| I am interested in Digitals hub & hub modules. As I gaze through some of the
>information available at hands I get some of these doubts.
>1. Is it MIB 1 or MIB 2 implemented in DEChub 900 Multiswitch ?
MIB-II is implemented in the Management Agent Module, and in many of the
line cards. In addition, several other private and public MIBs are
implemented.
>2. What is the type of bus architecture used in hub backplanes ? Is it segment
> bus, multiple bus, multiplexed bus, system bus or any other kind of bus ?
As the "DEChub900 MultiSwitch Owner's Manual" states:
"This hub is a high density hub that is capable of supporting
multiple network technologies. A flexible channel architecture is
used to support Ethernet, Token Ring, and FDDI technologies, as
well as higher speed emerging technologies such as ATM."
The Owner's Manual is part number EK-DH2MS-OM.B01.
>3. Is Digital coming out with any stackable hub ?
Contact the product manager for information about hub futures. (I believe
the product manager is Steve Allen [nac::allen]).
I think our latest marketing information claims that the DEChub product
line is already "stackable" since modules work either in a hub or standalone.
-Shawn
[
|
| Thanks for your quick reply. I would like to make my questions in .0 more
clearer.
1. Is it MIB 1 or MIB 2 implemented in DEChub 900 Multiswitch ?
In DEChub 900 features it is given that it provides built_in manageble
platforms that include SNMP stack & chassis MIB.
So wich is this MIB ?
2. What is the type of bus architecture used in hub backplanes ? Is it segmented
bus, multiple bus, multiplexed bus, system bus or any other kind of bus ?
There is an article in PC magzine on Enterprise Hubs dated 10 Nov 1992. Here
they mention Lannet & Cabeltron have segmented bus, Chipcom have multiplexed
bus in their hub backplanes.
So what is that Digital hubs have in their backplane ?
Any ideas ?
Thanks in advance
Rajesh
|
| Rajesh,
The chassis MIB is neither MIB-I or MIB-II.
All SNMP manageable devices are required to support the standard "Management
Information Base for TCP/IP Based Internets. MIB-II is a superset of
MIB-I. We support MIB-II.
In addition to MIB-II, products support other standard MIBs. For example,
our repeaters support the standard repeater MIB. Our bridges support
the standard bridge MIB. Our ethernet products support the Ethernet MIB,
and our FDDI products support the FDDI MIB.
In addition to standard MIBs, products implement "vendor extensions" to MIB.
The chassis MIB is "vendor extension" which is owned by DEC and distributed
freely. The chassis MIB was written to solve problems particular to hubs.
The is no standard chassis MIB -- if there were, we would have used it
instead of inventing our own.
One of the problems with SNMP-based hubs is that the is no way to address
multiple components of the same type. For example, if you have more than
one bridge in a hub, there's no way to identify an individual bridge other
than thru a separate community. The chassis MIB provides "slot" and
"entity" table which keep track of the various communities in use within
the hub.
There is also not a standard MIB for hub power, environmental, and backplane
management. The chassis MIB contain object which help manage these things
in a hub.
You can get a copy of the chassis MIB via anonymous ftp to gatekeeper.dec.com.
It's in the /pub/DEC/hub900/mibs area. Get the README file first.
Hope this helps.
-Shawn
|
| >2. What is the type of bus architecture used in hub backplanes ? Is it segmented
> bus, multiple bus, multiplexed bus, system bus or any other kind of bus ?
> There is an article in PC magzine on Enterprise Hubs dated 10 Nov 1992. Here
> they mention Lannet & Cabeltron have segmented bus, Chipcom have multiplexed
> bus in their hub backplanes.
> So what is that Digital hubs have in their backplane ?
I don't know. These are not industry standard terms. I suspect that if
you want someone to categorize the bus into one of:
segmented,
multiple
multiplexed, or
system
then you will have to define your terms. A better approach might be to ask
about the DEChub900 bus, and see how it fits into the definitions in
your PC magazine article.
I'll give you an overview of the DEChub900 backplane.
The DEChub900's bus employs "flexible channels". There are a bunch of
terminated etch on the backplane. These etches can be used for *any*
lan technology. You can connect Token Ring, Ethernet, FDDI, ATM, and
whatever else to the backplane.
These signals are just terminated etch. When we discuss the backplane,
we talk of the upper and lower connectors. The upper connector is the
old DEChub90 connector. (Some other stuff has been added -- but that's
just detail.) The lower connector connects to the DEChub900 matrix.
We divide the matrix into 14 "channels". "channels" consist of 6 wires.
Different technologies use the wires differently. For example, if a channel
is used for FDDI, more of the 6 wires are used than if the channel were
used for Ethernet.
The design of modules dictate how the module connects to channels. This
means that although there are 14 channels, not all modules can connect
to all 14 channels. For example, the DECrepeater900TM can only connect
to one of 6 matrix channels, while the DECconcentrator900MX can connect
to any of the 14 channels. Channels used differently is bus and ring
topologies. ATM can be added to the hub because of the flexible design.
HubWatch and the Management Agent Module hide many of the details of the
matrix from users. Users don't have to care that the DECrepeater900TM
can only connect to 1 of 6 of the matrix channels.
That's a very brief overview. Does it help you categorize the the
DEChub900 matrix? Do you have any other questions about the matrix,
other than what type it is?
-Shawn
|