what is SSID and SFID in OFTP2

 In OFTP (Odette File Transfer Protocol), which is commonly used for B2B data exchange in automotive and manufacturing industries, SSID and SFID are two key messages that are part of the OFTP session management.

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1. SSID – Start Session IDentification

• Purpose: Initiates the OFTP session between two trading partners.

• Direction: Sent by the initiator (client) to the responder (server).

• Contents: Includes session parameters such as:

  • SSID code (SSID)

  • OFTP version (e.g., 1.3, 2.0)

  • Sender and receiver SFIDs (OFTP identifiers)

  • Password/authentication info

  • Compression and encryption support

  • Restart capability

  • File format and character set support

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2. SFID – Start File IDentification

• Purpose: Marks the beginning of a file transfer within an active OFTP session.

• Direction: Sent before sending a file's data.

• Contents: Includes metadata like:

  • File name

  • File format and type (text, binary, etc.)

  • File size

  • Destination OFTP ID

  • Originator and recipient information

  • Security settings (if applicable)

  • Dataset identification

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Here’s an example flow of an OFTP session, including the SSID and SFID segments, followed by a visual diagram and example content for each message:

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✅ OFTP Basic Session Flow (Simplified)

Initiator                                 Responder
   |                                           |
   |------------ SSID (Start Session) -------->|
   |                                           |
   |<----------- SSID Response (SSRP) ---------|
   |                                           |
   |-------- SFID (Start File Header) -------->|
   |                                           |
   |-------- File Data (multiple records) ---->|
   |                                           |
   |------------ EFID (End File ID) ---------->|
   |                                           |
   |<------- EERP (End to End Response) -------|
   |                                           |
   |-------------- SFID (next file) ---------->|
   |                                           |
   |------------------------------------------>|
   |------------ SFID / EFID / EERP ---------->|
   |                                           |
   |------------- SFNA (Session End) --------->|

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🛡️ Example SSID (Start Session Identification)

Field	Example Value	Description
Record ID	SSID	Message type
Protocol Level	20	OFTP protocol version (e.g., 20 for 2.0)
Sender SFID	PARTNERA	Sender’s OFTP ID
Receiver SFID	PARTNERB	Receiver’s OFTP ID
Password	mypassword	Authentication info
Encryption Supported	Y	Y = Supported, N = Not supported
Compression Supported	Y	Y = Supported, N = Not supported
Restart Supported	Y	Restart capability
Character Set	UNOC	Character encoding

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📂 Example SFID (Start File Identification)

Field	Example Value	Description
Record ID	SFID	Message type
File Name	ORDERS.DAT	File name
Destination SFID	PARTNERB	Final recipient OFTP ID
Originator SFID	PARTNERA	Sender’s OFTP ID
File Format	TXT	TXT (Text) / BIN (Binary)
File Size	00001234	File size in bytes
Date	250711	File creation date (YYMMDD)
Time	153000	File creation time (HHMMSS)
Compression	N	N = No compression, Y = Compressed
Encryption	N	N = Not encrypted, Y = Encrypted
Restart Possible	Y	Restart capability

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🔍 Session Flow Diagram

+----------------+                                    +----------------+
| Initiator      |                                    | Responder      |
| (OFTP Client)  |                                    | (OFTP Server)  |
+----------------+                                    +----------------+
        |                                                    |
        | ----------- SSID (session initiation) ------------> |
        |                                                    |
        | <---------- SSRP (session response) --------------- |
        |                                                    |
        | ----------- SFID (file start) -------------------> |
        | ----------- File Data ---------------------------> |
        | ----------- EFID (file end) ---------------------> |
        | <---------- EERP (file received) ----------------- |
        |                                                    |
        | ----------- SFNA (end session) ------------------> |

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