NonStop S-Series Server Description Manual (G06.24+)

Principles of System Operation

HP NonStop S-Series Server Description Manual—520331-003

2-7

ServerNet Packets

Figure 2-3. A ServerNet Transaction Has Both a Request and a Response Packet

ServerNet Packet Types

HAC

HDC

HDCA

Read Request

Read Response

Write Request

Write Response

ServerNet Packet Layout

H 8-Byte Header

20-Bit Destination ServerNet ID (DID)

20-Bit Source ServerNet ID (SID)

4-Bit Transaction Type

8-Bit Data Length

4-Bit Transaction ID

1-Bit Primary/Alternate Path

1-Bit Acknowledge/Negative Acknowledge

1-Bit Request/Response

5 Bits Reserved

A 4-Byte ServerNet Address

D 0-Byte to 64-Byte Data

C 4-Byte Cyclic Redundancy Check (CRC) Code

on preceding fields: H, (A), (D)

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