Setting	Description	Default value
Acceptor.SendLogoutOnInvalidLogon	Option to send a Logout message, before dropping the telecommunication link in reply on an invalid logon attempt (e.g. received an initial Logon message when a valid FIX Connection is already underway for the same SenderCompID, TargetCompID and FIX Version).	false
AsyncFileBasedStorageQueueMaxSize	Specifies the log queue maximum size of the asynchronous session storage.	numeric_limits<unsigned>::max() (Unlimited)
AsyncFileBasedStorageThreadAffinity	Specifies the CPU index(es) for affinity of the asynchronous session storage threads. Symbol ',' is used as the cpu index delimiter. This affinity will be used by all asynchronous session storages of all sessions.	Empty
Connection.MessageGrouping	The number of messages that should be written to the outgoing TCP buffer together. Value 0 means default grouping - the messages will be sent ASAP, and pending messages (if any) will be grouped till reaching of TCP buffer size. Value 1 means the messages will be sent ASAP and never will be grouped. Value 2 (or greater) means the messages will be sent ASAP and pending messages will be grouped maximum by 2 (or greater).	0
ThreadingModel	The way in which the Engine will work with sockets.	Default (OnixS::FIX::ThreadingModel::Default)
Connection.ReceiveBufferSize	The size of the buffer allocated to the FIX connection for receiving data (SO_RCVBUF). If the setting is set to '-1', then the default operating system value is used.	-1
Connection.ReceiveSpinningTimeout	Spinning timeout for data receiving.	0
Connection.SendSpinningTimeout	Spinning timeout for data sending.	0
Connection.SendBufferSize	The size of the buffer is allocated to the FIX connection for sending data (SO_SNDBUF). If the setting is set to '-1', then the default operating system value is used.	-1
Connection.TcpNoDelayOption	Option to improve latency at the expense of message throughput (TCP_NODELAY).	true
DictionaryFile	Specify path(s) to XML file(s) with the description of FIX Dictionary(s). More than one file could be specified. The symbol '\|' is used as the file name delimiter.	Empty
DialectString	Specifies the plain text string with a description of the FIX dialect.	Empty
ExpectedIncomingMessageSize	The value represents an average FIX message size that is expected to be received by the session during the lifetime. It is used as a hint for the optimization of the deserialization of large FIX messages with a lot of repeating groups.	102400
FileBasedStorageSegmentSize	Segment size for the file-based session storage.	0
FirstLogonTimeout	Timeout (in seconds) between an incoming TCP connection is detected and the first Logon message is received.	30
IgnoreFileBasedStorageIntegrityErrors	Behavior when File-Based Storage errors are detected. If 'true' creates new session storage when errors are detected. If 'false' throws exception and prevents session against creating.	false
LicenseFile	Specifies the path to the license file. Deprecated since version 2.76.1.0 .	OnixS.Cpp.FIX.Engine.lic
LicenseStore	Specifies the path to the folder that contains license file(s).</td	.
LicenseString	Specifies the string of license content.	Empty
LicenseAlertingDaysBeforeExpiration	Specifies the number of days to alert before the license expiration. If the amount of remaining license days is less or equal to this number then the warning will be reported to the FIX Engine's log and IEngineListener::onWarning callback will be invoked.	0 (No alerting)
ListenPort	FIX Engine listens on this port for incoming connections: If '0', then only session-initiators can be created. If '-1', then the telecommunication level is disabled, and only a message parsing/assembling can be used. Comma delimited list could be used to specify more than one listen port.	0
LocalInterfaces	Specifies local interfaces where engine listen for incoming connections. Each local interface specification could specify the local IP address and port. For instance "localhost" and "192.168.0.1:4501" are valid values. When a local interface specification contains the same port as specified at listenPort settings the listening appears only on the interface and port specified at localInterface setting.	Empty
Log.CreateEngineLogFile	Option to create the FIX Engine log file.	true
Log.Directory	Inbound and outbound messages, session's state data and the FIX Engine log file (`FixEngineLog.txt`) are stored in this directory.	MsgStorage
Log.BeforeSending	Option to switch on/off logging of outbound messages before/after sending.	true
LogFileName	Specifies the FIX Engine log file name.	FixEngineLog.txt
LocalTimeUsage	Specifies the usage of local time in FIX Engine events and log files.	false
Log.InboundMessages	Option to log inbound messages.	true
Log.OutboundMessages	Option to log outbound messages.	true
ProcessDeliverToCompID	Option to process the DeliverToCompID (tag 128) flag.	false
ReasonableTransmissionTime	The reasonable transmission time as % from HeartBtInt value. When either end of the connection has not received any data for (HeartBtInt * (100 + ReasonableTransmissionTime)/100) seconds, it will transmit a Test Request message. If there is still no Heartbeat message received after (HeartBtInt * (100 + ReasonableTransmissionTime)/100) seconds, then the connection should be considered lost, and a corrective action is initiated.	20
Reconnect.Attempts	Number of attempts to restore the FIX connection.	3
Reconnect.Interval	The time interval between the attempts to restore the FIX connection (in seconds).	180
Resending.QueueSize	Number of sent messages that are available for resending on counterparty's Resend Request <2> message.	1000
Resending.ResendRequestMaximumRange	The maximum number of messages to be requested in one Resend Request (MsgType=2) message.	0 (Unlimited)
ReportNewMessagesWhileWaitingForMissedMessages	When the message gap is detected the Resend Request <2> FIX Message is sent and Session state is changed to "AwaitReplyOnResendRequest". By default in this state, the incoming new messages (without the PossDupFlag (tag #43) flag) are ignored because we expect them to be re-sent later again with the PossDupFlag flag. This property allows to change this behavior and report the new messages anyway. In this mode messages could be reported out of the original order: e.g. MsgSeqNum could be: 3 (original), 4 (original), 2 (PossDupFlag='Y'), 3 (PossDupFlag='Y'), 4 (PossDupFlag='Y') and some messages could be received two times: first time without PossDupFlag='Y' and second time - with this flag.	false
Session.SendLogoutOnException	Option to send the Logout message before dropping the telecommunication link, in case of Exception, during the processing of incoming FIX message.	false
SpecifyApplVerIdField	Option to specify ApplVerID(1128) tag in all application FIX messages when a FIX protocol version FIX 5.0 and above is used	true
SpecifyLastMsgSeqNumProcessed	Option to specify the LastMsgSeqNumProcessed (tag=369) field on every message sent. Useful for detecting a backlog with a counterparty.	false
SSL.CertificateFile	The path to the TLS/SSL certificate file in (Privacy Enhanced Mail) Base64 encoded (.pem) format. This file can refer to a certificate chain file with multiple CA certificates.	Empty
SSL.ListenPort	FIX Engine listens on this port for incoming TLS/SSL connections: If it is set to '0', then only TLS/SSL-based session-initiators can be created. If it is set to '-1', then the TLS/SSL encryption is disabled. Comma delimited list could be used to specify more than one TLS/SSL listen port.	0
SSL.LocalInterfaces	Specifies local interfaces where engine listen for incoming TLS/SSL connections.	Empty
SSL.PrivateKeyFile	The path to the TLS/SSL private key file in (Privacy Enhanced Mail) Base64 encoded (.pem) format.	Empty
SSL.PrivateKeyPassword	The password to load private keys that are protected by a password.	Empty
SSL.VerifyPeer	Option to request counterparty certificates and perform the certificate verification.	false
SSL.ClientSni	Option to enable the client-side TLS/SNI extension (Server Name Indication). if it is empty, then SNI extension is not enabled. if it is set to "*" (wildcard), then SNI extensions will be enabled and server name will be the same as the connection URL (domain name). other values enable SNI extension and will be used as a server name.	Empty
SSL.CaFile	The path to the trusted certification authority certificate file in (Privacy Enhanced Mail) Base64 encoded (.pem) format.	Empty
SSL.MinProtocolVersion	The minimal SSL/TLS protocol version that will be declared during the SSL/TLS handshake.	0 (OnixS::FIX::SslProtocolMinMaxVersion::LowestHighest)
SSL.MaxProtocolVersion	The maximal SSL/TLS protocol version that will be declared during the SSL/TLS handshake.	0 (OnixS::FIX::SslProtocolMinMaxVersion::LowestHighest)
ServiceThreadAffinity	Specifies the CPU index(es) for affinity of the Engine service threads. Symbol ',' is used as the cpu index delimiter.	Empty
ServiceThreadPriority	Specifies the priority of the Engine service threads.	255 (OnixS::FIX::Session::UndefinedPriorityAndPolicy - OS default value is used)
ServiceThreadPolicy	Specifies the policy of the Engine service threads.	255 (OnixS::FIX::Session::UndefinedPriorityAndPolicy - OS default value is used)
ScrambleLogonFields	Specifies scramble fields in the Logon message, in the session storage and FIX Engine log, for security reasons. Symbol ',' is used as the tag number delimiter.	Empty
SendQueueMaxSize	The send queue maximum size in bytes.	536870912 (0.5 Gb)
ThreadPoolSize	The size of the shared thread pool that uses in the thread pool connection mode.	0
Validate.EmptyFieldValues	Option to validate the empty field values of FIX messages in accordance with the FIX protocol or its FIX Dictionary.	false
Validate.FieldValues	Option to validate the field values of FIX messages in accordance with the FIX protocol or its FIX Dictionary.	false
Validate.RepeatingGroupEntryCount	Option to validate that the declared number of FIX Repeating Groups instances is equal to the actual one.	true
Validate.RepeatingGroupLeadingTag	Option to validate that FIX Repeating Groups entry starts with the required dictionary leading tag.	false
Validate.RequiredFields	Option to validate the presence of required fields in inbound and outbound messages.	false
Validate.UnknownFields	Option to validate the presence of unknown fields (fields that do not belong to the message in accordance with the FIX protocol or its FIX Dictionary.	false
Validate.UnknownMessages	Option to validate the presence of unknown FIX messages (messages that do not belong to the message in accordance with the FIX protocol or its FIX Dictionary).	false
Validate.DuplicatedField	Option to validate the presence of fields which appears more than once.	false
Validate.Checksum	Option to validate the checksum of incoming messages.	false
UseSpinLock	Option to use a spinlock mutex instead of the standard one.	false