InfiniBand Network Architecture

Additional Reference Material

Raw Packet Length

Raw packets do not include the IBA transport headers, so a raw datagram packet may have a payload greater than the PMTU. Table 21-1 on this page summarizes the maximum payload (and corresponding value for LRH:PktLen) for the two raw datagram types. PktLen indicates the payload size as a number of dwords, so the packet payload must always be divisible by four. If the encapsulated payload size is not a multiple of four, the payload must be padded so as to be a multiple of four. The smallest allowed value for Packet Length is five (5 X 4 = 20 bytes) including the LRH (which is eight bytes in length). The 124-byte maximum packet header/CRC byte count does not include the VCRC.

• The largest possible raw ...