Should SASL_MAXOUTBUF be subject of negotiation?

[MKondrin]

Dear SASL users and developers!

Should sasl_getprop(conn,SASL_MAXBUF,&x) return th same x on client and 
server if the security layer is negotiated? But after authentication it 
returns the value of secprops.maxbufsize (which can of course be 
different on client and server) installed before with sasl_setprop(conn, 
SASL_SEC_PROPS, &secprops). Does this mean I have missed some steps in 
SASL negotiation? I use cyrus-sasl-2.1.21.

Thank you in advance.

M.Kondrin