NonStop S-Series Planning and Configuration Guide (G06.29+)

Terms and Concepts
HP NonStop S-Series Planning and Configuration Guide—523303-021
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ServerNet Link
ServerNet Link
A ServerNet link consists of two unidirectional point-to-point communication paths, one
in each direction.
A ServerNet link connects a ServerNet router to:
•
A ServerNet node
•
Another ServerNet router
ServerNet Node
A ServerNet node is a system in a ServerNet cluster. ServerNet nodes send and
receive ServerNet packets.
ServerNet Packet
ServerNet packets are sent and received by ServerNet nodes. A ServerNet packet
consists of a header, an address field, a 0-to-64-byte data field, and a 32-bit cyclic
redundancy check (CRC) checksum covering the entire packet. The header contains
fields for control, destination, and source fields to identify the processor or I/O device
transmitting and receiving the packet. The address field contains the memory address
where the data in the packet will be loaded.
ServerNet packets negotiate the network using a technique called wormhole routing.
ServerNet Router
A ServerNet router routes ServerNet packets along ServerNet links.
The router 1 used in NonStop S700, S7000, S7400, S70000, and S72000 servers is a
six-port crossbar switch that can simultaneously connect any input with any output.
The NonStop S7600, S74000, and later servers use the router 2, which is a twelve-port
crossbar switch.