Expand Configuration and Management Manual (H06.03+)

Expand Overview

Expand Configuration and Management Manual—529522-002

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Systems Network Architecture (SNA) Networks

SNA was developed by IBM for connecting IBM systems and networks. Expand-over-

SNA connections are provided with the HP SNAX/Advanced Peer Networking

(SNAX/APN) product. The Expand subsystem uses the NETNAM protocol to

communicate with the SNAX/APN line-handler process.

Internet Protocol (IP) Networks

An IP network adheres to the Internet Protocol—a computer-industry standard

protocol. An ever-increasing number of public and private networks are based on IP,

including the Internet itself. Expand-over-IP connections are provided by the NonStop

TCP/IP products.

Asynchronous Transfer Mode (ATM) Networks

ATM is a cell-switching and multiplexing technology that combines the benefits of

circuit switching (constant transmission delay and guaranteed capacity) with those of

packet switching (flexibility and efficiency for intermittent traffic). Expand-over-ATM

connections are provided with the ATM subsystem.

ServerNet Clusters

ServerNet Clusters use Expand to provide a high-speed interconnect between servers

over a limited geographic range. Three network topologies are supported: the star,

split-star, and tri-star topologies. The star topology supports up to eight nodes. The

split-star topology supports up to 16 nodes. The tri-star topology supports up to 24

nodes

The 16-node configuration is split between two NonStop cluster switches per external

fabric in what is known as a split-star topology and the 24-node configuration is split

between three cluster switches per external fabric in what is known as a tri-star

topology. Using single-mode fiber-optic cables to link the two centers of the split-star

and the three centers of the tri-star allows a greater distance (up to 1 kilometer)

between the cluster switches and their connected nodes.

For detailed topology information, see Section 4, Planning for ServerNet Clusters.

An Integrity NonStop NS-series server cannot participate in more than one ServerNet

cluster.