Input Output Fabrics - Dell EMC PowerEdge MX7000 Field Service Manual

slot. The MM can then drive the signal HIGH to enable the AUX power on the module. The IOM_PRES_PWR_ON function the
same way. The active MM drives the signals as they are tied together at the ECs.

Input output fabrics

The internal connection of the main I/O subsystem in MX7000 enclosure is referred to as fabric A and B. These fabrics are
connected using a direct orthogonal connection between sleds in the front of the chassis and I/O fabric modules in the rear.
The mating connection on the sleds is on the mezzanine cards, which can install into location A or B on the sled. The usage of
mezzanine cards provides flexible I/O fabric options to choose from, such as Ethernet or Infiniband.
Each fabric A and B allows for two IOMs (that is, A1 and A2, or B1 and B2) for redundancy. Each IOM connects to all 8 compute
nodes through the orthogonal connectors. The connection from the IOM to each compute node (The mezzanine card on the
compute node) is a x8 bi-directional link. Depending on the interface, all the lanes within the link may not be used, however the
x8 provides a path for future high-bandwidth fabric types.
Standalone pass through modules
Two stand alone Ethernet pass through modules are supported to the initial release, a 10G (Base-T) and 25 GbE pass through
module. The pass-through IOMs plug into the fabric A or B IOM slots in the chassis. These IOMs redrive, or pass through the
link signals without any switching. Each shall provide 16 internal server-facing ports and 16 external user-facing ports.
NOTE: Only the ports 1-8 are active, when compute sleds with dual-port mezzanine adapters are configured with the
pass-through modules. The ports 9-16 require a quad-port mezzanine adapter.
Front sled to rear port mappings
The external port assignments of pass-thru modules are fixed due to the direct routing connection internal to the system and
the IOM itself.
NOTE: If storage or other peripheral sleds are installed that do not support fabric A/B connections, the corresponding ports
on the I/O modules mapping to these slots are not active. This is also the case for any compute sled that does not have a
mezzanine card that is installed for the particular IOM (A or B) in the system.
A standard size compute sled is configured with dual port fabric A/B mezzanine maps to a single port on each (A or B) I/O
module.
Table 20. Compute sleds dual-port mapping
Compute sled
1
2
3
4
5
6
7
8
Table 21. Compute sleds with quad-port mezzanine cards mapping
Compute sled
1
2
3
IOM x1 (top)
1
2
3
4
5
6
7
8
IOM x1 (top)
1, 9
2, 10
3, 11
IOM x2 (bottom)
1
2
3
4
5
6
7
8
IOM x2 (bottom)
1, 9
2, 10
3, 11
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