InfiniBand Network Architecture

Basic MAD Contents

Table 28-1 on page 783 illustrates the basic format of a MAD. The first six dwords (24 bytes) are referred to as the base-MAD header and is the same for all MADs. The fields of the base MAD header are defined in Table 28-2 on page 783.

Table 28-1. Base MAD Format

Dword		Byte 0	Byte 1	Byte 2	Byte 3
0	Base MAD Header	Base Version = 01h	Management Class (see Table 28-3 on page 785)	Class Version = 01h	R	Method (see Table 28-4 on page 786)
1		Status (see Table 27-2 on page 776)		Only used in directed-route SMP (see Table 28-6 on page 789)
2		Transaction ID
3
4		AttributeID		Reserved
5		AttributeModifier
6–63		Data field. Contents is defined by the type of MAD.

Table 28-2. Definition of Base MAD Header Fields

Field	Length (in bits)	Description
Base Version	8	Version ...