NonStop S-Series Planning and Configuration Guide (G06.29+)

ServerNet Communication Pathways
HP NonStop S-Series Planning and Configuration Guide—523303-021
6-15
Communication Pathways in Different Topologies
Communication Pathways in Different
Topologies
In both of the following subsections, groups 01 and 31 are communicating over the X
fabric. However, the pathway between them goes through different SEBs and different
ServerNet connectors.
Tetra 8 Topology Tetra 16 Topology
For the X fabric, a system can
have an SEB only in slot 51.
For the X fabric, a system can have SEBs in slots 51
and 53 of the inner tetrahedron.
Each processor enclosure
supports one SEB for each
ServerNet fabric.
Removing an SEB from a
processor enclosure disconnects
that processor enclosure and all
associated I/O enclosures from
that ServerNet fabric.
Each inner tetrahedron processor enclosure can
support up to two SEBs for each ServerNet fabric.
Each outer tetrahedron processor enclosure can
support up one SEB for each ServerNet fabric.
Therefore, removing an SEB from a processor
enclosure has one of two results:
Removing SEB 51 (or 52) disconnects that processor
enclosure, plus all its associated enclosures, from the
ServerNet fabric associated with that SEB.
Removing SEB 53 (or 54) disconnects the I/O
enclosures associated with that SEB from that
ServerNet fabric, but does not disconnect the processor
enclosure itself from the fabric.
SEB ServerNet connectors 4 and
5 can connect to I/O enclosures.
ServerNet connectors 4 and 5 on an SEB connect
differently:
In the inner tetrahedron, SEB ServerNet connectors 4
and 5 in slot 51 (and 52) can not connect to I/O
enclosures.
In the outer tetrahedron, only SEB ServerNet connector
4 in slot 51 (and 52) can connect to an I/O enclosure.
In the inner tetrahedron, SEB ServerNet connectors 4
and 5 in slot 53 (and 54) can connect to I/O enclosures
Each processor enclosure
connects to a ServerNet fabric
through one SEB ServerNet
router.
Some processor enclosures connect to a ServerNet
fabric through two ServerNet SEB routers.
For example, group 05 connects to the ServerNet fabric
through group 01. Therefore, group 05 depends on
group 01 for communication with the ServerNet fabric.
If group 01 is disconnected from the fabric, group 05 is
disconnected as well.