cyclonedds/etc/cyclonedds.rnc

default namespace = "https://cdds.io/config"
namespace a = "http://relaxng.org/ns/compatibility/annotations/1.0"
grammar {
  start =
  [ a:documentation [ xml:lang="en" """
CycloneDDS configuration""" ] ]
  element CycloneDDS {
    [ a:documentation [ xml:lang="en" """
<p>The General element specifying Domain related settings.</p>""" ] ]
    element Domain {
      [ a:documentation [ xml:lang="en" """
<p>Domain id this configuration applies to, or "any" if it applies to all
domain ids.</p><p>The default value is: &quot;any&quot;.</p>""" ] ]
      attribute Id {
        text
      }?
      & [ a:documentation [ xml:lang="en" """
<p>The Compatibility elements allows specifying various settings related
to compatability with standards and with other DDSI implementations.</p>""" ] ]
      element Compatibility {
        [ a:documentation [ xml:lang="en" """
<p>This option assumes ParticipantMessageData endpoints required by the
liveliness protocol are present in RTI participants even when not
properly advertised by the participant discovery protocol.</p><p>The
default value is: &quot;false&quot;.</p>""" ] ]
        element AssumeRtiHasPmdEndpoints {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies whether QoS settings set to default values are
explicitly published in the discovery protocol. Implementations are to
use the default value for QoS settings not published, which allows a
significant reduction of the amount of data that needs to be exchanged
for the discovery protocol, but this requires all implementations to
adhere to the default values specified by the specifications.</p>

<p>When interoperability is required with an implementation that does not
follow the specifications in this regard, setting this option to true
will help.</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element ExplicitlyPublishQosSetToDefault {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This option specifies whether a network socket will be created for
each domain participant on a host. The specification seems to assume that
each participant has a unique address, and setting this option will
ensure this to be the case. This is not the defeault.</p>

<p>Disabling it slightly improves performance and reduces network traffic
somewhat. It also causes the set of port numbers needed by Cyclone DDS to
become predictable, which may be useful for firewall and NAT
configuration.</p><p>The default value is: &quot;single&quot;.</p>""" ] ]
        element ManySocketsMode {
          ("false"|"true"|"single"|"none"|"many")
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element sets the level of standards conformance of this instance
of the Cyclone DDS Service. Stricter conformance typically means less
interoperability with other implementations. Currently three modes are
defined:</p>

<ul><li><i>pedantic</i>: very strictly conform to the specification,
ultimately for compliancy testing, but currently of little value because
it adheres even to what will most likely turn out to be editing errors in
the DDSI standard. Arguably, as long as no errata have been published it
is the current text that is in effect, and that is what pedantic
currently does.</li>

<li><i>strict</i>: a slightly less strict view of the standard than does
pedantic: it follows the established behaviour where the standard is
obviously in error.</li>

<li><i>lax</i>: attempt to provide the smoothest possible
interoperability, anticipating future revisions of elements in the
standard in areas that other implementations do not adhere to, even
though there is no good reason not to.</li></ul>

<p>The default setting is "lax".</p><p>The default value is:
&quot;lax&quot;.</p>""" ] ]
        element StandardsConformance {
          ("lax"|"strict"|"pedantic")
        }?
      }*
      & [ a:documentation [ xml:lang="en" """
<p>This element is used to configure Cyclone DDS with the DDS Security
specification plugins and settings.</p>""" ] ]
      element DDSSecurity {
        [ a:documentation [ xml:lang="en" """
<p>This element configures the Access Control plugin of the DDS Security
specification.</p>""" ] ]
        element AccessControl {
          [ a:documentation [ xml:lang="en" """
<p>URI to the shared Governance Document signed by the Permissions CA in
S/MIME format</p>

<p>URI schemes: file, data</p><br>

<p>Examples file URIs:</p>

<p><Governance>file:governance.smime</Governance></p>

<p><Governance>file:/home/myuser/governance.smime</Governance></p><br>

<p><Governance><![CDATA[data:,MIME-Version: 1.0</p>

<p>Content-Type: multipart/signed;
protocol="application/x-pkcs7-signature"; micalg="sha-256";
boundary="----F9A8A198D6F08E1285A292ADF14DD04F"</p>

<p>This is an S/MIME signed message </p>

<p>------F9A8A198D6F08E1285A292ADF14DD04F</p>

<p><?xml version="1.0" encoding="UTF-8"?></p>

<p><dds xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"</p>

<p>xsi:noNamespaceSchemaLocation="omg_shared_ca_governance.xsd"></p>

<p><domain_access_rules></p>

<p> . . . </p>

<p></domain_access_rules></p>

<p></dds></p>

<p>...</p>

<p>------F9A8A198D6F08E1285A292ADF14DD04F</p>

<p>Content-Type: application/x-pkcs7-signature; name="smime.p7s"</p>

<p>Content-Transfer-Encoding: base64</p>

<p>Content-Disposition: attachment; filename="smime.p7s"</p>

<p>MIIDuAYJKoZIhv ...al5s=</p>

<p>------F9A8A198D6F08E1285A292ADF14DD04F-]]</Governance></p><p>The
default value is: &quot;&quot;.</p>""" ] ]
          element Governance {
            text
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element specifies the library to be loaded as the DDS Security
Access Control plugin.</p>""" ] ]
          element Library {
            [ a:documentation [ xml:lang="en" """
<p>This element names the finalization function of Access Control plugin.
This function is called to let the plugin release its
resources.</p><p>The default value is:
&quot;finalize_access_control&quot;.</p>""" ] ]
            attribute finalizeFunction {
              text
            }?
            & [ a:documentation [ xml:lang="en" """
<p>This element names the initialization function of Access Control
plugin. This function is called after loading the plugin library for
instantiation purposes. Init function must return an object that
implements DDS Security Access Control interface.</p><p>The default value
is: &quot;init_access_control&quot;.</p>""" ] ]
            attribute initFunction {
              text
            }?
            & [ a:documentation [ xml:lang="en" """
<p>This element points to the path of Access Control plugin library.</p>

<p>It can be either absolute path excluding file extension (
/usr/lib/dds_security_ac ) or single file without extension (
dds_security_ac ).</p>

<p>If single file is supplied, the library located by way of the current
working directory, or LD_LIBRARY_PATH for Unix systems, and PATH for
Windows systems.</p><p>The default value is:
&quot;dds_security_ac&quot;.</p>""" ] ]
            attribute path {
              text
            }?
          }?
          & [ a:documentation [ xml:lang="en" """
<p>URI to the DomainParticipant permissions document signed by the
Permissions CA in S/MIME format</p>

<p>The permissions document specifies the permissions to be applied to a
domain.</p><br>

<p>Example file URIs:</p>

<p><Permissions>file:permissions_document.p7s</Permissions></p>

<p><Permissions>file:/path_to/permissions_document.p7s</Permissions></p>

<p>Example data URI:</p>

<p><Permissions><![CDATA[data:,.........]]</Permissions></p><p>The
default value is: &quot;&quot;.</p>""" ] ]
          element Permissions {
            text
          }?
          & [ a:documentation [ xml:lang="en" """
<p>URI to a X509 certificate for the PermissionsCA in PEM format.</p>

<p>Supported URI schemes: file, data</p>

<p>The file and data schemas shall refer to a X.509 v3 certificate (see
X.509 v3 ITU-T Recommendation X.509 (2005) [39]) in PEM format.</p><br>

<p>Examples:</p><br>

<p><PermissionsCA>file:permissions_ca.pem</PermissionsCA></p>

<p><PermissionsCA>file:/home/myuser/permissions_ca.pem</PermissionsCA></p><br>

<p><PermissionsCA>data:<strong>,</strong>-----BEGIN CERTIFICATE-----</p>

<p>MIIC3DCCAcQCCQCWE5x+Z ... PhovK0mp2ohhRLYI0ZiyYQ==</p>

<p>-----END CERTIFICATE-----</PermissionsCA></p><p>The default value is:
&quot;&quot;.</p>""" ] ]
          element PermissionsCA {
            text
          }?
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element configures the Authentication plugin of the DDS Security
specification.</p>""" ] ]
        element Authentication {
          [ a:documentation [ xml:lang="en" """
<p>URI to the X509 certificate [39] of the Identity CA that is the signer
of Identity Certificate.</p>

<p>Supported URI schemes: file, data</p>

<p>The file and data schemas shall refer to a X.509 v3 certificate (see
X.509 v3 ITU-T Recommendation X.509 (2005) [39]) in PEM format.</p>

<p>Examples:</p>

<p><IdentityCA>file:identity_ca.pem</IdentityCA></p>

<p><IdentityCA>data:,-----BEGIN CERTIFICATE-----<br>

MIIC3DCCAcQCCQCWE5x+Z...PhovK0mp2ohhRLYI0ZiyYQ==<br>

-----END CERTIFICATE-----</IdentityCA></p>""" ] ]
          element IdentityCA {
            text
          }
          & [ a:documentation [ xml:lang="en" """
<p>Identity certificate that will be used for identifying all
participants in the OSPL instance.<br>The content is URI to a X509
certificate signed by the IdentityCA in PEM format containing the signed
public key.</p>

<p>Supported URI schemes: file, data</p>

<p>Examples:</p>

<p><IdentityCertificate>file:participant1_identity_cert.pem</IdentityCertificate></p>

<p><IdentityCertificate>data:,-----BEGIN CERTIFICATE-----<br>

MIIDjjCCAnYCCQDCEu9...6rmT87dhTo=<br>

-----END CERTIFICATE-----</IdentityCertificate></p>""" ] ]
          element IdentityCertificate {
            text
          }
          & [ a:documentation [ xml:lang="en" """
<p>The authentication handshake tokens may contain optional fields to be
included for finding interoperability problems.

If this parameter is set to true the optional fields are included in the
handshake token exchange.</p><p>The default value is:
&quot;false&quot;.</p>""" ] ]
          element IncludeOptionalFields {
            xsd:boolean
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element specifies the library to be loaded as the DDS Security
Access Control plugin.</p>""" ] ]
          element Library {
            [ a:documentation [ xml:lang="en" """
<p>This element names the finalization function of Authentication plugin.
This function is called to let the plugin release its
resources.</p><p>The default value is:
&quot;finalize_authentication&quot;.</p>""" ] ]
            attribute finalizeFunction {
              text
            }?
            & [ a:documentation [ xml:lang="en" """
<p>This element names the initialization function of Authentication
plugin. This function is called after loading the plugin library for
instantiation purposes. Init function must return an object that
implements DDS Security Authentication interface.</p><p>The default value
is: &quot;init_authentication&quot;.</p>""" ] ]
            attribute initFunction {
              text
            }?
            & [ a:documentation [ xml:lang="en" """
<p>This element points to the path of Authentication plugin library.</p>

<p>It can be either absolute path excluding file extension (
/usr/lib/dds_security_auth ) or single file without extension (
dds_security_auth ).</p>

<p>If single file is supplied, the library located by way of the current
working directory, or LD_LIBRARY_PATH for Unix systems, and PATH for
Windows systems.</p><p>The default value is:
&quot;dds_security_auth&quot;.</p>""" ] ]
            attribute path {
              text
            }?
          }?
          & [ a:documentation [ xml:lang="en" """
<p>A password used to decrypt the private_key.</p>

The value of the password property shall be interpreted as the Base64
encoding of the AES-128 key that shall be used to decrypt the private_key
using AES128-CBC.</p>

If the password property is not present, then the value supplied in the
private_key property must contain the unencrypted private key. </p><p>The
default value is: &quot;&quot;.</p>""" ] ]
          element Password {
            text
          }?
          & [ a:documentation [ xml:lang="en" """
<p>URI to access the private Private Key for all of the participants in
the OSPL federation.</p>

<p>Supported URI schemes: file, data</p>

<p>Examples:</p>

<p><PrivateKey>file:identity_ca_private_key.pem</PrivateKey></p>

<p><PrivateKey>data:,-----BEGIN RSA PRIVATE KEY-----<br>

MIIEpAIBAAKCAQEA3HIh...AOBaaqSV37XBUJg==<br>

-----END RSA PRIVATE KEY-----</PrivateKey></p>""" ] ]
          element PrivateKey {
            text
          }
          & [ a:documentation [ xml:lang="en" """
<p>Trusted CA Directory which contains trusted CA certificates as
separated files.</p><p>The default value is: &quot;&quot;.</p>""" ] ]
          element TrustedCADirectory {
            text
          }?
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element configures the Cryptographic plugin of the DDS Security
specification.</p>""" ] ]
        element Cryptographic {
          [ a:documentation [ xml:lang="en" """
<p>This element specifies the library to be loaded as the DDS Security
Cryptographic plugin.</p>""" ] ]
          element Library {
            [ a:documentation [ xml:lang="en" """
<p>This element names the finalization function of Cryptographic plugin.
This function is called to let the plugin release its
resources.</p><p>The default value is: &quot;finalize_crypto&quot;.</p>""" ] ]
            attribute finalizeFunction {
              text
            }?
            & [ a:documentation [ xml:lang="en" """
<p>This element names the initialization function of Cryptographic
plugin. This function is called after loading the plugin library for
instantiation purposes. Init function must return an object that
implements DDS Security Cryptographic interface.</p><p>The default value
is: &quot;init_crypto&quot;.</p>""" ] ]
            attribute initFunction {
              text
            }?
            & [ a:documentation [ xml:lang="en" """
<p>This element points to the path of Cryptographic plugin library.</p>

<p>It can be either absolute path excluding file extension (
/usr/lib/dds_security_crypto ) or single file without extension (
dds_security_crypto ).</p>

<p>If single file is supplied, the library located by way of the current
working directory, or LD_LIBRARY_PATH for Unix systems, and PATH for
Windows systems.</p><p>The default value is:
&quot;dds_security_crypto&quot;.</p>""" ] ]
            attribute path {
              text
            }?
          }?
        }?
      }*
      & [ a:documentation [ xml:lang="en" """
<p>The Discovery element allows specifying various parameters related to
the discovery of peers.</p>""" ] ]
      element Discovery {
        [ a:documentation [ xml:lang="en" """
<p>This setting controls for how long endpoints discovered via a Cloud
discovery service will survive after the discovery service disappeared,
allowing reconnect without loss of data when the discovery service
restarts (or another instance takes over).</p>

<p>Valid values are finite durations with an explicit unit or the keyword
'inf' for infinity. Recognised units: ns, us, ms, s, min, hr,
day.</p><p>The default value is: &quot;30 s&quot;.</p>""" ] ]
        element DSGracePeriod {
          duration_inf
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the default multicast address for all traffic
other than participant discovery packets. It defaults to
Discovery/SPDPMulticastAddress.</p><p>The default value is:
&quot;auto&quot;.</p>""" ] ]
        element DefaultMulticastAddress {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>An override for the domain id, to be used in discovery and for
determining the port number mapping. This allows creating multiple
domains in a single process while making them appear as a single domain
on the network. The value "default" disables the override.</p><p>The
default value is: &quot;default&quot;.</p>""" ] ]
        element ExternalDomainId {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the maximum DDSI participant index selected by
this instance of the Cyclone DDS service if the
Discovery/ParticipantIndex is "auto".</p><p>The default value is:
&quot;9&quot;.</p>""" ] ]
        element MaxAutoParticipantIndex {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the DDSI participant index used by this
instance of the Cyclone DDS service for discovery purposes. Only one such
participant id is used, independent of the number of actual
DomainParticipants on the node. It is either:</p>

<ul><li><i>auto</i>: which will attempt to automatically determine an
available participant index (see also Discovery/MaxAutoParticipantIndex),
or</li>

<li>a non-negative integer less than 120, or</li>

<li><i>none</i>:, which causes it to use arbitrary port numbers for
unicast sockets which entirely removes the constraints on the participant
index but makes unicast discovery impossible.</li></ul>

<p>The default is <i>auto</i>. The participant index is part of the port
number calculation and if predictable port numbers are needed and fixing
the participant index has no adverse effects, it is recommended that the
second be option be used.</p><p>The default value is:
&quot;none&quot;.</p>""" ] ]
        element ParticipantIndex {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element statically configures addresses for discovery.</p>

<p>Valid values are finite durations with an explicit unit or the keyword
'inf' for infinity. Recognised units: ns, us, ms, s, min, hr, day.</p>""" ] ]
        element Peers {
          [ a:documentation [ xml:lang="en" """
<p>This element statically configures a fault tolerant group of addresses
for discovery. Each member of the group is tried in sequence until one
succeeds.</p>""" ] ]
          element Group {
            [ a:documentation [ xml:lang="en" """
<p>This element statically configures an addresses for discovery.</p>""" ] ]
            element Peer {
              [ a:documentation [ xml:lang="en" """
<p>This element specifies an IP address to which discovery packets must
be sent, in addition to the default multicast address (see also
General/AllowMulticast). Both a hostnames and a numerical IP address is
accepted; the hostname or IP address may be suffixed with :PORT to
explicitly set the port to which it must be sent. Multiple Peers may be
specified.</p>""" ] ]
              attribute Address {
                text
              }
            }*
          }*
          & [ a:documentation [ xml:lang="en" """
<p>This element statically configures an addresses for discovery.</p>""" ] ]
          element Peer {
            [ a:documentation [ xml:lang="en" """
<p>This element specifies an IP address to which discovery packets must
be sent, in addition to the default multicast address (see also
General/AllowMulticast). Both a hostnames and a numerical IP address is
accepted; the hostname or IP address may be suffixed with :PORT to
explicitly set the port to which it must be sent. Multiple Peers may be
specified.</p>""" ] ]
            attribute Address {
              text
            }
          }*
        }?
        & [ a:documentation [ xml:lang="en" """
<p>The Ports element allows specifying various parameters related to the
port numbers used for discovery. These all have default values specified
by the DDSI 2.1 specification and rarely need to be changed.</p>""" ] ]
        element Ports {
          [ a:documentation [ xml:lang="en" """
<p>This element specifies the base port number (refer to the DDSI 2.1
specification, section 9.6.1, constant PB).</p><p>The default value is:
&quot;7400&quot;.</p>""" ] ]
          element Base {
            xsd:integer
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element specifies the domain gain, relating domain ids to sets of
port numbers (refer to the DDSI 2.1 specification, section 9.6.1,
constant DG).</p><p>The default value is: &quot;250&quot;.</p>""" ] ]
          element DomainGain {
            xsd:integer
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element specifies the port number for multicast data traffic
(refer to the DDSI 2.1 specification, section 9.6.1, constant
d2).</p><p>The default value is: &quot;1&quot;.</p>""" ] ]
          element MulticastDataOffset {
            xsd:integer
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element specifies the port number for multicast meta traffic
(refer to the DDSI 2.1 specification, section 9.6.1, constant
d0).</p><p>The default value is: &quot;0&quot;.</p>""" ] ]
          element MulticastMetaOffset {
            xsd:integer
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element specifies the participant gain, relating p0, articipant
index to sets of port numbers (refer to the DDSI 2.1 specification,
section 9.6.1, constant PG).</p><p>The default value is:
&quot;2&quot;.</p>""" ] ]
          element ParticipantGain {
            xsd:integer
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element specifies the port number for unicast data traffic (refer
to the DDSI 2.1 specification, section 9.6.1, constant d3).</p><p>The
default value is: &quot;11&quot;.</p>""" ] ]
          element UnicastDataOffset {
            xsd:integer
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element specifies the port number for unicast meta traffic (refer
to the DDSI 2.1 specification, section 9.6.1, constant d1).</p><p>The
default value is: &quot;10&quot;.</p>""" ] ]
          element UnicastMetaOffset {
            xsd:integer
          }?
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the interval between spontaneous transmissions
of participant discovery packets.</p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;30 s&quot;.</p>""" ] ]
        element SPDPInterval {
          duration
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the multicast address that is used as the
destination for the participant discovery packets. In IPv4 mode the
default is the (standardised) 239.255.0.1, in IPv6 mode it becomes
ff02::ffff:239.255.0.1, which is a non-standardised link-local multicast
address.</p><p>The default value is: &quot;239.255.0.1&quot;.</p>""" ] ]
        element SPDPMulticastAddress {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>String extension for domain id that remote participants must match to
be discovered.</p><p>The default value is: &quot;&quot;.</p>""" ] ]
        element Tag {
          text
        }?
      }*
      & [ a:documentation [ xml:lang="en" """
<p>The General element specifies overall Cyclone DDS service
settings.</p>""" ] ]
      element General {
        [ a:documentation [ xml:lang="en" """
<p>This element controls whether Cyclone DDS uses multicasts for data
traffic.</p>

<p>It is a comma-separated list of some of the following keywords:
"spdp", "asm", "ssm", or either of "false" or "true", or "default".</p>

<ul>

<li><i>spdp</i>: enables the use of ASM (any-source multicast) for
participant discovery, joining the multicast group on the discovery
socket, transmitting SPDP messages to this group, but never advertising
nor using any multicast address in any discovery message, thus forcing
unicast communications for all endpoint discovery and user data.</li>

<li><i>asm</i>: enables the use of ASM for all traffic, including
receiving SPDP but not transmitting SPDP messages via multicast</li>

<li><i>ssm</i>: enables the use of SSM (source-specific multicast) for
all non-SPDP traffic (if supported)</li>

</ul>

<p>When set to "false" all multicasting is disabled. The default, "true"
enables full use of multicasts. Listening for multicasts can be
controlled by General/MulticastRecvNetworkInterfaceAddresses.</p>

<p>"default" maps on spdp if the network is a WiFi network, on true if it
is a wired network</p><p>The default value is: &quot;default&quot;.</p>""" ] ]
        element AllowMulticast {
          xsd:token { pattern = "default|((false|spdp|asm|ssm|true)(,(false|spdp|asm|ssm|true))*)" }
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element allows setting the SO_DONTROUTE option for outgoing
packets, to bypass the local routing tables. This is generally useful
only when the routing tables cannot be trusted, which is highly
unusual.</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element DontRoute {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies whether Cyclone DDS allows IP multicast packets
to be visible to all DDSI participants in the same node, including
itself. It must be "true" for intra-node multicast communications, but if
a node runs only a single Cyclone DDS service and does not host any other
DDSI-capable programs, it should be set to "false" for improved
performance.</p><p>The default value is: &quot;true&quot;.</p>""" ] ]
        element EnableMulticastLoopback {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element allows explicitly overruling the network address Cyclone
DDS advertises in the discovery protocol, which by default is the address
of the preferred network interface (General/NetworkInterfaceAddress), to
allow Cyclone DDS to communicate across a Network Address Translation
(NAT) device.</p><p>The default value is: &quot;auto&quot;.</p>""" ] ]
        element ExternalNetworkAddress {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the network mask of the external network
address. This element is relevant only when an external network address
(General/ExternalNetworkAddress) is explicitly configured. In this case
locators received via the discovery protocol that are within the same
external subnet (as defined by this mask) will be translated to an
internal address by replacing the network portion of the external address
with the corresponding portion of the preferred network interface
address. This option is IPv4-only.</p><p>The default value is:
&quot;0.0.0.0&quot;.</p>""" ] ]
        element ExternalNetworkMask {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the size of DDSI sample fragments generated by
Cyclone DDS. Samples larger than FragmentSize are fragmented into
fragments of FragmentSize bytes each, except the last one, which may be
smaller. The DDSI spec mandates a minimum fragment size of 1025 bytes,
but Cyclone DDS will do whatever size is requested, accepting fragments
of which the size is at least the minimum of 1025 and FragmentSize.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;1280
B&quot;.</p>""" ] ]
        element FragmentSize {
          memsize
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the maximum size of the UDP payload that
Cyclone DDS will generate. Cyclone DDS will try to maintain this limit
within the bounds of the DDSI specification, which means that in some
cases (especially for very low values of MaxMessageSize) larger payloads
may sporadically be observed (currently up to 1192 B).</p>

<p>On some networks it may be necessary to set this item to keep the
packetsize below the MTU to prevent IP fragmentation. In those cases, it
is generally advisable to also consider reducing
Internal/FragmentSize.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;4096
B&quot;.</p>""" ] ]
        element MaxMessageSize {
          memsize
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies on which network interfaces Cyclone DDS listens
to multicasts. The following options are available:</p>

<ul>

<li><i>all</i>: listen for multicasts on all multicast-capable
interfaces; or</li>

<li><i>any</i>: listen for multicasts on the operating system default
interface; or</li>

<li><i>preferred</i>: listen for multicasts on the preferred interface
(General/NetworkInterfaceAddress); or</li>

<li><i>none</i>: does not listen for multicasts on any interface; or</li>

<li>a comma-separated list of network addresses: configures Cyclone DDS
to listen for multicasts on all of the listed addresses.</li>

</ul>

<p>If Cyclone DDS is in IPv6 mode and the address of the preferred
network interface is a link-local address, "all" is treated as a synonym
for "preferred" and a comma-separated list is treated as "preferred" if
it contains the preferred interface and as "none" if not.</p><p>The
default value is: &quot;preferred&quot;.</p>""" ] ]
        element MulticastRecvNetworkInterfaceAddresses {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the time-to-live setting for outgoing multicast
packets.</p><p>The default value is: &quot;32&quot;.</p>""" ] ]
        element MulticastTimeToLive {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the preferred network interface for use by
Cyclone DDS. The preferred network interface determines the IP address
that Cyclone DDS advertises in the discovery protocol (but see also
General/ExternalNetworkAddress), and is also the only interface over
which multicasts are transmitted. The interface can be identified by its
IP address, network interface name or network portion of the address. If
the value "auto" is entered here, Cyclone DDS will select what it
considers the most suitable interface.</p><p>The default value is:
&quot;auto&quot;.</p>""" ] ]
        element NetworkInterfaceAddress {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>When false (default) Cyclone DDS uses unicast for data whenever there
a single unicast suffices. Setting this to true makes it prefer
multicasting data, falling back to unicast only when no multicast address
is available.</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element PreferMulticast {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element allows selecting the transport to be used (udp, udp6,
tcp, tcp6, raweth)</p><p>The default value is: &quot;default&quot;.</p>""" ] ]
        element Transport {
          ("default"|"udp"|"udp6"|"tcp"|"tcp6"|"raweth")
        }?
        & [ a:documentation [ xml:lang="en" """
<p>Deprecated (use Transport instead)</p><p>The default value is:
&quot;default&quot;.</p>""" ] ]
        element UseIPv6 {
          ("false"|"true"|"default")
        }?
      }?
      & [ a:documentation [ xml:lang="en" """
<p>The Internal elements deal with a variety of settings that evolving
and that are not necessarily fully supported. For the vast majority of
the Internal settings, the functionality per-se is supported, but the
right to change the way the options control the functionality is
reserved. This includes renaming or moving options.</p>""" ] ]
      element Internal {
        [ a:documentation [ xml:lang="en" """
<p>Proxy readers that are assumed to sill be retrieving historical data
get this many samples retransmitted when they NACK something, even if
some of these samples have sequence numbers outside the set covered by
the NACK.</p><p>The default value is: &quot;0&quot;.</p>""" ] ]
        element AccelerateRexmitBlockSize {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls which network interfaces are assumed to be
capable of multicasting even when the interface flags returned by the
operating system state it is not (this provides a workaround for some
platforms). It is a comma-separated lists of patterns (with ? and *
wildcards) against which the interface names are matched.</p><p>The
default value is: &quot;&quot;.</p>""" ] ]
        element AssumeMulticastCapable {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting controls the interval with which a reader will continue
NACK'ing missing samples in the absence of a response from the writer, as
a protection mechanism against writers incorrectly stopping the sending
of HEARTBEAT messages.</p>

<p>Valid values are finite durations with an explicit unit or the keyword
'inf' for infinity. Recognised units: ns, us, ms, s, min, hr,
day.</p><p>The default value is: &quot;1 s&quot;.</p>""" ] ]
        element AutoReschedNackDelay {
          duration_inf
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls which participants will have which built-in
endpoints for the discovery and liveliness protocols. Valid values
are:</p>

<ul><li><i>full</i>: all participants have all endpoints;</li>

<li><i>writers</i>: all participants have the writers, but just one has
the readers;</li>

<li><i>minimal</i>: only one participant has built-in
endpoints.</li></ul>

<p>The default is <i>writers</i>, as this is thought to be compliant and
reasonably efficient. <i>Minimal</i> may or may not be compliant but is
most efficient, and <i>full</i> is inefficient but certain to be
compliant. See also Internal/ConservativeBuiltinReaderStartup.</p><p>The
default value is: &quot;writers&quot;.</p>""" ] ]
        element BuiltinEndpointSet {
          ("full"|"writers"|"minimal")
        }?
        & [ a:documentation [ xml:lang="en" """
<p>The ControlTopic element allows configured whether Cyclone DDS
provides a special control interface via a predefined topic or not.<p>""" ] ]
        element ControlTopic {
          empty
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element sets the maximum number of extra threads for an
experimental, undocumented and unsupported direct mode.</p><p>The default
value is: &quot;1&quot;.</p>""" ] ]
        element DDSI2DirectMaxThreads {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element sets the maximum number of samples that can be
defragmented simultaneously for a reliable writer. This has to be large
enough to handle retransmissions of historical data in addition to new
samples.</p><p>The default value is: &quot;16&quot;.</p>""" ] ]
        element DefragReliableMaxSamples {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element sets the maximum number of samples that can be
defragmented simultaneously for a best-effort writers.</p><p>The default
value is: &quot;4&quot;.</p>""" ] ]
        element DefragUnreliableMaxSamples {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls the Maximum size of a delivery queue, expressed
in samples. Once a delivery queue is full, incoming samples destined for
that queue are dropped until space becomes available again.</p><p>The
default value is: &quot;256&quot;.</p>""" ] ]
        element DeliveryQueueMaxSamples {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element enables expensive checks in builds with assertions
enabled and is ignored otherwise. Recognised categories are:</p>

<ul><li><i>whc</i>: writer history cache checking</li>

<li><i>rhc</i>: reader history cache checking</li>

<p>In addition, there is the keyword <i>all</i> that enables all
checks.</p><p>The default value is: &quot;&quot;.</p>""" ] ]
        element EnableExpensiveChecks {
          xsd:token { pattern = "((whc|rhc|all)(,(whc|rhc|all))*)|" }
        }?
        & [ a:documentation [ xml:lang="en" """
<p>When true, include keyhashes in outgoing data for topics with
keys.</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element GenerateKeyhash {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This elemnents allows configuring the base interval for sending writer
heartbeats and the bounds within it can vary.</p>

<p>Valid values are finite durations with an explicit unit or the keyword
'inf' for infinity. Recognised units: ns, us, ms, s, min, hr,
day.</p><p>The default value is: &quot;100 ms&quot;.</p>""" ] ]
        element HeartbeatInterval {
          [ a:documentation [ xml:lang="en" """
<p>This attribute sets the maximum interval for periodic heartbeats.</p>

<p>Valid values are finite durations with an explicit unit or the keyword
'inf' for infinity. Recognised units: ns, us, ms, s, min, hr,
day.</p><p>The default value is: &quot;8 s&quot;.</p>""" ] ]
          attribute max {
            duration_inf
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This attribute sets the minimum interval that must have passed since
the most recent heartbeat from a writer, before another asynchronous (not
directly related to writing) will be sent.</p>

<p>Valid values are finite durations with an explicit unit or the keyword
'inf' for infinity. Recognised units: ns, us, ms, s, min, hr,
day.</p><p>The default value is: &quot;5 ms&quot;.</p>""" ] ]
          attribute min {
            duration_inf
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This attribute sets the minimum interval for periodic heartbeats.
Other events may still cause heartbeats to go out.</p>

<p>Valid values are finite durations with an explicit unit or the keyword
'inf' for infinity. Recognised units: ns, us, ms, s, min, hr,
day.</p><p>The default value is: &quot;20 ms&quot;.</p>""" ] ]
          attribute minsched {
            duration_inf
          }?
          & duration_inf
        }?
        & [ a:documentation [ xml:lang="en" """
<p>Ack a sample only when it has been delivered, instead of when
committed to delivering it.</p><p>The default value is:
&quot;false&quot;.</p>""" ] ]
        element LateAckMode {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting controls the default participant lease duration. <p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;10 s&quot;.</p>""" ] ]
        element LeaseDuration {
          duration
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls whether or not implementation should internally
monitor its own liveliness. If liveliness monitoring is enabled, stack
traces can be dumped automatically when some thread appears to have
stopped making progress.</p><p>The default value is:
&quot;false&quot;.</p>""" ] ]
        element LivelinessMonitoring {
          [ a:documentation [ xml:lang="en" """
<p>This element controls the interval at which to check whether threads
have been making progress.</p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;1s&quot;.</p>""" ] ]
          attribute Interval {
            duration
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element controls whether or not to write stack traces to the
Cyclone DDS trace when a thread fails to make progress (on select
platforms only).</p><p>The default value is: &quot;true&quot;.</p>""" ] ]
          attribute StackTraces {
            xsd:boolean
          }?
          & xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This elements configures the maximum number of DCPS domain
participants this Cyclone DDS instance is willing to service. 0 is
unlimited.</p><p>The default value is: &quot;0&quot;.</p>""" ] ]
        element MaxParticipants {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting limits the maximum number of bytes queued for
retransmission. The default value of 0 is unlimited unless an
AuxiliaryBandwidthLimit has been set, in which case it becomes NackDelay
* AuxiliaryBandwidthLimit. It must be large enough to contain the largest
sample that may need to be retransmitted.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;50
kB&quot;.</p>""" ] ]
        element MaxQueuedRexmitBytes {
          memsize
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This settings limits the maximum number of samples queued for
retransmission.</p><p>The default value is: &quot;200&quot;.</p>""" ] ]
        element MaxQueuedRexmitMessages {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting controls the maximum (CDR) serialised size of samples
that Cyclone DDS will forward in either direction. Samples larger than
this are discarded with a warning.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;2147483647
B&quot;.</p>""" ] ]
        element MaxSampleSize {
          memsize
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element enables heartbeat-to-ack latency among Cyclone DDS
services by prepending timestamps to Heartbeat and AckNack messages and
calculating round trip times. This is non-standard behaviour. The
measured latencies are quite noisy and are currently not used
anywhere.</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element MeasureHbToAckLatency {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting controls the minimum size of socket receive buffers. The
operating system provides some size receive buffer upon creation of the
socket, this option can be used to increase the size of the buffer beyond
that initially provided by the operating system. If the buffer size
cannot be increased to the specified size, an error is reported.</p>

<p>The default setting is the word "default", which means Cyclone DDS
will attempt to increase the buffer size to 1MB, but will silently accept
a smaller buffer should that attempt fail.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is:
&quot;default&quot;.</p>""" ] ]
        element MinimumSocketReceiveBufferSize {
          memsize
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting controls the minimum size of socket send buffers. This
setting can only increase the size of the send buffer, if the operating
system by default creates a larger buffer, it is left unchanged.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;64
KiB&quot;.</p>""" ] ]
        element MinimumSocketSendBufferSize {
          memsize
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element allows configuring a service that dumps a text
description of part the internal state to TCP clients. By default (-1),
this is disabled; specifying 0 means a kernel-allocated port is used; a
positive number is used as the TCP port number.</p><p>The default value
is: &quot;-1&quot;.</p>""" ] ]
        element MonitorPort {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls whether all traffic is handled by a single
receive thread (false) or whether multiple receive threads may be used to
improve latency (true). By default it is disabled on Windows because it
appears that one cannot count on being able to send packets to oneself,
which is necessary to stop the thread during shutdown. Currently multiple
receive threads are only used for connectionless transport (e.g., UDP)
and ManySocketsMode not set to single (the default).</p><p>The default
value is: &quot;default&quot;.</p>""" ] ]
        element MultipleReceiveThreads {
          [ a:documentation [ xml:lang="en" """
<p>Receive threads dedicated to a single socket can only be triggered for
termination by sending a packet. Reception of any packet will do, so
termination failure due to packet loss is exceedingly unlikely, but to
eliminate all risks, it will retry as many times as specified by this
attribute before aborting.</p><p>The default value is:
&quot;4294967295&quot;.</p>""" ] ]
          attribute maxretries {
            xsd:integer
          }?
          & ("false"|"true"|"default")
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting controls the delay between receipt of a HEARTBEAT
indicating missing samples and a NACK (ignored when the HEARTBEAT
requires an answer). However, no NACK is sent if a NACK had been
scheduled already for a response earlier than the delay requests: then
that NACK will incorporate the latest information.</p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;10 ms&quot;.</p>""" ] ]
        element NackDelay {
          duration
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting controls the delay between the discovering a remote
writer and sending a pre-emptive AckNack to discover the range of data
available.</p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;10 ms&quot;.</p>""" ] ]
        element PreEmptiveAckDelay {
          duration
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element sets the maximum size in samples of a primary re-order
administration. Each proxy writer has one primary re-order administration
to buffer the packet flow in case some packets arrive out of order. Old
samples are forwarded to secondary re-order administrations associated
with readers in need of historical data.</p><p>The default value is:
&quot;128&quot;.</p>""" ] ]
        element PrimaryReorderMaxSamples {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls whether retransmits are prioritized over new
data, speeding up recovery.</p><p>The default value is:
&quot;true&quot;.</p>""" ] ]
        element PrioritizeRetransmit {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls for how long a remote participant that was
previously deleted will remain on a blacklist to prevent rediscovery,
giving the software on a node time to perform any cleanup actions it
needs to do. To some extent this delay is required internally by Cyclone
DDS, but in the default configuration with the 'enforce' attribute set to
false, Cyclone DDS will reallow rediscovery as soon as it has cleared its
internal administration. Setting it to too small a value may result in
the entry being pruned from the blacklist before Cyclone DDS is ready, it
is therefore recommended to set it to at least several seconds.</p>

<p>Valid values are finite durations with an explicit unit or the keyword
'inf' for infinity. Recognised units: ns, us, ms, s, min, hr,
day.</p><p>The default value is: &quot;10s&quot;.</p>""" ] ]
        element RediscoveryBlacklistDuration {
          [ a:documentation [ xml:lang="en" """
<p>This attribute controls whether the configured time during which
recently deleted participants will not be rediscovered (i.e., "black
listed") is enforced and following complete removal of the participant in
Cyclone DDS, or whether it can be rediscovered earlier provided all
traces of that participant have been removed already.</p><p>The default
value is: &quot;false&quot;.</p>""" ] ]
          attribute enforce {
            xsd:boolean
          }?
          & duration_inf
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This elements controls the addressing and timing of retransmits.
Possible values are:</p>

<ul><li><i>never</i>: retransmit only to the NACK-ing reader;</li>

<li><i>adaptive</i>: attempt to combine retransmits needed for
reliability, but send historical (transient-local) data to the requesting
reader only;</li>

<li><i>always</i>: do not distinguish between different causes, always
try to merge.</li></ul>

<p>The default is <i>never</i>. See also
Internal/RetransmitMergingPeriod.</p><p>The default value is:
&quot;never&quot;.</p>""" ] ]
        element RetransmitMerging {
          ("never"|"adaptive"|"always")
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting determines the size of the time window in which a NACK of
some sample is ignored because a retransmit of that sample has been
multicasted too recently. This setting has no effect on unicasted
retransmits.</p>

<p>See also Internal/RetransmitMerging.</p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;5 ms&quot;.</p>""" ] ]
        element RetransmitMergingPeriod {
          duration
        }?
        & [ a:documentation [ xml:lang="en" """
<p>Whether or not to locally retry pushing a received best-effort sample
into the reader caches when resource limits are reached.</p><p>The
default value is: &quot;false&quot;.</p>""" ] ]
        element RetryOnRejectBestEffort {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>Maximum pseudo-random delay in milliseconds between discovering a
remote participant and responding to it.</p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;0 ms&quot;.</p>""" ] ]
        element SPDPResponseMaxDelay {
          duration
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting allows the timing of scheduled events to be rounded up so
that more events can be handled in a single cycle of the event queue. The
default is 0 and causes no rounding at all, i.e. are scheduled exactly,
whereas a value of 10ms would mean that events are rounded up to the
nearest 10 milliseconds.</p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;0 ms&quot;.</p>""" ] ]
        element ScheduleTimeRounding {
          duration
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element sets the maximum size in samples of a secondary re-order
administration. The secondary re-order administration is per reader in
need of historical data.</p><p>The default value is: &quot;128&quot;.</p>""" ] ]
        element SecondaryReorderMaxSamples {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls whether the actual sending of packets occurs on
the same thread that prepares them, or is done asynchronously by another
thread.</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element SendAsync {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls whether Cyclone DDS advertises all the domain
participants it serves in DDSI (when set to <i>false</i>), or rather only
one domain participant (the one corresponding to the Cyclone DDS process;
when set to <i>true</i>). In the latter case Cyclone DDS becomes the
virtual owner of all readers and writers of all domain participants,
dramatically reducing discovery traffic (a similar effect can be obtained
by setting Internal/BuiltinEndpointSet to "minimal" but with less loss of
information).</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element SquashParticipants {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls whether samples sent by a writer with QoS
settings transport_priority >= SynchronousDeliveryPriorityThreshold and a
latency_budget at most this element's value will be delivered
synchronously from the "recv" thread, all others will be delivered
asynchronously through delivery queues. This reduces latency at the
expense of aggregate bandwidth.</p>

<p>Valid values are finite durations with an explicit unit or the keyword
'inf' for infinity. Recognised units: ns, us, ms, s, min, hr,
day.</p><p>The default value is: &quot;inf&quot;.</p>""" ] ]
        element SynchronousDeliveryLatencyBound {
          duration_inf
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls whether samples sent by a writer with QoS
settings latency_budget <= SynchronousDeliveryLatencyBound and
transport_priority greater than or equal to this element's value will be
delivered synchronously from the "recv" thread, all others will be
delivered asynchronously through delivery queues. This reduces latency at
the expense of aggregate bandwidth.</p><p>The default value is:
&quot;0&quot;.</p>""" ] ]
        element SynchronousDeliveryPriorityThreshold {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>Testing options.</p>""" ] ]
        element Test {
          [ a:documentation [ xml:lang="en" """
<p>This element controls the fraction of outgoing packets to drop,
specified as samples per thousand.</p><p>The default value is:
&quot;0&quot;.</p>""" ] ]
          element XmitLossiness {
            xsd:integer
          }?
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element controls whether the response to a newly discovered
participant is sent as a unicasted SPDP packet, instead of rescheduling
the periodic multicasted one. There is no known benefit to setting this
to <i>false</i>.</p><p>The default value is: &quot;true&quot;.</p>""" ] ]
        element UnicastResponseToSPDPMessages {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>Do not use.</p><p>The default value is: &quot;0&quot;.</p>""" ] ]
        element UseMulticastIfMreqn {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>Watermarks for flow-control.</p>""" ] ]
        element Watermarks {
          [ a:documentation [ xml:lang="en" """
<p>This element controls whether Cyclone DDS will adapt the high-water
mark to current traffic conditions, based on retransmit requests and
transmit pressure.</p><p>The default value is: &quot;true&quot;.</p>""" ] ]
          element WhcAdaptive {
            xsd:boolean
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element sets the maximum allowed high-water mark for the Cyclone
DDS WHCs, expressed in bytes. A writer is suspended when the WHC reaches
this size.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;100
kB&quot;.</p>""" ] ]
          element WhcHigh {
            memsize
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element sets the initial level of the high-water mark for the
Cyclone DDS WHCs, expressed in bytes.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;30
kB&quot;.</p>""" ] ]
          element WhcHighInit {
            memsize
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element sets the low-water mark for the Cyclone DDS WHCs,
expressed in bytes. A suspended writer resumes transmitting when its
Cyclone DDS WHC shrinks to this size.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;1 kB&quot;.</p>""" ] ]
          element WhcLow {
            memsize
          }?
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element enables the batching of write operations. By default each
write operation writes through the write cache and out onto the
transport. Enabling write batching causes multiple small write operations
to be aggregated within the write cache into a single larger write. This
gives greater throughput at the expense of latency. Currently there is no
mechanism for the write cache to automatically flush itself, so that if
write batching is enabled, the application may havee to use the
dds_write_flush function to ensure thta all samples are
written.</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element WriteBatch {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This setting controls the maximum duration for which actual deletion
of a reliable writer with unacknowledged data in its history will be
postponed to provide proper reliable transmission.<p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;1 s&quot;.</p>""" ] ]
        element WriterLingerDuration {
          duration
        }?
      }*
      & [ a:documentation [ xml:lang="en" """
<p>The Partitioning element specifies Cyclone DDS network partitions and
how DCPS partition/topic combinations are mapped onto the network
partitions.</p>""" ] ]
      element Partitioning {
        [ a:documentation [ xml:lang="en" """
<p>The IgnoredPartitions element specifies DCPS partition/topic
combinations that are not distributed over the network.</p>""" ] ]
        element IgnoredPartitions {
          [ a:documentation [ xml:lang="en" """
<p>This element can be used to prevent certain combinations of DCPS
partition and topic from being transmitted over the network. Cyclone DDS
will complete ignore readers and writers for which all DCPS partitions as
well as their topic is ignored, not even creating DDSI readers and
writers to mirror the DCPS ones.</p>""" ] ]
          element IgnoredPartition {
            [ a:documentation [ xml:lang="en" """
<p>This attribute specifies a partition and a topic expression, separated
by a single '.', that are used to determine if a given partition and
topic will be ignored or not. The expressions may use the usual wildcards
'*' and '?'. Cyclone DDS will consider an wildcard DCPS partition to
match an expression iff there exists a string that satisfies both
expressions.</p>""" ] ]
            attribute DCPSPartitionTopic {
              text
            }
          }*
        }*
        & [ a:documentation [ xml:lang="en" """
<p>The NetworkPartitions element specifies the Cyclone DDS network
partitions.</p>""" ] ]
        element NetworkPartitions {
          [ a:documentation [ xml:lang="en" """
<p>This element defines a Cyclone DDS network partition.</p>""" ] ]
          element NetworkPartition {
            [ a:documentation [ xml:lang="en" """
<p>This attribute specifies the multicast addresses associated with the
network partition as a comma-separated list. Readers matching this
network partition (cf. Partitioning/PartitionMappings) will listen for
multicasts on all of these addresses and advertise them in the discovery
protocol. The writers will select the most suitable address from the
addresses advertised by the readers.</p>""" ] ]
            attribute Address {
              text
            }
            & [ a:documentation [ xml:lang="en" """
<p>This attribute is a placeholder.</p><p>The default value is:
&quot;true&quot;.</p>""" ] ]
            attribute Connected {
              xsd:boolean
            }?
            & [ a:documentation [ xml:lang="en" """
<p>This attribute specifies the name of this Cyclone DDS network
partition. Two network partitions cannot have the same name.</p>""" ] ]
            attribute Name {
              text
            }
          }*
        }*
        & [ a:documentation [ xml:lang="en" """
<p>The PartitionMappings element specifies the mapping from DCPS
partition/topic combinations to Cyclone DDS network partitions.</p>""" ] ]
        element PartitionMappings {
          [ a:documentation [ xml:lang="en" """
<p>This element defines a mapping from a DCPS partition/topic combination
to a Cyclone DDS network partition. This allows partitioning data flows
by using special multicast addresses for part of the data and possibly
also encrypting the data flow.</p>""" ] ]
          element PartitionMapping {
            [ a:documentation [ xml:lang="en" """
<p>This attribute specifies a partition and a topic expression, separated
by a single '.', that are used to determine if a given partition and
topic maps to the Cyclone DDS network partition named by the
NetworkPartition attribute in this PartitionMapping element. The
expressions may use the usual wildcards '*' and '?'. Cyclone DDS will
consider a wildcard DCPS partition to match an expression if there exists
a string that satisfies both expressions.</p>""" ] ]
            attribute DCPSPartitionTopic {
              text
            }
            & [ a:documentation [ xml:lang="en" """
<p>This attribute specifies which Cyclone DDS network partition is to be
used for DCPS partition/topic combinations matching the
DCPSPartitionTopic attribute within this PartitionMapping element.</p>""" ] ]
            attribute NetworkPartition {
              text
            }
          }*
        }*
      }*
      & [ a:documentation [ xml:lang="en" """
<p>The SSL element allows specifying various parameters related to using
SSL/TLS for DDSI over TCP.</p>""" ] ]
      element SSL {
        [ a:documentation [ xml:lang="en" """
<p>If disabled this allows SSL connections to occur even if an X509
certificate fails verification.</p><p>The default value is:
&quot;true&quot;.</p>""" ] ]
        element CertificateVerification {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>The set of ciphers used by SSL/TLS</p><p>The default value is:
&quot;ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH&quot;.</p>""" ] ]
        element Ciphers {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This enables SSL/TLS for TCP.</p><p>The default value is:
&quot;false&quot;.</p>""" ] ]
        element Enable {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>The SSL/TLS random entropy file name.</p><p>The default value is:
&quot;&quot;.</p>""" ] ]
        element EntropyFile {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>The SSL/TLS key pass phrase for encrypted keys.</p><p>The default
value is: &quot;secret&quot;.</p>""" ] ]
        element KeyPassphrase {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>The SSL/TLS key and certificate store file name. The keystore must be
in PEM format.</p><p>The default value is: &quot;keystore&quot;.</p>""" ] ]
        element KeystoreFile {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>The minimum TLS version that may be negotiated, valid values are 1.2
and 1.3.</p><p>The default value is: &quot;1.3&quot;.</p>""" ] ]
        element MinimumTLSVersion {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This enables the use of self signed X509 certificates.</p><p>The
default value is: &quot;false&quot;.</p>""" ] ]
        element SelfSignedCertificates {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This enables an SSL server checking the X509 certificate of a
connecting client.</p><p>The default value is: &quot;true&quot;.</p>""" ] ]
        element VerifyClient {
          xsd:boolean
        }?
      }*
      & [ a:documentation [ xml:lang="en" """
<p>The Sizing element specifies a variety of configuration settings
dealing with expected system sizes, buffer sizes, &c.</p>""" ] ]
      element Sizing {
        [ a:documentation [ xml:lang="en" """
<p>This element specifies the size of one allocation unit in the receive
buffer. Must be greater than the maximum packet size by a modest amount
(too large packets are dropped). Each allocation is shrunk immediately
after processing a message, or freed straightaway.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;128
KiB&quot;.</p>""" ] ]
        element ReceiveBufferChunkSize {
          memsize
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element sets the size of a single receive buffer. Many receive
buffers may be needed. The minimum workable size a little bit larger than
Sizing/ReceiveBufferChunkSize, and the value used is taken as the
configured value and the actual minimum workable size.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is: &quot;1
MiB&quot;.</p>""" ] ]
        element ReceiveBufferSize {
          memsize
        }?
      }*
      & [ a:documentation [ xml:lang="en" """
<p>The TCP element allows specifying various parameters related to
running DDSI over TCP.</p>""" ] ]
      element TCP {
        [ a:documentation [ xml:lang="en" """
<p>Setting this to true means the unicast addresses in SPDP packets will
be ignored and the peer address from the TCP connection will be used
instead. This may help work around incorrectly advertised addresses when
using TCP.</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element AlwaysUsePeeraddrForUnicast {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element enables the optional TCP transport - deprecated, use
General/Transport instead.</p><p>The default value is:
&quot;default&quot;.</p>""" ] ]
        element Enable {
          ("false"|"true"|"default")
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element enables the TCP_NODELAY socket option, preventing
multiple DDSI messages being sent in the same TCP request. Setting this
option typically optimises latency over throughput.</p><p>The default
value is: &quot;true&quot;.</p>""" ] ]
        element NoDelay {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the TCP port number on which Cyclone DDS
accepts connections. If the port is set it is used in entity locators,
published with DDSI discovery. Dynamically allocated if zero. Disabled if
-1 or not configured. If disabled other DDSI services will not be able to
establish connections with the service, the service can only communicate
by establishing connections to other services.</p><p>The default value
is: &quot;-1&quot;.</p>""" ] ]
        element Port {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the timeout for blocking TCP read operations.
If this timeout expires then the connection is closed.</p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;2 s&quot;.</p>""" ] ]
        element ReadTimeout {
          duration
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element specifies the timeout for blocking TCP write operations.
If this timeout expires then the connection is closed.</p>

<p>The unit must be specified explicitly. Recognised units: ns, us, ms,
s, min, hr, day.</p><p>The default value is: &quot;2 s&quot;.</p>""" ] ]
        element WriteTimeout {
          duration
        }?
      }*
      & [ a:documentation [ xml:lang="en" """
<p>The ThreadPool element allows specifying various parameters related to
using a thread pool to send DDSI messages to multiple unicast addresses
(TCP or UDP).</p>""" ] ]
      element ThreadPool {
        [ a:documentation [ xml:lang="en" """
<p>This element enables the optional thread pool.</p><p>The default value
is: &quot;false&quot;.</p>""" ] ]
        element Enable {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This elements configures the maximum number of threads in the thread
pool.</p><p>The default value is: &quot;8&quot;.</p>""" ] ]
        element ThreadMax {
          xsd:integer
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This elements configures the initial number of threads in the thread
pool.</p><p>The default value is: &quot;4&quot;.</p>""" ] ]
        element Threads {
          xsd:integer
        }?
      }*
      & [ a:documentation [ xml:lang="en" """
<p>This element is used to set thread properties.</p>""" ] ]
      element Threads {
        [ a:documentation [ xml:lang="en" """
<p>This element is used to set thread properties.</p>""" ] ]
        element Thread {
          [ a:documentation [ xml:lang="en" """
<p>The Name of the thread for which properties are being set. The
following threads exist:</p>

<ul><li><i>gc</i>: garbage collector thread involved in deleting
entities;</li>

<li><i>recv</i>: receive thread, taking data from the network and running
the protocol state machine;</li>

<li><i>dq.builtins</i>: delivery thread for DDSI-builtin data, primarily
for discovery;</li>

<li><i>lease</i>: DDSI liveliness monitoring;</li>

<li><i>tev</i>: general timed-event handling, retransmits and
discovery;</li>

<li><i>fsm</i>: finite state machine thread for handling security
handshake;</li>

<li><i>xmit.CHAN</i>: transmit thread for channel CHAN;</li>

<li><i>dq.CHAN</i>: delivery thread for channel CHAN;</li>

<li><i>tev.CHAN</i>: timed-event thread for channel CHAN.</li></ul>""" ] ]
          attribute Name {
            text
          }
          & [ a:documentation [ xml:lang="en" """
<p>This element configures the scheduling properties of the thread.</p>""" ] ]
          element Scheduling {
            [ a:documentation [ xml:lang="en" """
<p>This element specifies the thread scheduling class (<i>realtime</i>,
<i>timeshare</i> or <i>default</i>). The user may need special privileges
from the underlying operating system to be able to assign some of the
privileged scheduling classes.</p><p>The default value is:
&quot;default&quot;.</p>""" ] ]
            element Class {
              ("realtime"|"timeshare"|"default")
            }?
            & [ a:documentation [ xml:lang="en" """
<p>This element specifies the thread priority (decimal integer or
<i>default</i>). Only priorities that are supported by the underlying
operating system can be assigned to this element. The user may need
special privileges from the underlying operating system to be able to
assign some of the privileged priorities.</p><p>The default value is:
&quot;default&quot;.</p>""" ] ]
            element Priority {
              text
            }?
          }?
          & [ a:documentation [ xml:lang="en" """
<p>This element configures the stack size for this thread. The default
value <i>default</i> leaves the stack size at the operating system
default.</p>

<p>The unit must be specified explicitly. Recognised units: B (bytes), kB
& KiB (2<sup>10</sup> bytes), MB & MiB (2<sup>20</sup> bytes), GB & GiB
(2<sup>30</sup> bytes).</p><p>The default value is:
&quot;default&quot;.</p>""" ] ]
          element StackSize {
            memsize
          }?
        }*
      }*
      & [ a:documentation [ xml:lang="en" """
<p>The Tracing element controls the amount and type of information that
is written into the tracing log by the DDSI service. This is useful to
track the DDSI service during application development.</p>""" ] ]
      element Tracing {
        [ a:documentation [ xml:lang="en" """
<p>This option specifies whether the output is to be appended to an
existing log file. The default is to create a new log file each time,
which is generally the best option if a detailed log is
generated.</p><p>The default value is: &quot;false&quot;.</p>""" ] ]
        element AppendToFile {
          xsd:boolean
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element enables individual logging categories. These are enabled
in addition to those enabled by Tracing/Verbosity. Recognised categories
are:</p>

<ul><li><i>fatal</i>: all fatal errors, errors causing immediate
termination</li>

<li><i>error</i>: failures probably impacting correctness but not
necessarily causing immediate termination</li>

<li><i>warning</i>: abnormal situations that will likely not impact
correctness</li>

<li><i>config</i>: full dump of the configuration</li>

<li><i>info</i>: general informational notices</li>

<li><i>discovery</i>: all discovery activity</li>

<li><i>data</i>: include data content of samples in traces</li>

<li><i>radmin</i>: receive buffer administration</li>

<li><i>timing</i>: periodic reporting of CPU loads per thread</li>

<li><i>traffic</i>: periodic reporting of total outgoing data</li>

<li><i>whc</i>: tracing of writer history cache changes</li>

<li><i>tcp</i>: tracing of TCP-specific activity</li>

<li><i>topic</i>: tracing of topic definitions</li>

<li>>i>plist</i>: tracing of discovery parameter list interpretation</li>
</ul>

<p>In addition, there is the keyword <i>trace</i> that enables all but
<i>radmin</i>, <i>topic</i>, <i>plist</i> and <i>whc</i></p>.

<p>The categorisation of tracing output is incomplete and hence most of
the verbosity levels and categories are not of much use in the current
release. This is an ongoing process and here we describe the target
situation rather than the current situation. Currently, the most useful
is <i>trace</i>.</p><p>The default value is: &quot;&quot;.</p>""" ] ]
        element Category {
          xsd:token { pattern = "((fatal|error|warning|info|config|discovery|data|radmin|timing|traffic|topic|tcp|plist|whc|throttle|rhc|content|trace)(,(fatal|error|warning|info|config|discovery|data|radmin|timing|traffic|topic|tcp|plist|whc|throttle|rhc|content|trace))*)|" }
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This option specifies where the logging is printed to. Note that
<i>stdout</i> and <i>stderr</i> are treated as special values,
representing "standard out" and "standard error" respectively. No file is
created unless logging categories are enabled using the Tracing/Verbosity
or Tracing/EnabledCategory settings.</p><p>The default value is:
&quot;cyclonedds.log&quot;.</p>""" ] ]
        element OutputFile {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This option specifies the file to which received and sent packets will
be logged in the "pcap" format suitable for analysis using common
networking tools, such as WireShark. IP and UDP headers are ficitious, in
particular the destination address of received packets. The TTL may be
used to distinguish between sent and received packets: it is 255 for sent
packets and 128 for received ones. Currently IPv4 only.</p><p>The default
value is: &quot;&quot;.</p>""" ] ]
        element PacketCaptureFile {
          text
        }?
        & [ a:documentation [ xml:lang="en" """
<p>This element enables standard groups of categories, based on a desired
verbosity level. This is in addition to the categories enabled by the
Tracing/Category setting. Recognised verbosity levels and the categories
they map to are:</p>

<ul><li><i>none</i>: no Cyclone DDS log</li>

<li><i>severe</i>: error and fatal</li>

<li><i>warning</i>: <i>severe</i> + warning</li>

<li><i>info</i>: <i>warning</i> + info</li>

<li><i>config</i>: <i>info</i> + config</li>

<li><i>fine</i>: <i>config</i> + discovery</li>

<li><i>finer</i>: <i>fine</i> + traffic and timing</li>

<li><i>finest</i>: <i>finer</i> + trace</li></ul>

<p>While <i>none</i> prevents any message from being written to a Cyclone
DDS log file.</p>

<p>The categorisation of tracing output is incomplete and hence most of
the verbosity levels and categories are not of much use in the current
release. This is an ongoing process and here we describe the target
situation rather than the current situation. Currently, the most useful
verbosity levels are <i>config</i>, <i>fine</i> and
<i>finest</i>.</p><p>The default value is: &quot;none&quot;.</p>""" ] ]
        element Verbosity {
          ("finest"|"finer"|"fine"|"config"|"info"|"warning"|"severe"|"none")
        }?
      }*
    }*
  }
  bandwidth = xsd:token { pattern = "0|(\d+(\.\d*)?([Ee][\-+]?\d+)?|\.\d+([Ee][\-+]?\d+)?) *([kMG]i?)?[Bb][p/]s" }
  duration = xsd:token { pattern = "0|(\d+(\.\d*)?([Ee][\-+]?\d+)?|\.\d+([Ee][\-+]?\d+)?) *([num]?s|min|hr|day)" }
  duration_inf = xsd:token { pattern = "inf|0|(\d+(\.\d*)?([Ee][\-+]?\d+)?|\.\d+([Ee][\-+]?\d+)?) *([num]?s|min|hr|day)" }
  memsize = xsd:token { pattern = "0|(\d+(\.\d*)?([Ee][\-+]?\d+)?|\.\d+([Ee][\-+]?\d+)?) *([kMG]i?)?B" }
}