Black Box 5000 manual Network Design and Topologies, Initial Considerations

Multiserver 5000

3. Network Design and Topologies

3.1 Initial Considerations

The Multiserver 5000 offers the ability to connect one of the following units and their associated links:

•Multiserver (1000 or 5000) via an Interconnect Link.

•Feeder Mux (Communication Box II or Statplex Multiplexor) via a Mux Link or an X.21 Link

The interconnect link can be connected using the integral MS1 56K CSU/DSU module. Any of the links can be connected using an external ISU or modem. If the external devices are not

RS-232, the appropriate converters are required.

The Multiserver 5000 supports four types of network topologies:

•Point-to-point

•String

•Star

•Distributed Star

Utilizing these topologies, the Multiserver 5000 can serve as either a terminated node (traffic is terminated in, or attached to the local node) or a

switching hub (no local attached devices). Without local traffic (data/voice/LAN), the Multiserver’s link capacity increases.

There are three elements to be considered when putting together a Multiserver 5000 network:

•Channel Performance

Burst	288	Kbps
• Link Capacity
Terminated	72	Kbps
Switched	192	Kbps
• Delay (varies	Do not exceed six link
between channel	hops in any network
type and protocol)	path (6 node hops)

Important

You cannot have a closed loop in a Multiserver network.

When designing a Multiserver network, it helps to keep in mind the different capabilities of the Multiserver 1000 and Multiserver 5000. A summary of these are detailed in Table 3-1.

Table 3-1. Comparison of the Multiserver 1000 and the Multiserver 5000

	Multiserver 1000	Multiserver 5000
Number of possible interconnect links	1 (A1)	3 (A1 to A3)
Speed: interconnect link	1.2 to 64 Kbps	1.2 to 72 Kbps
Number of possible feeder-mux links	1 (A1)	5 (A1 to A5)
Speed: feeder-mux link	Up to 19.2 Kbps	Up to 19.2 Kbps
Max. number of data channels	41	41
Max. number of sync data channels	1	10
Sync protocol speeds (most applications)	1.2 to 19.2 Kbps	1.2 to 38.4 Kbps
Max. number of voice/fax channels	4	8
Dual-link load balancing capability	no	yes
Multi-point capability	no	yes

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