Expanding upon the example in 4a and 4b above, figure 4C illustrates some of the flexibility
of the 4108gl. By adding another 100/1000 Switch GL Module, dual homing the application
servers, and evenly distributing the NAS and application server connections between the two
100/1000 Switch GL Modules, you now have a load balancing, high availability solution.
Since the 4108gl supports an optional RPS and hot swappable modules, you are protected
against power supply failure as well as 100/1000 Switch GL Module failure in this example.
If one of the 100/1000 modules fails, traffic can still be supported on the other 100/1000
module until the failed unit can be hot swapped.
gigabit aggregation
Since HP introduced the first commercially available gigabit Ethernet interface capable of
using Category 5 copper cable in October 1999, prices for gigabit connectivity have steadily
decreased. This has created a demand for affordable, high performance, high-density gigabit
Ethernet switches. The HP Procurve Switch 4108gl can provide a solution for this where
simple, fast, Layer 2 gigabit aggregation is desired. The HP Procurve Switch GL 100/1000
Module (J4863A) and HP Procurve Switch GL Transceiver Module (J4864A) for the 4108gl
provide intra-module wire speed gigabit switching. For inter-module switching, the high-
speed 36.6Gbps central switching fabric provides more than enough throughput for most
applications.
Using HP Procurve Switch GL 100/1000-T Modules (J4863A), which have 6 RJ-45 ports
each, you can populate all eight slots of a 4108gl and get 48 ports (6 ports x 8 slots) of
-T
100/1000-T connectivity. In this case, if all eight modules only need to provide intra-module
switching, you can get up to 71.4 Mpps throughput! Most installations will see maximum
performance of between 21.6 Mpps (the central switch fabric speed) and 71.4 Mpps.
The HP Procurve Switch GL Transceiver Module (J4864A) provides 3 transceiver slots that
accept any combination of gigabit SX, LX, 100/1000-T, Gigabit Stacking, and 100Base-FX
transceivers. Figure 5a provides an example of using the 4108gl as a gigabit aggregator
switch.
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