Specifications

Chapter 1. Introduction to IBM System Networking 10Gb Ethernet products 45
򐂰 Up to eight module bays for communication and I/O switches or bridges: The modules
interface with all of the blade servers in the chassis and alleviate the need for external
switches or expensive and cumbersome cabling. All connections are done internally
through the midplane. Two module slots are reserved for hot-swap/redundant Gigabit
Ethernet switch modules. Two slots support either high-speed bridge modules or
traditional Gigabit Ethernet, Myrinet, Fibre Channel, InfiniBand, and other switch modules.
Four additional slots are dedicated for hot-swap/redundant high-speed switch modules. All
modules, when installed in pairs, offer load balancing and failover support.
򐂰 Bridge module: Dedicated bridge module bays do not exist in IBM BladeCenter HT. I/O
bays 3 and 4 are similar to IBM BladeCenter H, but bridge bays 5 and 6 do not exist. IBM
BladeCenter HT I/O bays 1 and 2 do provide bridge module support, but no hybrid
bridge/Gb switch modules are planned at this time.
򐂰 Interposers: AMMs and I/O (switch) modules are all in the front of the chassis with the
blades. Because they plug into a common midplane with the blade servers, they require
interposers in each populated I/O bay to make up the difference in depth between switch
enclosures and blade server enclosures. These interposers are entirely passive, and
extend the midplane out to the rear connectors of the I/O modules. Figure 1-24 shows the
interposer.
Figure 1-24 IBM BladeCenter HT Interposer - used for extending the midplane to connect the high
speed I/O modules.
򐂰 Interswitch Links: Because IBM BladeCenter HT has two unimplemented blade ports (13
and 14), the IBM BladeCenter HT midplane provides interconnects between switch ports
13 and 14 for the following matched pairs of switch modules: 1-2, 3-4, 7-9, 8-10. These
pairs must be enabled by specifically designed switch interposers that complete the link
between the switch module ports 13 and 14 and the midplane paths. If matching
interposers do not both have the ISL support, then the switch module ports is not
connected. Interswitch links between matched pairs of switch modules allow additional
functionality, such as link aggregation or stacking, if supported.
Ethernet switch modules, network interfaces, and port designation in
the IBM BladeCenter HT
It is important to understand how blade server options and their associated ports are
allocated within the BladeCenter chassis and which ports, within a blade server, map to the
different I/O bays within the BladeCenter chassis. There are additional switch connection
considerations when using the IBM BladeCenter HT.