Login Request Message Fields
A LoginRequest message must be sent as the first message upon connection.
The message includes a repeating group starting with field UnitNumber which repeats NumberOfUnits times. This can be used to specify the last consumed sequence numbers per matching unit received by the member. Cboe uses these sequence numbers to determine what outbound (Cboe to Member) traffic, if any, was missed by the member. If NumberOfUnits= 0, it is assumed the member has not received any messages (e.g., start of day).
The member does not need to include a sequence number for a unit if they have never received messages from it. If the member wishes to send a value for the unit anyway, 0 is the only allowed value for UnitSequence .
| Field Name | Offset | Length | Data Type | Description |
|---|---|---|---|---|
| StartOfMessage | 0 | 2 | Binary | 0xB0 0xE3 (58288) |
| MessageLength | 2 | 2 | Binary | |
| MessageType | 4 | 2 | Binary | 0x0001 (1) |
| MatchingUnit | 6 | 1 | Binary | Must be zero |
| Reserved | 7 | 1 | Binary | Must be zero |
| SequenceNumber | 8 | 4 | Binary | Must be zero |
| SessionId | 12 | 4 | AlphaNumeric | Session Id as supplied by Cboe |
| SessionSubId | 16 | 4 | AlphaNumeric | Session Sub Id as supplied by Cboe |
| Password | 20 | 10 | AlphaNumeric | The password associated with the SessionId and SessionSubId. |
| ReplayInstruction | 30 | 1 | Text |
|
| NumberOfUnits | 31 | 1 | Binary | The number (possibly 0) of unit/sequence pairs to follow, one per unit from which the member has received messages over this port. The value must be 0 or 1 for unitized BOE ports. |
| →UnitNumber | 32 | 1 | Binary | A unit number. This must be the unit number of the port. |
| →UnitSequence | 33 | 4 | Binary | Last received sequence number for the unit. |