NAME

       diameter_sctp - Diameter transport over SCTP.

DESCRIPTION

       This  module  implements  diameter  transport  over SCTP using gen_sctp(3erl). It can be specified as the
       value of a transport_module option to diameter:add_transport/2 and implements the behaviour documented in
       diameter_transport(3erl).

EXPORTS

       start({Type, Ref}, Svc, [Opt]) -> {ok, Pid, [LAddr]} | {error, Reason}

              Types:

                 Type = connect | accept
                 Ref = diameter:transport_ref()
                 Svc = #diameter_service{}
                 Opt = OwnOpt | SctpOpt
                 Pid = pid()
                 LAddr = inet:ip_address()
                 Reason = term()
                 OwnOpt = {raddr, inet:ip_address()} | {rport, integer()} | {accept, Match}
                 SctpOpt = term()
                 Match = inet:ip_address() | string() | [Match]

              The start function required by diameter_transport(3erl).

              Options raddr and rport specify the remote address and port for a  connecting  transport  and  not
              valid  for  a  listening  transport:  the  former  is  required  while  latter defaults to 3868 if
              unspecified. Multiple raddr options can be specified, in which case the  connecting  transport  in
              question attempts each in sequence until an association is established.

              Option  accept  specifies  remote  addresses  for  a  listening  transport  and is not valid for a
              connecting transport. If specified, a remote address that does not  match  one  of  the  specified
              addresses  causes  the  association  to  be  aborted.  Multiple accept options can be specified. A
              string-valued Match that does not parse as an address is interpreted as a regular expression.

              Remaining options are any accepted by gen_sctp:open/1, with the exception of options mode, binary,
              list, active and sctp_events. Note that options ip and port specify the  local  address  and  port
              respectively.

              Multiple  ip options can be specified for a multihomed peer. If none are specified then the values
              of Host-IP-Address in the #diameter_service{} record are used. (In particular, one of  these  must
              be  specified.)  Option  port  defaults  to  3868 for a listening transport and 0 for a connecting
              transport.

          Warning:
              An insufficiently large receive buffer may result in a peer having to  resend  incoming  messages:
              set the inet(3erl) option recbuf to increase the buffer size.

              An  insufficiently  large  send  buffer  may  result in outgoing messages being discarded: set the
              inet(3erl) option sndbuf to increase the buffer size.

              diameter_sctp uses the transport_data field of the #diameter_packet{} record  to  communicate  the
              stream  on  which  an inbound message has been received, or on which an outbound message should be
              sent:  the  value  will  be  of  the  form  {stream,  Id}  on  an  inbound  message  passed  to  a
              handle_request/3   or   handle_answer/4  callback.  For  an  outbound  message,  either  undefined
              (explicitly or by receiving the outbound message as a binary()) or a tuple should be  set  in  the
              return  value  of handle_request/3 (typically by retaining the value passed into this function) or
              prepare_request/3. The value undefined uses a "next outbound stream" id and increments this modulo
              the total number outbound streams. That is, successive  values  of  undefined  cycle  through  all
              outbound streams.

SEE ALSO

       diameter(3erl), diameter_transport(3erl), gen_sctp(3erl), inet(3erl)

Ericsson AB                                       diameter 1.5                               diameter_sctp(3erl)