snmp agent : how does it work

[Nelly PISON]

Hello,

I have to realize an SNMP agent on a board with ecos and  the freeBSD 
TCP/IP stack that already work fine

1 - does the ecos agent snmp work without problem ?

2 - I want to manage only 4 data to be read by a manager. I think it is 
possible to do so without creating necessarily  a MIB.
So in the user init function I want to declare them: which function can 
be use?
 I look for  an equivalent to netsnmp_register_int_instance() that I 
found in an example about SNMP
But this function doesn't exist in the ecos packages .

Thanks for any response
Nelly PISON