FIX Performance Session Layer (FIXP) is a lightweight protocol that describes how to establish and maintain a communication session between two endpoints. Its main goal is to provide a reliable and highly efficient exchange of financial messages over a variety of transports.
FIXP is developed by the High-Performance Working Group of the FIX Trading Community.
The main Features of FIXP are:
- Low overhead session layer
- No restriction on the application layer (no session-level fields are required in application messages)
- Encoding independent, message binary wire format (for example, SBE, Google Protocol Buffer) is agreed between counterparties
- Transport independent (both stream and datagram protocols are supported)
- Negotiable message delivery guarantees
FIXP does not specify security features, counter-parties agree on user authentication techniques.
A message framing protocol (for example, “Simple Open Framing Header”) may be used to delimit messages by agreement between counter-parties.
Message Flow Types:
A message flow is a stream of application messages in one direction.
FIXP supports configurable delivery guarantees for each flow:
- Recoverable: exactly-once message delivery. If message gaps are detected, then missed messages may be recovered by retransmission.
- Idempotent: at-most-once delivery. If message gaps are detected, the sender is notified, but recovery is under control of the application.
- Unsequenced: no delivery guarantees (best-effort).
- None: one-way flow of messages. No application messages should be sent in one direction of the session.
A bi-directional session may have asymmetrical message flows (e.g., the exchange flow could be Recoverable, and the client flow could be Idempotent).
Each FIXP session must be identified by a unique Session ID encoded as a UUID version 4 (RFC 4122) assigned by the client (for example, f81d4fae-7dec-11d0-a765-00a0c91e6bf6).
A session identifier must be unique for all time.
A FIXP session is established between counter-parties and lasts until message flows between them are complete.
Timing for session start and end are agreed between counter-party.
A logical FIXP session is identified by a Session ID and can span over several sequential transport connections. When an existing session is re-established, its original Session ID is used, and messages that were lost during the disconnect may be recovered.
Sequence numbering is used for ordered delivery and message recovery. Only application messages are sequenced. A session-level message is used to start a sequenced flow of application messages.
OnixS Products supporting FIXP:
In this specific context, OnixS supports FIXP in the OnixS directConnect: CME iLink 3 Binary Order Entry Handler SDKs.