivalent a single all filter on the corre‐
164 sponding list of filters. Defaults to none.
165 {peer, diameter_app:peer_ref()}:
167 Peer to which the request in question can be sent, preempting the
168 selection of peers having advertised support for the Diameter
169 application in question. Multiple options can be specified, and
170 their order is respected in the candidate lists passed to a sub‐
171 sequent pick_peer/4 callback.
172 {timeout, Unsigned32()}:
174 Number of milliseconds after which the request should timeout.
175 Defaults to 5000.
176 detach:
178 Cause call/4 to return ok as soon as the request in question has
179 been encoded, instead of waiting for and returning the result
180 from a subsequent handle_answer/4 or handle_error/4 callback.
181 An invalid option will cause call/4 to fail.
183 capability():
185 AVP values sent in outgoing CER or CEA messages during capabilities
186 exchange. Can be configured both on a service and a transport, val‐
187 ues on the latter taking precedence. Has one of the following
188 types.
189 {'Origin-Host', DiameterIdentity()}:
191 {'Origin-Realm', DiameterIdentity()}:
194 {'Host-IP-Address', [Address()]}:
197 An address list is available to the start function of a transport
198 module, which can return a new list for use in the subsequent CER
199 or CEA. Host-IP-Address need not be specified if the transport
200 module in question communicates an address list as described in
201 diameter_transport(3)
202 {'Vendor-Id', Unsigned32()}:
204 {'Product-Name', UTF8String()}:
207 {'Origin-State-Id', Unsigned32()}:
210 Origin-State-Id is optional but, if configured, will be included
211 in outgoing CER/CEA and DWR/DWA messages. Setting a value of 0
212 (zero) is equivalent to not setting a value, as documented in RFC
213 6733. The function origin_state_id/0 can be used as to retrieve a
214 value that is computed when the diameter application is started.
215 {'Supported-Vendor-Id', [Unsigned32()]}:
217 {'Auth-Application-Id', [Unsigned32()]}:
220 {'Inband-Security-Id', [Unsigned32()]}:
223 Inband-Security-Id defaults to the empty list, which is equiva‐
224 lent to a list containing only 0 (NO_INBAND_SECURITY). If 1 (TLS)
225 is specified then TLS is selected if the CER/CEA received from
226 the peer offers it.
227 {'Acct-Application-Id', [Unsigned32()]}:
229 {'Vendor-Specific-Application-Id', [Grouped()]}:
232 {'Firmware-Revision', Unsigned32()}:
235 Note that each tuple communicates one or more AVP values. It is an
238 error to specify duplicate tuples.
239 eval() = {M,F,A} | fun() | [eval() | A]:
241 An expression that can be evaluated as a function in the following
242 sense.
243 eval([{M,F,A} | T]) ->
245 apply(M, F, T ++ A);
246 eval([[F|A] | T]) ->
247 eval([F | T ++ A]);
248 eval([F|A]) ->
249 apply(F, A);
250 eval(F) ->
251 eval([F]).
252 Applying an eval() E to an argument list A is meant in the sense of
255 eval([E|A]).
256 Warning:
258 Beware of using fun expressions of the form fun Name/Arity in situa‐
259 tions in which the fun is not short-lived and code is to be upgraded
260 at runtime since any processes retaining such a fun will have a ref‐
261 erence to old code. In particular, such a value is typically inappro‐
262 priate in configuration passed to start_service/2 or add_transport/2.
263 peer_filter() = term():
266 Filter passed to call/4 in order to select candidate peers for a
267 pick_peer/4 callback. Has one of the following types.
268 none:
270 Matches any peer. This is a convenience that provides a filter
271 equivalent to no filter.
272 host:
274 Matches only those peers whose Origin-Host has the same value as
275 Destination-Host in the outgoing request in question, or any peer
276 if the request does not contain a Destination-Host AVP.
277 realm:
279 Matches only those peers whose Origin-Realm has the same value as
280 Destination-Realm in the outgoing request in question, or any
281 peer if the request does not contain a Destination-Realm AVP.
282 {host, any|DiameterIdentity()}:
284 Matches only those peers whose Origin-Host has the specified
285 value, or all peers if the atom any.
286 {realm, any|DiameterIdentity()}:
288 Matches only those peers whose Origin-Realm has the specified
289 value, or all peers if the atom any.
290 {eval, eval()}:
292 Matches only those peers for which the specified eval() returns
293 true when applied to the connection's diameter_caps record. Any
294 other return value or exception is equivalent to false.
295 {neg, peer_filter()}:
297 Matches only those peers not matched by the specified filter.
298 {all, [peer_filter()]}:
300 Matches only those peers matched by each filter in the specified
301 list.
302 {any, [peer_filter()]}:
304 Matches only those peers matched by at least one filter in the
305 specified list. The resulting list will be in match order, peers
306 matching the first filter of the list sorting before those
307 matched by the second, and so on.
308 {first, [peer_filter()]}:
310 Like any, but stops at the first filter for which there are
311 matches, which can be much more efficient when there are many
312 peers. For example, the following filter causes only peers best
313 matching both the host and realm filters to be presented.
314 {first, [{all, [host, realm]}, realm]}
316 An invalid filter is equivalent to {any,[]}, a filter that matches
319 no peer.
320 Note:
322 The host and realm filters cause the Destination-Host and Destina‐
323 tion-Realm AVPs to be extracted from the outgoing request, assuming
324 it to be a record- or list-valued diameter_codec:message(), and
325 assuming at most one of each AVP. If this is not the case then the
326 {host|realm, DiameterIdentity()} filters must be used to achieve the
327 desired result. An empty DiameterIdentity() (which should not be typ‐
328 ical) matches all hosts/realms for the purposes of filtering.
329 Warning:
332 A host filter is not typically desirable when setting Destination-
333 Host since it will remove peer agents from the candidates list.
334 service_event() = #diameter_event{service = service_name(), info =
337 service_event_info()}:
338 An event message sent to processes that have subscribed to these
339 using subscribe/1.
340 service_event_info() = term():
342 The info field of a service_event() record. Can have one of the
343 following types.
344 start:
346 stop:
349 The service is being started or stopped. No event precedes a
350 start event. No event follows a stop event, and this event
351 implies the termination of all transport processes.
352 {up, Ref, Peer, Config, Pkt}:
354 {up, Ref, Peer, Config}:
357 {down, Ref, Peer, Config}:
360 Ref = transport_ref()
363 Peer = diameter_app:peer()
364 Config = {connect|listen, [transport_opt()]}
365 Pkt = #diameter_packet{}
366 The RFC 3539 watchdog state machine has transitioned into (up) or
369 out of (down) the OKAY state. If a #diameter_packet{} is present
370 in an up event then there has been a capabilities exchange on a
371 newly established transport connection and the record contains
372 the received CER or CEA.
373 Note that a single up or down event for a given peer corresponds
375 to multiple peer_up/3 or peer_down/3 callbacks, one for each of
376 the Diameter applications negotiated during capabilities
377 exchange. That is, the event communicates connectivity with the
378 peer as a whole while the callbacks communicate connectivity with
379 respect to individual Diameter applications.
380 {reconnect, Ref, Opts}:
382 Ref = transport_ref()
385 Opts = [transport_opt()]
386 A connecting transport is attempting to establish/reestablish a
389 transport connection with a peer following connect_timer or
390 watchdog_timer expiry.
391 {closed, Ref, Reason, Config}:
393 Ref = transport_ref()
396 Config = {connect|listen, [transport_opt()]}
397 Capabilities exchange has failed. Reason can have one of the fol‐
400 lowing types.
401 {'CER', Result, Caps, Pkt}:
403 Result = ResultCode | {capabilities_cb, CB, ResultCode|discard}
406 Caps = #diameter_caps{}
407 Pkt = #diameter_packet{}
408 ResultCode = integer()
409 CB = eval()
410 An incoming CER has been answered with the indicated result
413 code, or discarded. Caps contains pairs of values, for the
414 local node and remote peer respectively. Pkt contains the CER
415 in question. In the case of rejection by a capabilities call‐
416 back, the tuple contains the rejecting callback.
417 {'CER', Caps, {ResultCode, Pkt}}:
419 ResultCode = integer()
422 Caps = #diameter_caps{}
423 Pkt = #diameter_packet{}
424 An incoming CER contained errors and has been answered with the
427 indicated result code. Caps contains values for the local node
428 only. Pkt contains the CER in question.
429 {'CER', timeout}:
431 An expected CER was not received within capx_timeout of connec‐
432 tion establishment.
433 {'CEA', Result, Caps, Pkt}:
435 Result = ResultCode | atom() | {capabilities_cb, CB, ResultCode|discard}
438 Caps = #diameter_caps{}
439 Pkt = #diameter_packet{}
440 ResultCode = integer()
441 An incoming CEA has been rejected for the indicated reason. An
444 integer-valued Result indicates the result code sent by the
445 peer. Caps contains pairs of values for the local node and
446 remote peer. Pkt contains the CEA in question. In the case of
447 rejection by a capabilities callback, the tuple contains the
448 rejecting callback.
449 {'CEA', Caps, Pkt}:
451 Caps = #diameter_caps{}
454 Pkt = #diameter_packet{}
455 An incoming CEA contained errors and has been rejected. Caps
458 contains only values for the local node. Pkt contains the CEA
459 in question.
460 {'CEA', timeout}:
462 An expected CEA was not received within capx_timeout of connec‐
463 tion establishment.
464 {watchdog, Ref, PeerRef, {From, To}, Config}:
466 Ref = transport_ref()
469 PeerRef = diameter_app:peer_ref()
470 From, To = initial | okay | suspect | down | reopen
471 Config = {connect|listen, [transport_opt()]}
472 An RFC 3539 watchdog state machine has changed state.
475 any():
477 For forward compatibility, a subscriber should be prepared to
478 receive info fields of forms other than the above.
479 service_name() = term():
481 Name of a service as passed to start_service/2 and with which the
482 service is identified. There can be at most one service with a
483 given name on a given node. Note that erlang:make_ref/0 can be used
484 to generate a service name that is somewhat unique.
485 service_opt():
487 Option passed to start_service/2. Can be any capability() as well
488 as the following.
489 {application, [application_opt()]}:
491 A Diameter application supported by the service.
492 A service must configure one tuple for each Diameter application
494 it intends to support. For an outgoing request, the relevant
495 application_alias() is passed to call/4, while for an incoming
496 request the application identifier in the message header deter‐
497 mines the application, the identifier being specified in the
498 application's dictionary file.
499 Warning:
501 The capabilities advertised by a node must match its configured
502 applications. In particular, application configuration must be
503 matched by corresponding capability() configuration, of *-Applica‐
504 tion-Id AVPs in particular.
505 {decode_format, record | list | map | none}:
508 The format of decoded messages and grouped AVPs in the msg field
509 of diameter_packet records and value field of diameter_avp
510 records respectively. If record then a record whose definition is
511 generated from the dictionary file in question. If list or map
512 then a [Name | Avps] pair where Avps is a list of AVP name/values
513 pairs or a map keyed on AVP names respectively. If none then the
514 atom-value message name, or undefined for a Grouped AVP. See also
515 diameter_codec:message().
516 Defaults to record.
518 Note:
520 AVPs are decoded into a list of diameter_avp records in avps field
521 of diameter_packet records independently of decode_format.
522 {restrict_connections, false | node | nodes | [node()] | eval()}:
525 The degree to which the service allows multiple transport connec‐
526 tions to the same peer, as identified by its Origin-Host at capa‐
527 bilities exchange.
528 If [node()] then a connection is rejected if another already
530 exists on any of the specified nodes. Types false, node, nodes
531 and eval() are equivalent to [], [node()], [node()|nodes()] and
532 the evaluated value respectively, evaluation of each expression
533 taking place whenever a new connection is to be established. Note
534 that false allows an unlimited number of connections to be estab‐
535 lished with the same peer.
536 Multiple connections are independent and governed by their own
538 peer and watchdog state machines.
539 Defaults to nodes.
541 {sequence, {H,N} | eval()}:
543 A constant value H for the topmost 32-N bits of of 32-bit End-to-
544 End and Hop-by-Hop Identifiers generated by the service, either
545 explicitly or as a return value of a function to be evaluated at
546 start_service/2. In particular, an identifier Id is mapped to a
547 new identifier as follows.
548 (H bsl N) bor (Id band ((1 bsl N) - 1))
550 Note that RFC 6733 requires that End-to-End Identifiers remain
553 unique for a period of at least 4 minutes and that this and the
554 call rate places a lower bound on appropriate values of N: at a
555 rate of R requests per second, an N-bit counter traverses all of
556 its values in (1 bsl N) div (R*60) minutes, so the bound is
557 4*R*60 =< 1 bsl N.
558 N must lie in the range 0..32 and H must be a non-negative inte‐
560 ger less than 1 bsl (32-N).
561 Defaults to {0,32}.
563 Warning:
565 Multiple Erlang nodes implementing the same Diameter node should be
566 configured with different sequence masks to ensure that each node
567 uses a unique range of End-to-End and Hop-by-Hop Identifiers for
568 outgoing requests.
569 {share_peers, boolean() | [node()] | eval()}:
572 Nodes to which peer connections established on the local Erlang
573 node are communicated. Shared peers become available in the
574 remote candidates list passed to pick_peer/4 callbacks on remote
575 nodes whose services are configured to use them: see
576 use_shared_peers below.
577 If false then peers are not shared. If [node()] then peers are
579 shared with the specified list of nodes. If eval() then peers are
580 shared with the nodes returned by the specified function, evalu‐
581 ated whenever a peer connection becomes available or a remote
582 service requests information about local connections. The value
583 true is equivalent to fun erlang:nodes/0. The value node() in a
584 list is ignored, so a collection of services can all be config‐
585 ured to share with the same list of nodes.
586 Defaults to false.
588 Note:
590 Peers are only shared with services of the same name for the pur‐
591 pose of sending outgoing requests. Since the value of the applica‐
592 tion_opt() alias, passed to call/4, is the handle for identifying a
593 peer as a suitable candidate, services that share peers must use
594 the same aliases to identify their supported applications. They
595 should typically also configure identical capabilities(), since by
596 sharing peer connections they are distributing the implementation
597 of a single Diameter node across multiple Erlang nodes.
598 {strict_arities, boolean() | encode | decode}:
601 Whether or not to require that the number of AVPs in a message or
602 grouped AVP agree with those specified in the dictionary in ques‐
603 tion when passing messages to diameter_app(3) callbacks. If true
604 then mismatches in an outgoing messages cause message encoding to
605 fail, while mismatches in an incoming message are reported as
606 5005/5009 errors in the errors field of the diameter_packet
607 record passed to handle_request/3 or handle_answer/4 callbacks.
608 If false then neither error is enforced/detected. If encode or
609 decode then errors are only enforced/detected on outgoing or
610 incoming messages respectively.
611 Defaults to true.
613 Note:
615 Disabling arity checks affects the form of messages at
616 encode/decode. In particular, decoded AVPs are represented as lists
617 of values, regardless of the AVP's arity (ie. expected number in
618 the message/AVP grammar in question), and values are expected to be
619 supplied as lists at encode. This differs from the historic decode
620 behaviour of representing AVPs of arity 1 as bare values, not
621 wrapped in a list.
622 {string_decode, boolean()}:
625 Whether or not to decode AVPs of type OctetString() and its
626 derived types DiameterIdentity(), DiameterURI(), IPFilterRule(),
627 QoSFilterRule(), and UTF8String(). If true then AVPs of these
628 types are decoded to string(). If false then values are retained
629 as binary().
630 Defaults to true.
632 Warning:
634 This option should be set to false since a sufficiently malicious
635 peer can otherwise cause large amounts of memory to be consumed
636 when decoded Diameter messages are passed between processes. The
637 default value is for backwards compatibility.
638 {traffic_counters, boolean()}:
641 Whether or not to count application-specific messages; those for
642 which diameter_app(3) callbacks take place. If false then only
643 messages handled by diameter itself are counted: CER/CEA,
644 DWR/DWA, DPR/DPA.
645 Defaults to true.
647 Note:
649 Disabling counters is a performance improvement, but means that the
650 omitted counters are not returned by service_info/2.
651 {use_shared_peers, boolean() | [node()] | eval()}:
654 Nodes from which communicated peers are made available in the
655 remote candidates list of pick_peer/4 callbacks.
656 If false then remote peers are not used. If [node()] then only
658 peers from the specified list of nodes are used. If eval() then
659 only peers returned by the specified function are used, evaluated
660 whenever a remote service communicates information about an
661 available peer connection. The value true is equivalent to fun
662 erlang:nodes/0. The value node() in a list is ignored.
663 Defaults to false.
665 Note:
667 A service that does not use shared peers will always pass the empty
668 list as the second argument of pick_peer/4 callbacks.
669 Warning:
672 Sending a request over a peer connection on a remote node is less
673 efficient than sending it over a local connection. It may be
674 preferable to make use of the service_opt() restrict_connections
675 and maintain a dedicated connection on each node from which
676 requests are sent.
677 transport_opt():
680 Any transport option except applications or capabilities. Used as
681 defaults for transport configuration, values passed to add_trans‐
682 port/2 overriding values configured on the service.
683 transport_opt():
685 Option passed to add_transport/2. Has one of the following types.
686 {applications, [application_alias()]}:
688 Diameter applications to which the transport should be
689 restricted. Defaults to all applications configured on the ser‐
690 vice in question. Applications not configured on the service in
691 question are ignored.
692 Warning:
694 The capabilities advertised by a node must match its configured
695 applications. In particular, setting applications on a transport
696 typically implies having to set matching *-Application-Id AVPs in a
697 capabilities() tuple.
698 {avp_dictionaries, [module()]}:
701 A list of alternate dictionary modules with which to
702 encode/decode AVPs that are not defined by the dictionary of the
703 application in question. At decode, such AVPs are represented as
704 diameter_avp records in the 'AVP' field of a decoded message or
705 Grouped AVP, the first alternate that succeeds in decoding the
706 AVP setting the record's value field. At encode, values in an
707 'AVP' list can be passed as AVP name/value 2-tuples, and it is an
708 encode error for no alternate to define the AVP of such a tuple.
709 Defaults to the empty list.
711 Note:
713 The motivation for alternate dictionaries is RFC 7683, Diameter
714 Overload Indication Conveyance (DOIC), which defines AVPs to be
715 piggybacked onto existing application messages rather than defining
716 an application of its own. The DOIC dictionary is provided by the
717 diameter application, as module diameter_gen_doic_rfc7683, but
718 alternate dictionaries can be used to encode/decode any set of AVPs
719 not known to an application dictionary.
720 {capabilities, [capability()]}:
723 AVPs used to construct outgoing CER/CEA messages. Values take
724 precedence over any specified on the service in question.
725 Specifying a capability as a transport option may be particularly
727 appropriate for Inband-Security-Id, in case TLS is desired over
728 TCP as implemented by diameter_tcp(3).
729 {capabilities_cb, eval()}:
731 Callback invoked upon reception of CER/CEA during capabilities
732 exchange in order to ask whether or not the connection should be
733 accepted. Applied to the transport_ref() and #diameter_caps{}
734 record of the connection.
735 The return value can have one of the following types.
737 ok:
739 Accept the connection.
740 integer():
742 Causes an incoming CER to be answered with the specified
743 Result-Code.
744 discard:
746 Causes an incoming CER to be discarded without CEA being sent.
747 unknown:
749 Equivalent to returning 3010, DIAMETER_UNKNOWN_PEER.
750 Returning anything but ok or a 2xxx series result code causes the
752 transport connection to be broken. Multiple capabilities_cb
753 options can be specified, in which case the corresponding call‐
754 backs are applied until either all return ok or one does not.
755 {capx_timeout, Unsigned32()}:
757 Number of milliseconds after which a transport process having an
758 established transport connection will be terminated if the
759 expected capabilities exchange message (CER or CEA) is not
760 received from the peer. For a connecting transport, the timing of
761 connection attempts is governed by connect_timer or watch‐
762 dog_timer expiry. For a listening transport, the peer determines
763 the timing.
764 Defaults to 10000.
766 {connect_timer, Tc}:
768 Tc = Unsigned32()
771 For a connecting transport, the RFC 6733 Tc timer, in millisec‐
774 onds. This timer determines the frequency with which a transport
775 attempts to establish an initial connection with its peer follow‐
776 ing transport configuration. Once an initial connection has been
777 established, watchdog_timer determines the frequency of reconnec‐
778 tion attempts, as required by RFC 3539.
779 For a listening transport, the timer specifies the time after
781 which a previously connected peer will be forgotten: a connection
782 after this time is regarded as an initial connection rather than
783 reestablishment, causing the RFC 3539 state machine to pass to
784 state OKAY rather than REOPEN. Note that these semantics are not
785 governed by the RFC and that a listening transport's con‐
786 nect_timer should be greater than its peer's Tw plus jitter.
787 Defaults to 30000 for a connecting transport and 60000 for a lis‐
789 tening transport.
790 {disconnect_cb, eval()}:
792 Callback invoked prior to terminating the transport process of a
793 transport connection having watchdog state OKAY. Applied to
794 application|service|transport and the transport_ref() and diame‐
795 ter_app:peer() in question: application indicates that the diame‐
796 ter application is being stopped, service that the service in
797 question is being stopped by stop_service/1, and transport that
798 the transport in question is being removed by remove_transport/2.
799 The return value can have one of the following types.
801 {dpr, [option()]}:
803 Send Disconnect-Peer-Request to the peer, the transport process
804 being terminated following reception of Disconnect-Peer-Answer
805 or timeout. An option() can be one of the following.
806 {cause, 0|rebooting|1|busy|2|goaway}:
808 Disconnect-Cause to send, REBOOTING, BUSY and
809 DO_NOT_WANT_TO_TALK_TO_YOU respectively. Defaults to reboot‐
810 ing for Reason=service|application and goaway for Rea‐
811 son=transport.
812 {timeout, Unsigned32()}:
814 Number of milliseconds after which the transport process is
815 terminated if DPA has not been received. Defaults to the
816 value of dpa_timeout.
817 dpr:
819 Equivalent to {dpr, []}.
820 close:
822 Terminate the transport process without Disconnect-Peer-Request
823 being sent to the peer.
824 ignore:
826 Equivalent to not having configured the callback.
827 Multiple disconnect_cb options can be specified, in which case
829 the corresponding callbacks are applied until one of them returns
830 a value other than ignore. All callbacks returning ignore is
831 equivalent to not having configured them.
832 Defaults to a single callback returning dpr.
834 {dpa_timeout, Unsigned32()}:
836 Number of milliseconds after which a transport connection is ter‐
837 minated following an outgoing DPR if DPA is not received.
838 Defaults to 1000.
840 {dpr_timeout, Unsigned32()}:
842 Number of milliseconds after which a transport connection is ter‐
843 minated following an incoming DPR if the peer does not close the
844 connection.
845 Defaults to 5000.
847 {incoming_maxlen, 0..16777215}:
849 Bound on the expected size of incoming Diameter messages. Mes‐
850 sages larger than the specified number of bytes are discarded.
851 Defaults to 16777215, the maximum value of the 24-bit Message
853 Length field in a Diameter Header.
854 {length_errors, exit|handle|discard}:
856 How to deal with errors in the Message Length field of the Diame‐
857 ter Header in an incoming message. An error in this context is
858 that the length is not at least 20 bytes (the length of a
859 Header), is not a multiple of 4 (a valid length) or is not the
860 length of the message in question, as received over the transport
861 interface documented in diameter_transport(3).
862 If exit then the transport process in question exits. If handle
864 then the message is processed as usual, a resulting han‐
865 dle_request/3 or handle_answer/4 callback (if one takes place)
866 indicating the 5015 error (DIAMETER_INVALID_MESSAGE_LENGTH). If
867 discard then the message in question is silently discarded.
868 Defaults to exit.
870 Note:
872 The default value reflects the fact that a transport module for a
873 stream-oriented transport like TCP may not be able to recover from
874 a message length error since such a transport must use the Message
875 Length header to divide the incoming byte stream into individual
876 Diameter messages. An invalid length leaves it with no reliable way
877 to rediscover message boundaries, which may result in the failure
878 of subsequent messages. See diameter_tcp(3) for the behaviour of
879 that module.
880 {pool_size, pos_integer()}:
883 Number of transport processes to start. For a listening trans‐
884 port, determines the size of the pool of accepting transport pro‐
885 cesses, a larger number being desirable for processing multiple
886 concurrent peer connection attempts. For a connecting transport,
887 determines the number of connections to the peer in question that
888 will be attempted to be establshed: the service_opt():
889 restrict_connections should also be configured on the service in
890 question to allow multiple connections to the same peer.
891 {spawn_opt, [term()]}:
893 Options passed to erlang:spawn_opt/2 when spawning a process for
894 an incoming Diameter request. Options monitor and link are
895 ignored.
896 Defaults to the empty list.
898 {strict_capx, boolean()]}:
900 Whether or not to enforce the RFC 6733 requirement that any mes‐
901 sage before capabilities exchange should close the peer connec‐
902 tion. If false then unexpected messages are discarded.
903 Defaults to true. Changing this results in non-standard behav‐
905 iour, but can be useful in case peers are known to be behave
906 badly.
907 {strict_mbit, boolean()}:
909 Whether or not to regard an AVP setting the M-bit as erroneous
910 when the command grammar in question does not explicitly allow
911 the AVP. If true then such AVPs are regarded as 5001 errors,
912 DIAMETER_AVP_UNSUPPORTED. If false then the M-bit is ignored and
913 policing it becomes the receiver's responsibility.
914 Defaults to true.
916 Warning:
918 RFC 6733 is unclear about the semantics of the M-bit. One the one
919 hand, the CCF specification in section 3.2 documents AVP in a com‐
920 mand grammar as meaning any arbitrary AVP; on the other hand, 1.3.4
921 states that AVPs setting the M-bit cannot be added to an existing
922 command: the modified command must instead be placed in a new Diam‐
923 eter application.
924 The reason for the latter is presumably interoperability: allowing
926 arbitrary AVPs setting the M-bit in a command makes its interpreta‐
927 tion implementation-dependent, since there's no guarantee that all
928 implementations will understand the same set of arbitrary AVPs in
929 the context of a given command. However, interpreting AVP in a com‐
930 mand grammar as any AVP, regardless of M-bit, renders 1.3.4 mean‐
931 ingless, since the receiver can simply ignore any AVP it thinks
932 isn't relevant, regardless of the sender's intent.
933 Beware of confusing mandatory in the sense of the M-bit with manda‐
935 tory in the sense of the command grammar. The former is a semantic
936 requirement: that the receiver understand the semantics of the AVP
937 in the context in question. The latter is a syntactic requirement:
938 whether or not the AVP must occur in the message in question.
939 {transport_config, term()}:
942 {transport_config, term(), Unsigned32() | infinity}:
945 Term passed as the third argument to the start/3 function of the
946 relevant transport module in order to start a transport process.
947 Defaults to the empty list.
948 The 3-tuple form additionally specifies an interval, in millisec‐
950 onds, after which a started transport process should be termi‐
951 nated if it has not yet established a connection. For example,
952 the following options on a connecting transport request a connec‐
953 tion with one peer over SCTP or another (typically the same) over
954 TCP.
955 {transport_module, diameter_sctp}
957 {transport_config, SctpOpts, 5000}
958 {transport_module, diameter_tcp}
959 {transport_config, TcpOpts}
960 To listen on both SCTP and TCP, define one transport for each.
963 {transport_module, atom()}:
965 Module implementing a transport process as defined in diame‐
966 ter_transport(3). Defaults to diameter_tcp.
967 Multiple transport_module and transport_config options are
969 allowed. The order of these is significant in this case (and only
970 in this case), a transport_module being paired with the first
971 transport_config following it in the options list, or the default
972 value for trailing modules. Transport starts will be attempted
973 with each of the modules in order until one establishes a connec‐
974 tion within the corresponding timeout (see below) or all fail.
975 {watchdog_config, [{okay|suspect, non_neg_integer()}]}:
977 Configuration that alters the behaviour of the watchdog state
978 machine. On key okay, the non-negative number of answered DWR
979 messages before transitioning from REOPEN to OKAY. On key sus‐
980 pect, the number of watchdog timeouts before transitioning from
981 OKAY to SUSPECT when DWR is unanswered, or 0 to not make the
982 transition.
983 Defaults to [{okay, 3}, {suspect, 1}]. Not specifying a key is
985 equivalent to specifying the default value for that key.
986 Warning:
988 The default value is as required by RFC 3539: changing it results
989 in non-standard behaviour that should only be used to simulate mis‐
990 behaving nodes during test.
991 {watchdog_timer, TwInit}:
994 TwInit = Unsigned32()
997 | {M,F,A}
998 The RFC 3539 watchdog timer. An integer value is interpreted as
1001 the RFC's TwInit in milliseconds, a jitter of +/- 2 seconds being
1002 added at each rearming of the timer to compute the RFC's Tw. An
1003 MFA is expected to return the RFC's Tw directly, with jitter
1004 applied, allowing the jitter calculation to be performed by the
1005 callback.
1006 An integer value must be at least 6000 as required by RFC 3539.
1008 Defaults to 30000.
1009 Unrecognized options are silently ignored but are returned unmodi‐
1011 fied by service_info/2 and can be referred to in predicate func‐
1012 tions passed to remove_transport/2.
1013 transport_ref() = reference():
1015 Reference returned by add_transport/2 that identifies the configu‐
1016 ration.
1017
1019 add_transport(SvcName, {connect|listen, [Opt]}) -> {ok, Ref} | {error,
1020 Reason}
1021 Types:
1023 SvcName = service_name()
1025 Opt = transport_opt()
1026 Ref = transport_ref()
1027 Reason = term()
1028 Add transport capability to a service.
1030 The service will start transport processes as required in order
1032 to establish a connection with the peer, either by connecting to
1033 the peer (connect) or by accepting incoming connection requests
1034 (listen). A connecting transport establishes transport connec‐
1035 tions with at most one peer, an listening transport potentially
1036 with many.
1037 The diameter application takes responsibility for exchanging
1039 CER/CEA with the peer. Upon successful completion of capabili‐
1040 ties exchange the service calls each relevant application mod‐
1041 ule's peer_up/3 callback after which the caller can exchange
1042 Diameter messages with the peer over the transport. In addition
1043 to CER/CEA, the service takes responsibility for the handling of
1044 DWR/DWA and required by RFC 3539, as well as for DPR/DPA.
1045 The returned reference uniquely identifies the transport within
1047 the scope of the service. Note that the function returns before
1048 a transport connection has been established.
1049 Note:
1051 It is not an error to add a transport to a service that has not
1052 yet been configured: a service can be started after configuring
1053 its transports.
1054 call(SvcName, App, Request, [Opt]) -> Answer | ok | {error, Reason}
1057 Types:
1059 SvcName = service_name()
1061 App = application_alias()
1062 Request = diameter_codec:message()
1063 Answer = term()
1064 Opt = call_opt()
1065 Send a Diameter request message.
1067 App specifies the Diameter application in which the request is
1069 defined and callbacks to the corresponding callback module will
1070 follow as described below and in diameter_app(3). Unless the
1071 detach option is specified, the call returns either when an
1072 answer message is received from the peer or an error occurs. In
1073 the answer case, the return value is as returned by a han‐
1074 dle_answer/4 callback. In the error case, whether or not the
1075 error is returned directly by diameter or from a handle_error/4
1076 callback depends on whether or not the outgoing request is suc‐
1077 cessfully encoded for transmission to the peer, the cases being
1078 documented below.
1079 If there are no suitable peers, or if pick_peer/4 rejects them
1081 by returning false, then {error,no_connection} is returned. Oth‐
1082 erwise pick_peer/4 is followed by a prepare_request/3 callback,
1083 the message is encoded and then sent.
1084 There are several error cases which may prevent an answer from
1086 being received and passed to a handle_answer/4 callback:
1087 * If the initial encode of the outgoing request fails, then
1089 the request process fails and {error,encode} is returned.
1090 * If the request is successfully encoded and sent but the
1092 answer times out then a handle_error/4 callback takes place
1093 with Reason = timeout.
1094 * If the request is successfully encoded and sent but the ser‐
1096 vice in question is stopped before an answer is received
1097 then a handle_error/4 callback takes place with Reason =
1098 cancel.
1099 * If the transport connection with the peer goes down after
1101 the request has been sent but before an answer has been
1102 received then an attempt is made to resend the request to an
1103 alternate peer. If no such peer is available, or if the sub‐
1104 sequent pick_peer/4 callback rejects the candidates, then a
1105 handle_error/4 callback takes place with Reason = failover.
1106 If a peer is selected then a prepare_retransmit/3 callback
1107 takes place, after which the semantics are the same as fol‐
1108 lowing an initial prepare_request/3 callback.
1109 * If an encode error takes place during retransmission then
1111 the request process fails and {error,failure} is returned.
1112 * If an application callback made in processing the request
1114 fails (pick_peer, prepare_request, prepare_retransmit, han‐
1115 dle_answer or handle_error) then either {error,encode} or
1116 {error,failure} is returned depending on whether or not
1117 there has been an attempt to send the request over the
1118 transport.
1119 Note that {error,encode} is the only return value which guaran‐
1121 tees that the request has not been sent over the transport con‐
1122 nection.
1123 origin_state_id() -> Unsigned32()
1125 Return a reasonable value for use as Origin-State-Id in outgoing
1127 messages.
1128 The value returned is the number of seconds since
1130 19680120T031408Z, the first value that can be encoded as a Diam‐
1131 eter Time(), at the time the diameter application was started.
1132 remove_transport(SvcName, Pred) -> ok | {error, Reason}
1134 Types:
1136 SvcName = service_name()
1138 Pred = Fun | MFA | transport_ref() | list() | true | false
1139 Fun = fun((transport_ref(), connect|listen, list()) -> bool‐
1141 ean())
1142 | fun((transport_ref(), list()) -> boolean())
1143 | fun((list()) -> boolean())
1144 MFA = {atom(), atom(), list()}
1145 Reason = term()
1146 Remove previously added transports.
1148 Pred determines which transports to remove. An arity-3-valued
1150 Pred removes all transports for which Pred(Ref, Type, Opts)
1151 returns true, where Type and Opts are as passed to add_trans‐
1152 port/2 and Ref is as returned by it. The remaining forms are
1153 equivalent to an arity-3 fun as follows.
1154 Pred = fun(transport_ref(), list()): fun(Ref, _, Opts) -> Pred(Ref, Opts) end
1156 Pred = fun(list()): fun(_, _, Opts) -> Pred(Opts) end
1157 Pred = transport_ref(): fun(Ref, _, _) -> Pred == Ref end
1158 Pred = list(): fun(_, _, Opts) -> [] == Pred -- Opts end
1159 Pred = true: fun(_, _, _) -> true end
1160 Pred = false: fun(_, _, _) -> false end
1161 Pred = {M,F,A}: fun(Ref, Type, Opts) -> apply(M, F, [Ref, Type, Opts | A]) end
1162 Removing a transport causes the corresponding transport pro‐
1165 cesses to be terminated. Whether or not a DPR message is sent to
1166 a peer is controlled by value of disconnect_cb configured on the
1167 transport.
1168 service_info(SvcName, Info) -> term()
1170 Types:
1172 SvcName = service_name()
1174 Info = Item | [Info]
1175 Item = atom()
1176 Return information about a started service. Requesting info for
1178 an unknown service causes undefined to be returned. Requesting a
1179 list of items causes a tagged list to be returned.
1180 Item can be one of the following.
1182 'Origin-Host':
1184 'Origin-Realm':
1187 'Vendor-Id':
1190 'Product-Name':
1193 'Origin-State-Id':
1196 'Host-IP-Address':
1199 'Supported-Vendor':
1202 'Auth-Application-Id':
1205 'Inband-Security-Id':
1208 'Acct-Application-Id':
1211 'Vendor-Specific-Application-Id':
1214 'Firmware-Revision':
1217 Return a capability value as configured with start_ser‐
1218 vice/2.
1219 applications:
1221 Return the list of applications as configured with
1222 start_service/2.
1223 capabilities:
1225 Return a tagged list of all capabilities values as config‐
1226 ured with start_service/2.
1227 transport:
1229 Return a list containing one entry for each of the service's
1230 transport as configured with add_transport/2. Each entry is
1231 a tagged list containing both configuration and information
1232 about established peer connections. An example return value
1233 with for a client service with Origin-Host "client.exam‐
1234 ple.com" configured with a single transport connected to
1235 "server.example.com" might look as follows.
1236 [[{ref,#Ref<0.0.0.93>},
1238 {type,connect},
1239 {options,[{transport_module,diameter_tcp},
1240 {transport_config,[{ip,{127,0,0,1}},
1241 {raddr,{127,0,0,1}},
1242 {rport,3868},
1243 {reuseaddr,true}]}]},
1244 {watchdog,{<0.66.0>,-576460736368485571,okay}},
1245 {peer,{<0.67.0>,-576460736357885808}},
1246 {apps,[{0,common}]},
1247 {caps,[{origin_host,{"client.example.com","server.example.com"}},
1248 {origin_realm,{"example.com","example.com"}},
1249 {host_ip_address,{[{127,0,0,1}],[{127,0,0,1}]}},
1250 {vendor_id,{0,193}},
1251 {product_name,{"Client","Server"}},
1252 {origin_state_id,{[],[]}},
1253 {supported_vendor_id,{[],[]}},
1254 {auth_application_id,{[0],[0]}},
1255 {inband_security_id,{[],[0]}},
1256 {acct_application_id,{[],[]}},
1257 {vendor_specific_application_id,{[],[]}},
1258 {firmware_revision,{[],[]}},
1259 {avp,{[],[]}}]},
1260 {port,[{owner,<0.69.0>},
1261 {module,diameter_tcp},
1262 {socket,{{127,0,0,1},48758}},
1263 {peer,{{127,0,0,1},3868}},
1264 {statistics,[{recv_oct,656},
1265 {recv_cnt,6},
1266 {recv_max,148},
1267 {recv_avg,109},
1268 {recv_dvi,19},
1269 {send_oct,836},
1270 {send_cnt,6},
1271 {send_max,184},
1272 {send_avg,139},
1273 {send_pend,0}]}]},
1274 {statistics,[{{{0,258,0},recv},3},
1275 {{{0,258,1},send},3},
1276 {{{0,258,0},recv,{'Result-Code',2001}},3},
1277 {{{0,257,0},recv},1},
1278 {{{0,257,1},send},1},
1279 {{{0,257,0},recv,{'Result-Code',2001}},1},
1280 {{{0,280,1},recv},2},
1281 {{{0,280,0},send},2},
1282 {{{0,280,0},send,{'Result-Code',2001}},2}]}]]
1283 Here ref is a transport_ref() and options the corresponding
1286 transport_opt() list passed to add_transport/2. The watchdog
1287 entry shows the state of a connection's RFC 3539 watchdog
1288 state machine. The peer entry identifies the diame‐
1289 ter_app:peer_ref() for which there will have been peer_up/3
1290 callbacks for the Diameter applications identified by the
1291 apps entry, common being the application_alias(). The caps
1292 entry identifies the capabilities sent by the local node and
1293 received from the peer during capabilities exchange. The
1294 port entry displays socket-level information about the
1295 transport connection. The statistics entry presents Diame‐
1296 ter-level counters, an entry like {{{0,280,1},recv},2} say‐
1297 ing that the client has received 2 DWR messages: {0,280,1} =
1298 {Application_Id, Command_Code, R_Flag}.
1299 Note that watchdog, peer, apps, caps and port entries depend
1301 on connectivity with the peer and may not be present. Note
1302 also that the statistics entry presents values accumulated
1303 during the lifetime of the transport configuration.
1304 A listening transport presents its information slightly dif‐
1306 ferently since there may be multiple accepted connections
1307 for the same transport_ref(). The transport info returned by
1308 a server with a single client connection might look as fol‐
1309 lows.
1310 [[{ref,#Ref<0.0.0.61>},
1312 {type,listen},
1313 {options,[{transport_module,diameter_tcp},
1314 {transport_config,[{reuseaddr,true},
1315 {ip,{127,0,0,1}},
1316 {port,3868}]}]},
1317 {accept,[[{watchdog,{<0.56.0>,-576460739249514012,okay}},
1318 {peer,{<0.58.0>,-576460638229179167}},
1319 {apps,[{0,common}]},
1320 {caps,[{origin_host,{"server.example.com","client.example.com"}},
1321 {origin_realm,{"example.com","example.com"}},
1322 {host_ip_address,{[{127,0,0,1}],[{127,0,0,1}]}},
1323 {vendor_id,{193,0}},
1324 {product_name,{"Server","Client"}},
1325 {origin_state_id,{[],[]}},
1326 {supported_vendor_id,{[],[]}},
1327 {auth_application_id,{[0],[0]}},
1328 {inband_security_id,{[],[]}},
1329 {acct_application_id,{[],[]}},
1330 {vendor_specific_application_id,{[],[]}},
1331 {firmware_revision,{[],[]}},
1332 {avp,{[],[]}}]},
1333 {port,[{owner,<0.62.0>},
1334 {module,diameter_tcp},
1335 {socket,{{127,0,0,1},3868}},
1336 {peer,{{127,0,0,1},48758}},
1337 {statistics,[{recv_oct,1576},
1338 {recv_cnt,16},
1339 {recv_max,184},
1340 {recv_avg,98},
1341 {recv_dvi,26},
1342 {send_oct,1396},
1343 {send_cnt,16},
1344 {send_max,148},
1345 {send_avg,87},
1346 {send_pend,0}]}]}],
1347 [{watchdog,{<0.72.0>,-576460638229717546,initial}}]]},
1348 {statistics,[{{{0,280,0},recv},7},
1349 {{{0,280,1},send},7},
1350 {{{0,280,0},recv,{'Result-Code',2001}},7},
1351 {{{0,258,1},recv},3},
1352 {{{0,258,0},send},3},
1353 {{{0,258,0},send,{'Result-Code',2001}},3},
1354 {{{0,280,1},recv},5},
1355 {{{0,280,0},send},5},
1356 {{{0,280,0},send,{'Result-Code',2001}},5},
1357 {{{0,257,1},recv},1},
1358 {{{0,257,0},send},1},
1359 {{{0,257,0},send,{'Result-Code',2001}},1}]}]]
1360 The information presented here is as in the connect case
1363 except that the client connections are grouped under an
1364 accept tuple.
1365 Whether or not the transport_opt() pool_size has been con‐
1367 figured affects the format of the listing in the case of a
1368 connecting transport, since a value greater than 1 implies
1369 multiple transport processes for the same transport_ref(),
1370 as in the listening case. The format in this case is similar
1371 to the listening case, with a pool tuple in place of an
1372 accept tuple.
1373 connections:
1375 Return a list containing one entry for every established
1376 transport connection whose watchdog state machine is not in
1377 the down state. This is a flat view of transport info which
1378 lists only active connections and for which Diameter-level
1379 statistics are accumulated only for the lifetime of the
1380 transport connection. A return value for the server above
1381 might look as follows.
1382 [[{ref,#Ref<0.0.0.61>},
1384 {type,accept},
1385 {options,[{transport_module,diameter_tcp},
1386 {transport_config,[{reuseaddr,true},
1387 {ip,{127,0,0,1}},
1388 {port,3868}]}]},
1389 {watchdog,{<0.56.0>,-576460739249514012,okay}},
1390 {peer,{<0.58.0>,-576460638229179167}},
1391 {apps,[{0,common}]},
1392 {caps,[{origin_host,{"server.example.com","client.example.com"}},
1393 {origin_realm,{"example.com","example.com"}},
1394 {host_ip_address,{[{127,0,0,1}],[{127,0,0,1}]}},
1395 {vendor_id,{193,0}},
1396 {product_name,{"Server","Client"}},
1397 {origin_state_id,{[],[]}},
1398 {supported_vendor_id,{[],[]}},
1399 {auth_application_id,{[0],[0]}},
1400 {inband_security_id,{[],[]}},
1401 {acct_application_id,{[],[]}},
1402 {vendor_specific_application_id,{[],[]}},
1403 {firmware_revision,{[],[]}},
1404 {avp,{[],[]}}]},
1405 {port,[{owner,<0.62.0>},
1406 {module,diameter_tcp},
1407 {socket,{{127,0,0,1},3868}},
1408 {peer,{{127,0,0,1},48758}},
1409 {statistics,[{recv_oct,10124},
1410 {recv_cnt,132},
1411 {recv_max,184},
1412 {recv_avg,76},
1413 {recv_dvi,9},
1414 {send_oct,10016},
1415 {send_cnt,132},
1416 {send_max,148},
1417 {send_avg,75},
1418 {send_pend,0}]}]},
1419 {statistics,[{{{0,280,0},recv},62},
1420 {{{0,280,1},send},62},
1421 {{{0,280,0},recv,{'Result-Code',2001}},62},
1422 {{{0,258,1},recv},3},
1423 {{{0,258,0},send},3},
1424 {{{0,258,0},send,{'Result-Code',2001}},3},
1425 {{{0,280,1},recv},66},
1426 {{{0,280,0},send},66},
1427 {{{0,280,0},send,{'Result-Code',2001}},66},
1428 {{{0,257,1},recv},1},
1429 {{{0,257,0},send},1},
1430 {{{0,257,0},send,{'Result-Code',2001}},1}]}]]
1431 Note that there may be multiple entries with the same ref,
1434 in contrast to transport info.
1435 statistics:
1437 Return a {{Counter, Ref}, non_neg_integer()} list of counter
1438 values. Ref can be either a transport_ref() or a diame‐
1439 ter_app:peer_ref(). Entries for the latter are folded into
1440 corresponding entries for the former as peer connections go
1441 down. Entries for both are removed at remove_transport/2.
1442 The Diameter-level statistics returned by transport and con‐
1443 nections info are based upon these entries.
1444 diameter_app:peer_ref():
1446 Return transport configuration associated with a single
1447 peer, as passed to add_transport/2. The returned list is
1448 empty if the peer is unknown. Otherwise it contains the ref,
1449 type and options tuples as in transport and connections info
1450 above. For example:
1451 [{ref,#Ref<0.0.0.61>},
1453 {type,accept},
1454 {options,[{transport_module,diameter_tcp},
1455 {transport_config,[{reuseaddr,true},
1456 {ip,{127,0,0,1}},
1457 {port,3868}]}]}]
1458 services() -> [SvcName]
1461 Types:
1463 SvcName = service_name()
1465 Return the list of started services.
1467 session_id(Ident) -> OctetString()
1469 Types:
1471 Ident = DiameterIdentity()
1473 Return a value for a Session-Id AVP.
1475 The value has the form required by section 8.8 of RFC 6733.
1477 Ident should be the Origin-Host of the peer from which the mes‐
1478 sage containing the returned value will be sent.
1479 start() -> ok | {error, Reason}
1481 Start the diameter application.
1483 The diameter application must be started before starting a ser‐
1485 vice. In a production system this is typically accomplished by a
1486 boot file, not by calling start/0 explicitly.
1487 start_service(SvcName, Options) -> ok | {error, Reason}
1489 Types:
1491 SvcName = service_name()
1493 Options = [service_opt()]
1494 Reason = term()
1495 Start a diameter service.
1497 A service defines a locally-implemented Diameter node, specify‐
1499 ing the capabilities to be advertised during capabilities
1500 exchange. Transports are added to a service using add_trans‐
1501 port/2.
1502 Note:
1504 A transport can both override its service's capabilities and
1505 restrict its supported Diameter applications so "service = Diam‐
1506 eter node as identified by Origin-Host" is not necessarily the
1507 case.
1508 stop() -> ok | {error, Reason}
1511 Stop the diameter application.
1513 stop_service(SvcName) -> ok | {error, Reason}
1515 Types:
1517 SvcName = service_name()
1519 Reason = term()
1520 Stop a diameter service.
1522 Stopping a service causes all associated transport connections
1524 to be broken. A DPR message with be sent as in the case of
1525 remove_transport/2.
1526 Note:
1528 Stopping a service does not remove any associated transports:
1529 remove_transport/2 must be called to remove transport configura‐
1530 tion.
1531 subscribe(SvcName) -> true
1534 Types:
1536 SvcName = service_name()
1538 Subscribe to service_event() messages from a service.
1540 It is not an error to subscribe to events from a service that
1542 does not yet exist. Doing so before adding transports is
1543 required to guarantee the reception of all transport-related
1544 events.
1545 unsubscribe(SvcName) -> true
1547 Types:
1549 SvcName = service_name()
1551 Unsubscribe to event messages from a service.
1553
1555 diameter_app(3), diameter_transport(3), diameter_dict(4)
1556Ericsson AB diameter 2.1.4.1 diameter(3)