IBM Nortel Networks L2/3 - Gigabit Ethernet Path

Chapter 2. IBM Eserver BladeCenter overview 9
2.2.3 Gigabit Ethernet path
Figure 2-5 on page 10 illustrates the Gigabit Ethernet path. Each processor blade has a
minimum of two and a maximum of four EtherLAN interfaces. In particular, the BladeCenter
HS20 processor blade has two serializer/deserializer SERDES-based Gb Ethernet interfaces,
one for each midplane connector. With a daughter card installed, two more network interfaces
can be added. Each switch module (SW Module) receives one LAN input from each
processor blade, for a total of 14 inputs.
The following partial listing illustrates the routing:
򐂰 Processor blade 1 LAN 1 → Switch Module 1 input INT1
򐂰 Processor blade 1 LAN 2 → Switch Module 2 input INT1
򐂰 Processor blade 1 LAN 3 → Expansion Switch Module 3 input INT1
򐂰 Processor blade 1 LAN 4 → Expansion Switch Module 4 input INT1
򐂰 Processor blade 2 LAN 1 → Switch Module 1 input INT2
򐂰 Processor blade 2 LAN 2 → Switch Module 2 input INT2
򐂰 Processor blade 2 LAN 3 → Expansion Switch Module 3 input INT2
򐂰 Processor blade 2 LAN 4 → Expansion Switch Module 4 input INT2
On processor blade, LAN 1 and LAN 2 are the on-board SERDES Gbit Ethernet interfaces,
and are routed to Switch Module 1 and Switch Module 2, respectively, for every processor
blade. LAN 3 and LAN 4 go to the Expansion Switch Modules 3 and 4, respectively, and are
only to be used when a daughter card is installed. Unless a daughter card is installed in one
or more processor blades, there is no need for Switch Modules 3 and 4. Further, the switch
modules have to be compatible with the LAN interface generated by the processor blade. If a
Fibre Channel daughter card is installed in a BladeCenter HS20 processor blade, Switch
Modules 3 and 4 must also be Fibre Channel-based, and any daughter cards installed in the
remaining BladeCenter HS20 processor blades must be Fibre Channel.
Note: On the Nortel Networks L2/3 GbESM, the internal Ethernet ports on the switch are
referred to as MGT1 and MGT2. For more information beyond this generic illustration, see
Chapter 4, “Nortel Networks Layer 2/3 GbE Switch Module architecture” on page 21.