[This message was posted by Hei Chan of N/A <[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/7b428f5e - PLEASE DO NOT 
REPLY BY MAIL.]

Thanks for your quick reply!

> Hi,
> 
> Frame length is a feature that must be agreed on bi-laterally. There is
> nothing in the wire data that tells you it is there and it is currently
> not used in any impl as far as I know.
> 
> Frame length is optional and it was included in the std to simplify
> parsing for those who wanted to build a more naive FAST decoder over
> TCP. Depending on how you implement your decoder you may or may not have
> use for a frame length. A side-effect of using the frame length
> construct is that you can skip over a message that you don't recognize.
> 
> This is not without complications as you must make sure that the
> previous value state for your field encoding operations remain intact.
> So, even if you don't know how to decode the message you have to know
> that there are no dependencies to messages that you do know and
> therefore can parse.
> 
> The rules and best practices around frame length are still somewhat
> untested, so proceed with caution.
> 
> I recommend that you don't use frame length unless you believe you have
> a strong reason to use it.
> 
> HTH, Rolf
> 
> > Hi,
> >
> > I read http://www.fixprotocol.org/documents/2301/A%20Basic%20Guide%20to-
> > %20FAST%20v1.0.pdf.
> >
> > I am confused about the frame length field mentioned on page 17.
> >
> > I am sending an encoded message over TCP (socket). So do I need to
> > prefix the message with the length of the message?
> >
> > If yes, how does the receiver know that it is a new message (given
> > that date transferred over TCP is just a byte stream)?
> >
> > If it has been asked, please give me a pointer. (A little bit hard to
> > use the search function here...:()
> >
> > Thanks in advance!


[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.


Reply via email to