dsplink...buffer pool and sma pool

Hi Everybody,
whats the difference between buffer pool and sma pool as given in dsplink ring io example? I am confused about the fixed bufer size option in sma pool, not sure what it implies. Can anybody clarify about it and explain a bit how to use it? In buffer pool, I am seeing that the struct BUFPOOL_Params

typedef struct BUFPOOL_Params_tag {
    Uint32     numBufObjs ;
    Uint32 *   bufSizes ;
    Uint32 *   numBuffers ;
    Uint16     segId ;
} BUFPOOL_Params ;

what to give it for segId if I want to use the buffer pool?

Thanks and Regards,
zix

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