BladeCluster Solution Manual

3 Advanced Cluster Hubs (ACHs)
NOTE: OSM refers to the Advanced Cluster Hub as a patch panel.
This chapter describes the Advanced Cluster Hub (ACH) which is used to connect processor switches
and ServerNet switches in a BladeCluster topology.
Advanced Cluster Hub (ACH) Description
The ACH is used to connect the processor switches and ServerNet switches in each node within
the zone along one fabric as described in “Connections to the Advanced Cluster Hubs” (page 43).
Using an ACH reduces the number of cable connections per fabric. All cables that are connected
to the ACH from each ServerNet switch or processor switch in a node are bundled together using
Multifiber Terminator Push-on (MTP) to MTP cables (for ACH to BladeSystem connections) or MTP-4LC
cables (for ACH to NS16000 connections). Each cable supports four ServerNet connections
between the ACH and the processor switch (via MTP-4LC) or ServerNet switch (via MTP-MTP). All
the connections between individual nodes within the zone are made inside the ACH.
ACH Hardware
NOTE: ACHs can be installed in a separate rack and do not have to be installed in the same
rack as the BladeSystem or NS16000 series node.
TIP: Service providers, if you are installing the ACHs in the same rack as a BladeSystem node,
HP recommends installing the ACHs at the U37 and U39 rack level as shown in Figure 7 (page 40).
For ACHs in a NonStop NS16000 series node, HP recommends installing the ACHs toward the
top of the rack. For example, you could install an ACH at the:
• U37 and U39 rack level when there are dual maintenance switches at the top of the rack
• U39 and U41 when there are no maintenance switches at the top of rack as shown in Figure 8
(page 40)
• U41 when an IOAM enclosure occupies U30–U40 and there are no maintenance switches
at the top of the rack, although one ACH would require installation in a separate rack
An ACH has these characteristics:
• 2 U high rackmountable FRU that contains no replaceable components inside. There are no
LED indicators, power supplies, or fans.
• The ACH is a passive component and does not require (electrostatic discharge) ESD protection.
• Contains 32 MTP connectors. Each connector supports four ServerNet connections from a
processor switch (MTP-4LC) or ServerNet switch (MTP-MTP).
• Supports up to eight nodes in a single zone.
• Supports 14 ServerNet links from each node along a fabric.
38 Advanced Cluster Hubs (ACHs)