[This message was posted by Guangbin Xu of SSE <[email protected]> to the "FAST Protocol" discussion forum at http://fixprotocol.org/discuss/46. You can reply to it on-line at http://fixprotocol.org/discuss/read/0dc81b64 - PLEASE DO NOT REPLY BY MAIL.]
Thanks for your explanation. It’s clear now. I originally thought FAST SCP is a total counterpart to FIXT after reading the “FIX Using the FAST Session Control Protocol (SCP)” part of the “transport independence framework” section of FIX5.0. Now according to my understanding, the FIX/FAST protocol hierarchy is not so clear as OSI reference model. Although both of them are dealing with the OSI’s presentation layer’s issue, however, the functionalities are different, and can be used at the different layer. Meanwhile, the semantics is somewhat crossing-layer. > When using FIX over FAST you can think of FAST as just an alternative > encoding to the classic tag=value (or FIXML) encoding. This means that > FAST doesn't imply anything about the actual type of the messages sent. > > Most things in the FIX message model still needs to be present even if > FAST is used as the low level encoding. This includes the FIX session > messages. I say most since some fields in FIX are really artifacts of > the tag=value encoding. Fields like BeginString, MsgType, BodyLen, > Checksum etc either have other corresponding mechanisms in FAST or > aren't applicable at all. > > FAST SCP and FIXT are not really related and have different purposes. > FAST SCP provides handshake, reset and termination of communication at > the FAST level. Additionally, SCP Level 3 provides means for exchanging > FAST templates dynamically. > > FIXT on the other hand provides means for authorization and FIX message > sequencing and recovery. > > /David > > > > As we all know, FIX5.0 introduces the concept of TI (transportation > > Independence). I'm trying to implement FIX over FAST and want all > > messages to be numbered and sequenced in the FIX4.1 way, which I think > > is easier for in-order message recovery. So the FIXT seems a more > > proper solution of session control. However, I want FIX over FAST. The > > problem then is: are there incompatible aspects and tricky things I > > have to handle there? What is the major discrepancy between FAST SCP > > and FIXT? [You can unsubscribe from this discussion group by sending a message to mailto:[email protected]] --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Financial Information eXchange" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/fix-protocol?hl=en -~----------~----~----~----~------~----~------~--~---
