Black Box 5000 - Manual (Page 28)

Multiserver 5000
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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.
3. Network Design and Topologies
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