Imported from previous forum
Hi,
I have three queries here :
- Vol. 6 (FIX DATA DICTIONARY) for FIX 4.3 , does not mention the maximum lengths of the values. By value I mean Value in format -"Tag=Value".
Does this mean that there is no specified maximum lenghts of these values?
-
Is such a data dictionary available for FIX versions 4.0 and 4.1 also.
-
Are the various FIX versions backward compatible ? To be specific is FIX version 4.3 backward compatible with FIX versions 4.0 or 4.1.
Rgds,
manisha
[ original email was from Ryan Pierce - rpierce@taltrade.com ]
> 1) Vol. 6 (FIX DATA DICTIONARY) for FIX 4.3 , does not mention the maximum lengths of the values. By value I mean Value in format -"Tag=Value".
> Does this mean that there is no specified maximum lenghts of these values?
Yes. No limits are defined on field lengths. That is something that needs to be addressed on a per-counterparty basis.
In the past, FIX has specified arbitrary limits (maximum number of messages per session, maximum message length), firms have found they limit their business, and so the limits have been removed in later protocol versions.
> 2) Is such a data dictionary available for FIX versions 4.0 and 4.1 also.
All versions of the FIX Protocol define fields and messages. So, in one sense, all FIX Protocol versions are data dictionaries. FIX 4.3 just re-ordered things, and formalized the practice of common component blocks.
> 3) Are the various FIX versions backward compatible ? To be specific is FIX version 4.3 backward compatible with FIX versions 4.0 or 4.1.
No. In fact, given a FIX Execution Report message, you often cannot statelessly convert it into a FIX message of another version. Of the conversions:
4.0 -> 4.1 - NO (LeavesQty, ExecType, etc.)
4.1 -> 4.0 - NO (ExecID string -> integer problem)
4.1 -> 4.2 - NO (Separate Pending Cancel/Replace)
4.2 -> 4.1 - MAYBE
4.2 -> 4.3 - MAYBE
4.3 -> 4.2 - NO (4.3 has no OrdStatus=Replaced)
Now if you can introduce a state machine in the middle, mapping between all FIX versions is possible.