| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 2916.1 | | NETCAD::BRANAM | Steve, Hub Products Engineering, LKG2-2, DTN 226-6043 | Fri Oct 27 1995 14:22 | 31 |
| As long as you don't exceed the maximum distance on the serial management bus
cables between the stack units, this should work. However, why the "mgt bus
return"? Unless something has changed since I worked on this in the lab or I am
misunderstanding your question (both distinct possibilities!), I believe your
picture should be:
DS900EE
| | |
F.O.cable | | | utp
___________________| | |___________________
| | |
| |utp |
| | |
90FS mgt.bus 90T-16 mgt bus 90T-16
| _____________| | _____________| |
| | | | |
| | 100 ft | | 100 ft |
90T-16 | 90T-16 | 90T-16
| | | | |
| | | | |
| | | | |
90T-16 | 90T-16 | 90T-16
|________| |_______|
Here the management bus starts at the 90FS, goes down to chain the two 90T-16's
with short serial hops, goes across the 100 ft. run to chain together the middle
group of three 90T-16's, goes across the next 100 ft. run to chain together the
rightmost group of three 90T-16's, and ends at the lower right unit. The FO and
UTP cable segments are not part of the management bus. There is no need for a
managment bus return path, since it already has a full-duplex path from the 90FS
to the lower right 90T-16. The 90FS manages itself and the eight 90T-16's.
|
| 2916.2 | I may be wrong... | VAXRIO::ROLF | Vaporware Design Specialist | Fri Oct 27 1995 15:33 | 10 |
| Thanks Steve,
fine, but I thought I read somewhere that the managment bus can be
closed, so that any module can be removed from a live stack without
interrupting managment. It is quite possible that the "return" isn't
really required, as long as one doesn't remove a module.
Thanks again and have a nice weekend
Rolf
|
| 2916.3 | | NPSS::WADE | Network Systems Support | Fri Oct 27 1995 16:05 | 5 |
|
The ring configuration gives it the "management network resiliency".
Bill
|
| 2916.4 | Oops! | NETCAD::BRANAM | Steve, Hub Products Engineering, LKG2-2, DTN 226-6043 | Fri Oct 27 1995 16:54 | 4 |
| Yes, Rolf, you are correct, you can connect the management bus in a loop to
tolerate a single break anywhere in it (sort of like FDDI ring wrap, only
cheaper!). This was apparently a capability identified fairly late in product
development, so I apologize for confusing things.
|