Networking Concepts

Network Environment Design Considerations

use a Point-to-Point network if the distance between some nodes on the network will be greater than the maximum distance allowed between nodes on a LAN. Bridges, hubs and routers are commonly implemented to extend LANs.

FDDI networks also offer greater distances than LAN, Token Ring, 100VG-AnyLAN, or 100Base-T networks. FDDI networks can be up to 200 kilometers in length, with nodes up to 2 kilometers apart.

If you need to connect nodes that are geographically distant (for example, HP e3000s located in different cities) you might choose to connect them via a dial link. For NS dial links, you can use the Point-to-Point 3000/iX Network Link.

Finally, if you need to use satellite transmission because of the large geographical distance between nodes, or if you need to have access to other nodes on a public or private X.25 network, you might wish to use the DTC/X.25 iX Network Link.

Special Cases

The following sections describe certain design requirements for special situations, such as shared dial links, personal computers, and using non-HP e3000 minicomputers on an NS network.

Shared Dial Links

Shared dial links have two limitations that must be considered when designing a network. First, a shared dial link cannot be used as an intermediate link in a Point-to-Point network. Any other kind of dial link can be used for intermediate links, but shared dial links can be used only to connect leaf nodes (that is, nodes that receive messages targeted only for themselves, also referred to as end nodes). Second, cannot dial out on SMUX, shared dial links cannot be used as gateway halves.

Non-HP e3000 Nodes (Including PCs)

LAN, Token Ring, FDDI, 100VG-AnyLAN, 100Base-T, and X.25 networks can access non-HP e3000 nodes. Point-to-Point networks must be composed of only HP e3000s.

Applicable SYSGEN Parameters

VT terminals are not physical devices, instead they are virtual devices created dynamically at remote logon, header entries are created for the maximum number of VT terminals at system boot time. The exact number of head entries created for VT terminals will depend on the value of MAXDYNIO (which is configurable in SYSGEN).

The exact number of remote sessions which can be supported on a given system will depend on the exact mix of jobs and sessions (remote and local, active and inactive) on that system.

Chapter 2

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